I had to diagnose a stalling problem on a 95 Stratus 3.5. Long story short fuel trim max high bank 1 and then max lean on bank 2. When reset it would run for a few minutes until the trims would do it again but sometimes swap sides. Long story short the engine had been swapped with 1 year newer and bank 1 & 2 were reversed in the harness on that year model. Computer would see bank 1 go lean and enrich bank 2, bank 2 seen rich and lean bank 1 some more. That was a fun one.
Hey Dan I know this video is a couple of years old but it just saved me over $2000 dollars. 2006 Acura TL 216,000 miles P0420 catalyst below threshold bank 1. But short term and long term fuel trimmed maxed out. Downstream sensors were reading lean condition.Sprayed carb cleaner to verify downstream o2 sensors were working. They were. Long story short coolant temp sensor was +40° off. Making the ECU think the car was hotter than it was and giving less fuel. Which the o2 sensors were reading and ecu trying to compensate with fuel trim. No 02 sensor replacement ($200 × 4) no catalytic converter replacement ($600 ×2). I do my own work (free). $30 coolant temp sensor fixed everything. Cant thank you enough. If you're ever in NYC I owe you a ton of beers.
Not to mention the safety risk and health effects. My shop refused to provide us with safety glasses, mask, ear plugs or knee pads. They provide a cheap safety shoe once a year so if you worn it out, they wont replace it for you. The gloves they gave are cheap cloth ones, not oil resistant nitrile. Used engine oil causes cancer
Poor pay? My tuner charger me 1100 for 4 hours of dyno tuning. Y'all charge 80 to 120 per hour for labor. How's that poor pay? I was a mechanic for the army for 14 years. It's not hard labor. And tuning requires knowledge. But that's it.
@@Diagnosedan Great thanks to your wife, otherwise we never know if you would try to prove yourself opposite by explaining us thinks in such an excellent way. So, when she says so, let's think this is the way how she develops your talent.
@@Diagnosedan all wifes are the same. Women, they hate each other, and they're partners/husbands (after a while..) because we share and admit the clever among us, while them/they're, nothing like that.. brotherhood of man. And I swear I am not misogin..
Now in my sixties and having left the auto technician career behind (25 years ago) for tool and die, I'm thinking of a return. Of course it'll be my own shop. Who would hire an old guy? With your ability to explain various systems you've brought back my mojo. I totally understand you. Thank you for these videos. You are an inspiration.
I am watching this video over and over again. Amazingly that other shop replaced a common part that would affect both banks (the MAF sensor) when the vehicle only had an issue with bank 1. Too many parts replacers out there in the industry without "diagnostic" skills. I see it as "keep on throwing parts at the vehicle till the problem goes away"...sorry, but not on my wallet. I love these videos!
Awesome video, So many great uses for brake cleaner lol... another way to verify O2 and A/F ratio sensor operation from the driver seat (on vehicles with vacum power brakes) is to pump the brake pedal rapidly for a few seconds, this will force the system lean and when you stop pumping the brake pedal the system will go rich for a little bit. All you have to do is monitor the sensors and see which one is not responding 😊
Just discovered your awesome channel. I guess the answer to your question is the fact that there is no throttle valve on this particular model. That role is taken by the Valvetronic system.
You have been my great teacher,since i started following u up i have improved i lot in my career as auto electricians. I want to say a big thanks to u.
That BMW uses a Valvtronic system. Basically it can control valve lift electronically which pretty much eliminates the need for a throttle plate and this is the reason there is no vacuum at the manifold because air flow is controlled by controlling valve lift instead of a throttle plate. This system is very similar to what Nissan Calls VVEL (vairable Valve Electronic Lift). It's pretty slick.
Watching this video 4 years after it came out and im amazed. Dan, thank you for setting this up and explaining all of this simple and very easy to understand!!
Thanks to your videos I learned to look at my data and it helped me to diagnose an 05 Infiniti with a long crank time and lean readings on both o2 sensors. No lean codes were stored and car ran perfect when it started.
I have a 2001 330i coming in Friday. While I was servicing the A/C system he was telling me about the problems he has been having with the vehicle. I scanned it and found numerous codes related to the O2 sensors on banks one and two as well as a Number one misfire. I also found a DME fault code. He told me numerous shops have replaced the O2 sensors MAF Sensor and it had a tune-up. He is bringing the vehicle back Friday for a more though diagnostic. I will have a plan of action in place to better diagnose his vehicle's issues. Thank you for a very informative video on the Wideband O2 sensors and fuel trims.
You see i am not having any such problem on my car, i am not even a mechanic, however i really enjoy your shows. They are informative and nicely presented. You are way better than lots of teachers and some tv shows.
Diagnose Dan, you are the MAN!!! I ran across one of your videos the other day and I am such a fan now. You are exactly what the new generation needs as a common sense back to basics teacher. You are mandatory must watch for my younger crew. Keep doing what you do and we will keep subscribing, watching and spreading the word!!!
This is a very good video presented in a methodical manner. To answer your final question about why that engine had pressure in the manifold it is a valvetronic engine. As a former BMW trained technician the initial give away is the bulge in the valve cover. Not sure if you have done a video on that system as this is the first off you videos I have seen Regards Ian
Well I didn't know what Valvetronic is since I do not own a BMW car (my last one was a 1995 E36) and my BMW motorcycles do not use that system either. My guess was a MAP sensor only needs a tiny hole to measure pressure (since it is static and not dynamic) and that tiny hole would not allow enough air to enter the engine. But this video is excellent to understand about Fuel Trim (I had no clue about trim)! My friends Porsche 993 is running ultra rich after having the engine out for seals, o-rings and a new dual mass flywheel and clutch. Plus we did the 964 mod to the 993 cams to pin the timing gears to the camshaft (the original 993 gear is a butt fit to the camshaft using a bolt...in my books a no-no). Anyway, I think we will have to do an ECU Drive Cycle / Readiness. Thumbs Up Dan!
I like watching people like Dan, intelligent ,funny love what he does. I like to help and teach people too, feels so good,, the more we learn the better we get. this world will be better
Watch your videos a lot. You are the best! As a long time shop owner I often use your instruction to help my techs to never forget the basics! Your breakdowns are awesome! Thanks for all you do for our industry!!!
A another easy to understand lesson. Thank you for all your sacrifices you made in order to offer these videos to us! I Can't stop watching your videos, they're so contagious! :-)
I have a Commodore with a Buick derived engine. { Australia) I will stick with its simplicity compared to these Euro engines with multiple O2 sensors and variable valve timing. So far 280,000 kilometres and still on original injectors and sensors. I can do a lot of the work myself unlike these complex cars which need some expensive equipment to diagnose. Still very fascinating learning how all this new fangled stuff works. Really appreciate your time and dedication producing this training grade series.
Great video, Dan. I'm a long-time self-taught garage mechanic working mostly on German cars, especially on BMW's. And I'm also learning even more by just watching this video. To answer your bonus question, I think there is still a slight vacuum after you remove the MAP sensor, or else, this Naturally Aspired combustion simply won't work. And the reason that even when you articulate an artificial leak in the intake manifold and still maintained a stoich condition is because of BMW's VALVETRONIC system in place. Under the VALVETRONIC system, the throttle body no longer plays a key role in intake air control. In fact, you can have the throttle body fully open the whole time and it won't make a difference as long as the O2 sensors are properly working and nothing being wrong with the fuel supply. Actual fine control of the air is done by the intake cams which is fully modulated by the VALVETRONIC system.
You have that ability to explain complicated things in an easy way...great job danny, btw i've scrolled down almost all the comments and haven't found the ansewer...
my friend, you are right, in engines with valvetronic there is no vacuum in the intake manifold, one way to create vacuum would be to disconnect the valvetronic motor to force the system to work with the throttle body in this way, the throttle valve now will be closed, and there will be vacuum in the intake manifold. I read you Dan 👍🏽 from Peru
I have been driving myself insane troubleshooting a failed smog on my 98 boxster. Fuel trim negative, indicating rich. But downstream shows 0.1 or 0.05, lean. This video explained clearly that it's likely an upstream. Untill now I have been watching voltage instead. Thanks for the help.
Hi Dan, great videos. My car has a sudden 20% increase in fuel consumption, but no other noticeable changes or codes. This is more noticeable when the engine is cold, but still higher than normal at operating temp. My long term fuel trim stays between 5.5 and 10.9 (normally the low is 8%, it only takes very short dips to 5.5), and short term stays between -2.5 and 1.5. I think I have a lazy o2 sensor - the manual recommended it to be changed 20,000 km ago. Upstream is wideband, LAMBDA normally stays at 1 while cruising, but sometimes bounces between .9 and 1.1. It will spike to 2 when throttle goes from high to close. mA normally is around 0.7, but will spike to 3.2 when throttle goes from high to close just like LAMBA. Downstream is regular o2, when car is warming up it stays low around .005. It climbs as engine is warming and then stays around 0.7 while idle and bounces between .1 and .9 while driving. I have no signs of a bad catalytic converter, so should I just replace both sensors?
Well I'm not a fan of just replacing parts. The numbers your giving me ain't great but not to bad either. See if the fuel trims improve with higher Rpm's. Also check your temperature sensors!
@@Diagnosedan Hey, I forgot to come back to tell you! I started monitoring my coolant temp and noticed it always stayed between 170-185 when warm without any symptoms of an open thermostat. I pulled the temp sensor and it was covered in a film. Changed it out for $5 and my car is running great again! You da man Dan!
Very informative... After replacing my injectors, I started noticing backfiring.. I never thought a lean condition could cause that.... Your video has inspired me to send the injectors off to be tested and after I replace them, I'll check my O2 sensors. Thank you
Smashing video once again Dan. This test can also be used to diagnose a fuel injector fault! Running lean and both o2 sensor working ok but engine runs better adding brake cleaner means injector fault. Watching the smooth running values on these engines also helps understand the cylinders which aren't performing well, positive numbers indicate less mechanical output of the cylinder. Dont forget on most newer BMW and mini deleting codes doesn't reset the fuel trim adaptations or injector learnt values etc , so you may change faulty parts and car still runs bad with learnt values which are incorrect. Injectors for all gdi engines must be coded.
Awesome video thank you Dan the man . System bmw came out with I believe it’s called vanos which requires no throttle plate so that engine rpm is changed through variable valve lift
I watch your video as a good series. Not every educational institution explains so well. As they say there are no bad students, there is a bad teacher.
13:36 Because the engine has a valvatronic system, which replaces the operation of the throttle valve, and instead of it, the valves open at a certain height, and not the throttle valve. And the typical pressure in the intake manifold is close to 950 millibars normal atmospheric pressure is 1013 millibars. Typical vacuum in most naturally aspirated engines is 300...350 millibars.
Great content in this video! I am surprised that BMW does not have a back up fuel strategy for circumstances like this, a lot of the Asian vehicles use downstream fuel trims when they have a upstream wideband
A quick question Dan, can you tell a narrow band from a wide band just by looking at them. Just watched this video of yours for the 4th time. Brilliantly explained. I’ve even shared it with my work colleagues. You’ve even started a catch phrase in my garage. When I fix something I turn to the other guys and say “ diagnose Paul fixed it again”🤣
Ha ha thats awsome! Narrowband sensors usually have 4 wires and wideband sensors usually have more. If you follow this rule your right 95% of the time😉 Thanks for the comment DiagnosePaul💪
You are a great teacher Dan!👍🏼 thank you! If I’m not mistaken that BMW also have an absolute pressure sensor in the intake manifold, which will not sense an intake air leak.
The throttle valve is used for start up and shut down other then that the valve Trinidad system varies valve lift to near 2mm at idle and controls volumetric intake during so and upon hard torque demand the lift is increased as needed
Excellent explanation ,I now understand how it works. Is there a quick and easy way to identify which type of sensor we are testing? I assume that a wide band sensor has more wires than a narrow band sensor but is there anything else to look out for identification? Just found one of your previous answers to the same question, should have read further. Thanks for a brilliant video.
One comment. It would make things a little clearer if you also explained that the fuel trims only/primarily react to the upstream sensor and not the downstream sensor, otherwise one of the best case studies I have seen. Thanks
I just got an 08 Sienna in here. Wide band sensor. Misfires on one bank. This video is so helpful. Fake Diagnose Bill is going to TRY to fix it again with COOL REAL Diagnose Dans help.
Awesome and very clear explanation! It was like I was in school! Subscribed! Also I was wondering who has answers on that last one, why the non-turbocharged BMW has positive air pressure on idle and not vacuum?
You seem to have a better understanding about this topic than most. Please help me. I recently installed long tube headers in my car, with catalytic converters. Following common practice, I also installed sensor spacers. This eliminated the P0420 and P0430 codes, but I'm now getting P2096 and P2098 codes consistently. The car is a 2018 Mustang GT. The headers are 1 7/8 inches going to a true 3" cat-back exhaust. As I'm sure you know, the pre-cat oxygen sensors are wide band, and the post-cat sensors are narrow band. The car has an aftermarket tune. It runs well, and the air/fuel mixture hovers around 14 (I assume it's lower than 14.7 because of the 10% ethanol, 91 octane gas I'm running), and the tuner probably made it a bit rich. My mechanic confirms there are no exhaust manifold, exhaust, or unmetered air leaks. The tuner won't turn off the post-cat sensors, which is understandable. Questions: can you confirm that P2096 and P2096 actually indicate that the mixture is too rich (rather than lean), because the bigger exhaust is throwing off the post-cat oxygen sensors? Second, if this is the case, is it ok to continue to drive like this, occasionally clearing the CELs? Please help.
Hey Dan Thanks for posting these videos your are a great teacher. I have been watching your videos for a little while now and I have learnt alot. I have been applying your technical advice in the field and using scopes more often than I use too. I try keep it simple and not be a part changer thanks to you and several out their I am becoming better and enjoying diagnosis more. I will try to to pass the torch. Of knowledge to our fellow technicians out there as you are. Thanks again. For the answer to question for no vacuum on bmw its due to the valve tronics it act like the throttle and the actual throttle stays open all the time which does not allow negative pressure (vacuum). Bmw actually installed a vacuum pump driven by engine camshaft. I think when system goes on fail safe throttle may operate like a normal throttle open and closing not sure correct me if I am wrong. Anyway keep up these great videos and I will keep watching. Your awesome
It's interesting... Always new guys need learn old knowledge. I have tried to figure out how this works for a couple of weeks, and even though I have looked at this video sometimes, I have forgot it and the video. But now I have to copy the whiteboard information into my notebook! 😁 Maybe I then can get more information from the data shown in certain apps, otherwise we have to improve the apps. How difficult can that be? Dan, you are an angel, or you was also five years ago. One difference, you looked somewhat younger five years ago... 🥺
@@fitrimaryandhi9105 The BMW valvetronic system uses not only variable valve timing but also can vary the lift of the valves from less than 1mm at idle to several mm under full acceleration ( Don't know exact specs). Under normal operation the throttle plate stays 100% open and air flow is controlled by varying the valve lift in response to driver demands.
This reminds me of the time I had to diagnose a 1990 Dodge pickup with V8 and automatic. When cold and warming up, ran great. Once it reached operating temperature, it would chuff and chug and misbehave. The single O2 sensor was heated, and internally it bled 12V to the sensor wire forcing it to go rich. New O2 sensor fixed it!
Excellent coverage - thank you very much - and I especially like how you determined to add some fuel ( brake cleaner) and see if and how the narrow band sensor downstream responded in order to validate the upstream unit.
marcel goralik, i wish i could do that but unfortunatly making video's takes a lot of time. I'm very bussy and some of my video's i had to shoot at night just to share it with you guy's😪. But i'll do as many as i can😁
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This video should be mandatory in auto schools. Well done, Dan!
logical canuck Thanks!👍🤪
ALL Dan's videos should be in auto schools. You are the best Dan!
Fully agreed
I had to diagnose a stalling problem on a 95 Stratus 3.5. Long story short fuel trim max high bank 1 and then max lean on bank 2. When reset it would run for a few minutes until the trims would do it again but sometimes swap sides. Long story short the engine had been swapped with 1 year newer and bank 1 & 2 were reversed in the harness on that year model. Computer would see bank 1 go lean and enrich bank 2, bank 2 seen rich and lean bank 1 some more. That was a fun one.
They are in my classes. Willcox, AZ High School
Hey Dan I know this video is a couple of years old but it just saved me over $2000 dollars. 2006 Acura TL 216,000 miles P0420 catalyst below threshold bank 1. But short term and long term fuel trimmed maxed out. Downstream sensors were reading lean condition.Sprayed carb cleaner to verify downstream o2 sensors were working. They were. Long story short coolant temp sensor was +40° off. Making the ECU think the car was hotter than it was and giving less fuel. Which the o2 sensors were reading and ecu trying to compensate with fuel trim. No 02 sensor replacement ($200 × 4) no catalytic converter replacement ($600 ×2). I do my own work (free). $30 coolant temp sensor fixed everything. Cant thank you enough. If you're ever in NYC I owe you a ton of beers.
Was the temp sensor reading off by looking at the scan tool live data? Or how did you find out the temp sensor was bad?
I cannot think of another skilled trade where we are required to have such vast knowledge yet earn such poor pay.
Within time constraints and owning/needing costly tooling/equipment as well.
Not to mention the safety risk and health effects. My shop refused to provide us with safety glasses, mask, ear plugs or knee pads. They provide a cheap safety shoe once a year so if you worn it out, they wont replace it for you. The gloves they gave are cheap cloth ones, not oil resistant nitrile. Used engine oil causes cancer
Poor pay? My tuner charger me 1100 for 4 hours of dyno tuning. Y'all charge 80 to 120 per hour for labor. How's that poor pay? I was a mechanic for the army for 14 years. It's not hard labor. And tuning requires knowledge. But that's it.
@@09fatbobmike We probably get $11 - $25 per hour from that 80 - 100
@@bengkelbawahpokok6753 WELL thats some shitty shit there. time to start your own business. 25 is good but anything under 16 is under paid.
You are teaching the whole Earth Mr.
Your teachings are better than those at the University
Best automotive teacher I've ever seen.
this dude is smart he knows how to explain things simple to understand!
My wife thinks I'm dumb🤣🤣
@@Diagnosedan Great thanks to your wife, otherwise we never know if you would try to prove yourself opposite by explaining us thinks in such an excellent way. So, when she says so, let's think this is the way how she develops your talent.
Are you familiar with nissan tiida latio
@@Diagnosedan all wifes are the same.
Women, they hate each other, and they're partners/husbands (after a while..) because we share and admit the clever among us, while them/they're, nothing like that.. brotherhood of man.
And I swear I am not misogin..
@@Diagnosedan 😂 I know how that goes!
Now in my sixties and having left the auto technician career behind (25 years ago) for tool and die, I'm thinking of a return. Of course it'll be my own shop. Who would hire an old guy? With your ability to explain various systems you've brought back my mojo. I totally understand you. Thank you for these videos. You are an inspiration.
We have a lifelong respect for a teacher like you. God bless you.
Thank you👍
Me to grate respect
I am watching this video over and over again. Amazingly that other shop replaced a common part that would affect both banks (the MAF sensor) when the vehicle only had an issue with bank 1. Too many parts replacers out there in the industry without "diagnostic" skills. I see it as "keep on throwing parts at the vehicle till the problem goes away"...sorry, but not on my wallet. I love these videos!
Thanks for the great comment!
Friend I need help, my bank 1 and bank 3 are at -17%, do you think it's the MAF sensor or the gas pressure regulator?
Awesome video, So many great uses for brake cleaner lol... another way to verify O2 and A/F ratio sensor operation from the driver seat (on vehicles with vacum power brakes) is to pump the brake pedal rapidly for a few seconds, this will force the system lean and when you stop pumping the brake pedal the system will go rich for a little bit. All you have to do is monitor the sensors and see which one is not responding 😊
👍👍😉
Great tip!
And... another way to verify brake-clean💯
Except on our skin
But why not just press the gas instead of using brake cleaner? How is it different?
Just discovered your awesome channel. I guess the answer to your question is the fact that there is no throttle valve on this particular model. That role is taken by the Valvetronic system.
You have been my great teacher,since i started following u up i have improved i lot in my career as auto electricians. I want to say a big thanks to u.
That's a big honor, Thank you!
That BMW uses a Valvtronic system. Basically it can control valve lift electronically which pretty much eliminates the need for a throttle plate and this is the reason there is no vacuum at the manifold because air flow is controlled by controlling valve lift instead of a throttle plate. This system is very similar to what Nissan Calls VVEL (vairable Valve Electronic Lift). It's pretty slick.
Exactly!👍💪
Мu BMW is a valvetronic is a nightmare for repair
@@traqnsavov822 it's not to bad
my is valvetronic TYPE 1 is not very good, you is TYPE2 is good :)
Traqn was my first weekend at the lake at the beach and my friends at the park at my moms t you can not get gym and the people Savov
Your videos explain everything very clearly. No one does it better.
Michaelangelo Ferrari Thanks!😁
That's a James Bond song. Nobody Does It Better. Dan's new name is Bond, James Bond.
You are the better of the diagnostics, God bless you dude!!!
Thanks! 😊
Watching this video 4 years after it came out and im amazed. Dan, thank you for setting this up and explaining all of this simple and very easy to understand!!
Thanks to your videos I learned to look at my data and it helped me to diagnose an 05 Infiniti with a long crank time and lean readings on both o2 sensors. No lean codes were stored and car ran perfect when it started.
Gregory Jones Nice!💪
I have a 2001 330i coming in Friday. While I was servicing the A/C system he was telling me about the problems he has been having with the vehicle. I scanned it and found numerous codes related to the O2 sensors on banks one and two as well as a Number one misfire. I also found a DME fault code. He told me numerous shops have replaced the O2 sensors MAF Sensor and it had a tune-up. He is bringing the vehicle back Friday for a more though diagnostic. I will have a plan of action in place to better diagnose his vehicle's issues. Thank you for a very informative video on the Wideband O2 sensors and fuel trims.
If I had seen your video a while back, you would have saved me many hours of debugging time and research on this topic. Hats off to you sir.
Keep making these videos keep chiseling our brains as technicians! So far you have not lost me because of the thorough explanations!
You see i am not having any such problem on my car, i am not even a mechanic, however i really enjoy your shows. They are informative and nicely presented. You are way better than lots of teachers and some tv shows.
Dude, you are awesome! helped me with Wide band O2 sensors. Clearer than anything else so far.
Christopher Rumfield thanks for the nice comment buddy it's appreciated!
Diagnose Dan, you are the MAN!!! I ran across one of your videos the other day and I am such a fan now. You are exactly what the new generation needs as a common sense back to basics teacher. You are mandatory must watch for my younger crew. Keep doing what you do and we will keep subscribing, watching and spreading the word!!!
Former dealer driveability technician here. Impressive explanation of narrow vs wideband and relationship with fuel trim. You have a new subscriber.
This is the best explanation of the o2 sensors I have seen. Dan you are a great teacher, keep up the fine work.
This is a very good video presented in a methodical manner. To answer your final question about why that engine had pressure in the manifold it is a valvetronic engine. As a former BMW trained technician the initial give away is the bulge in the valve cover. Not sure if you have done a video on that system as this is the first off you videos I have seen
Regards
Ian
Well I didn't know what Valvetronic is since I do not own a BMW car (my last one was a 1995 E36) and my BMW motorcycles do not use that system either. My guess was a MAP sensor only needs a tiny hole to measure pressure (since it is static and not dynamic) and that tiny hole would not allow enough air to enter the engine. But this video is excellent to understand about Fuel Trim (I had no clue about trim)! My friends Porsche 993 is running ultra rich after having the engine out for seals, o-rings and a new dual mass flywheel and clutch. Plus we did the 964 mod to the 993 cams to pin the timing gears to the camshaft (the original 993 gear is a butt fit to the camshaft using a bolt...in my books a no-no). Anyway, I think we will have to do an ECU Drive Cycle / Readiness. Thumbs Up Dan!
Thanks for the great comment buddy it's appreciated
I like watching people like Dan, intelligent ,funny love what he does. I like to help and teach people too, feels so good,, the more we learn the better we get. this world will be better
Watch your videos a lot. You are the best! As a long time shop owner I often use your instruction to help my techs to never forget the basics! Your breakdowns are awesome! Thanks for all you do for our industry!!!
Thank you very much Jimmy👍👍
Zrozumiteľné,jasné vysvetlenie. Dakujem!
A another easy to understand lesson. Thank you for all your sacrifices you made in order to offer these videos to us! I Can't stop watching your videos, they're so contagious! :-)
Thanks for the great comment 👍👍👍
I agree with Ferenc-thanks again "Dan the. man"!!
Brilliant Dr, Dan. Actually, you are answering what would the audience ask u. Thanks again
Great info, the illustrations really help to understand what is happening
Pico Boo, Thanx😀!
Dan I’m impressed,best easiest to understand description of narrow and wide band sensors I’ve seen so far....Many Thanks 👍🏻
Your welcome Steve👍
You are the real thing. I'm new watching your videos and Im really happy I found your TH-cam channel. Thank you for sharing your knowledge.
HI DAN;
TOTALLY IMPRESSIVE DIAGNOSTICS.
RIGHT TO THE POINT.
YOU ARE A GREAT ASSESTS TO THE AUTOMOTIVE FIELD. THANK YOU
THANK YOU DAN FOR YOUR TIME .... YOU ARE AWSOME TEACHER
Piotr K Thanks for the nice comment buddy it's appreciated!😉
Thanks for making it easier to remember Dan. I always like your videos you are a top notch trainer.
Thanks!😊👍
Every time I have a fieling issue with my bmw i come back to this video, which helps me interpret data from my car. Many thanks for this video
Goed kanaal Dan! Top diagnose technicus aan 't werk, bedankt voor het delen
Graag gedaan, bedankt voor het kijken!👍👍
I have a Commodore with a Buick derived engine. { Australia) I will stick with its simplicity compared to these Euro engines with multiple O2 sensors and variable valve timing. So far 280,000 kilometres and still on original injectors and sensors. I can do a lot of the work myself unlike these complex cars which need some expensive equipment to diagnose. Still very fascinating learning how all this new fangled stuff works. Really appreciate your time and dedication producing this training grade series.
Great video, Dan. I'm a long-time self-taught garage mechanic working mostly on German cars, especially on BMW's. And I'm also learning even more by just watching this video. To answer your bonus question, I think there is still a slight vacuum after you remove the MAP sensor, or else, this Naturally Aspired combustion simply won't work. And the reason that even when you articulate an artificial leak in the intake manifold and still maintained a stoich condition is because of BMW's VALVETRONIC system in place. Under the VALVETRONIC system, the throttle body no longer plays a key role in intake air control. In fact, you can have the throttle body fully open the whole time and it won't make a difference as long as the O2 sensors are properly working and nothing being wrong with the fuel supply. Actual fine control of the air is done by the intake cams which is fully modulated by the VALVETRONIC system.
Hey Pete spot on man!
Also, our after cat 02 sensors do influence mixture on BMW’s by providing a reference point.
Correct Sir
You have that ability to explain complicated things in an easy way...great job danny, btw i've scrolled down almost all the comments and haven't found the ansewer...
Outstanding Dan! even mechanics can learn from this, Extremely well done.
Thanks Bill.
my friend, you are right, in engines with valvetronic there is no vacuum in the intake manifold, one way to create vacuum would be to disconnect the valvetronic motor to force the system to work with the throttle body in this way, the throttle valve now will be closed, and there will be vacuum in the intake manifold. I read you Dan 👍🏽 from Peru
Excellent case study my friend. Thank you for your time to bring these video to us. Cheeers
Thanks! and thank you for doing the same👍
I have been driving myself insane troubleshooting a failed smog on my 98 boxster. Fuel trim negative, indicating rich. But downstream shows 0.1 or 0.05, lean. This video explained clearly that it's likely an upstream. Untill now I have been watching voltage instead. Thanks for the help.
Hi Dan, great videos. My car has a sudden 20% increase in fuel consumption, but no other noticeable changes or codes. This is more noticeable when the engine is cold, but still higher than normal at operating temp. My long term fuel trim stays between 5.5 and 10.9 (normally the low is 8%, it only takes very short dips to 5.5), and short term stays between -2.5 and 1.5.
I think I have a lazy o2 sensor - the manual recommended it to be changed 20,000 km ago. Upstream is wideband, LAMBDA normally stays at 1 while cruising, but sometimes bounces between .9 and 1.1. It will spike to 2 when throttle goes from high to close. mA normally is around 0.7, but will spike to 3.2 when throttle goes from high to close just like LAMBA. Downstream is regular o2, when car is warming up it stays low around .005. It climbs as engine is warming and then stays around 0.7 while idle and bounces between .1 and .9 while driving.
I have no signs of a bad catalytic converter, so should I just replace both sensors?
Well I'm not a fan of just replacing parts. The numbers your giving me ain't great but not to bad either. See if the fuel trims improve with higher Rpm's. Also check your temperature sensors!
@@Diagnosedan Will do! I really appreciate the response, you're amazing!
@@Diagnosedan Hey, I forgot to come back to tell you! I started monitoring my coolant temp and noticed it always stayed between 170-185 when warm without any symptoms of an open thermostat. I pulled the temp sensor and it was covered in a film. Changed it out for $5 and my car is running great again! You da man Dan!
Very informative... After replacing my injectors, I started noticing backfiring.. I never thought a lean condition could cause that.... Your video has inspired me to send the injectors off to be tested and after I replace them, I'll check my O2 sensors. Thank you
Smashing video once again Dan. This test can also be used to diagnose a fuel injector fault! Running lean and both o2 sensor working ok but engine runs better adding brake cleaner means injector fault. Watching the smooth running values on these engines also helps understand the cylinders which aren't performing well, positive numbers indicate less mechanical output of the cylinder.
Dont forget on most newer BMW and mini deleting codes doesn't reset the fuel trim adaptations or injector learnt values etc , so you may change faulty parts and car still runs bad with learnt values which are incorrect. Injectors for all gdi engines must be coded.
Always wondered what the Injector Coding function on scan tools did. Thanks.
Awesome video thank you Dan the man . System bmw came out with I believe it’s called vanos which requires no throttle plate so that engine rpm is changed through variable valve lift
Thanks for the great videos,sharing them with the younger techs on my team to sharpen their skills
That's great! Thanks for sharing!
I watch your video as a good series. Not every educational institution explains so well. As they say there are no bad students, there is a bad teacher.
Hi Dan great video,that bmw engine has no vacuum in manifold because it,s throttled by valve lift not throttle butterfly.
Martin Bates, right answer!🎯
This helped me understand why my Narrowband replacement o2 sensors weren't working... my car was designed for Wideband sensors! Thanks!
13:36 Because the engine has a valvatronic system, which replaces the operation of the throttle valve, and instead of it, the valves open at a certain height, and not the throttle valve. And the typical pressure in the intake manifold is close to 950 millibars normal atmospheric pressure is 1013 millibars.
Typical vacuum in most naturally aspirated engines is 300...350 millibars.
Well done! Even a non-carmechanic like me totaly understood your story. Thnx
Great content in this video! I am surprised that BMW does not have a back up fuel strategy for circumstances like this, a lot of the Asian vehicles use downstream fuel trims when they have a upstream wideband
Eddie, Thank's for your feedback!😎
Learn so much from you in the span of 6 mins and learn that my upstream 02s is needing replacing thank you!
A quick question Dan, can you tell a narrow band from a wide band just by looking at them. Just watched this video of yours for the 4th time. Brilliantly explained. I’ve even shared it with my work colleagues. You’ve even started a catch phrase in my garage. When I fix something I turn to the other guys and say “ diagnose Paul fixed it again”🤣
Ha ha thats awsome! Narrowband sensors usually have 4 wires and wideband sensors usually have more. If you follow this rule your right 95% of the time😉 Thanks for the comment DiagnosePaul💪
My name is also Paul, thou I'm the only one in my workshop I also can say this out loud just to boost my self 👍👍
Awesome video as always Dan , was at work today working on vehicle with wide band sensor , it’s never too late to
Learn more 👍
Awesome as always dear Dan .You need to make an encyclopedia or a method for mechanical schools .
Ha ha i'm bussy enough already
Best short/long term fuel trims explanation video. It had to be a Dutch guy. Mooie!
Very good video Dan! Always a pleasure watching them.
Alin Marinescu Thank you!😉
Fuel trim was always a problem for me to understand before i watch this video. Thankyou v much
Just discovered you and glad I did you're a great teacher!!!
Great to have you here!
You are the King of diagnoses 🙌, I learn so much from you😎
Really sir thank you for your sharing information it's help me to fix mercedes s class
Jaddah Auto Repair Electrican , Technician that's Great!😁
You are a great teacher Dan!👍🏼 thank you!
If I’m not mistaken that BMW also have an absolute pressure sensor in the intake manifold, which will not sense an intake air leak.
No vacuum because Bmw uses valvetronic so the throttle is open 100% so no vacuum.
100% right, not bad for a volvo tech😉
@@damarihector9566 You hacked Cameron Tony's girlfriend's Instagram too?
The throttle valve is used for start up and shut down other then that the valve Trinidad system varies valve lift to near 2mm at idle and controls volumetric intake during so and upon hard torque demand the lift is increased as needed
Valve tronic
This video is so good that I watch it over and over again.
Excellent explanation ,I now understand how it works. Is there a quick and easy way to identify which type of sensor we are testing? I assume that a wide band sensor has more wires than a narrow band sensor but is there anything else to look out for identification? Just found one of your previous answers to the same question, should have read further. Thanks for a brilliant video.
More wires and O2 current in scandata
So can a four wire be a wideband sensor or only from five wire upwards are wideband sensor?
Is there a possibly to know without having a scan tool?
One comment. It would make things a little clearer if you also explained that the fuel trims only/primarily react to the upstream sensor and not the downstream sensor, otherwise one of the best case studies I have seen. Thanks
No throttle plate... variable valve lift is used to regulate air flow. If I remember correctly. =)
Thomas EXOVCDS darn, you beat me to it😋
Pico Boo But you've probably worked on / serviced one before... I only recently found out about this witchcraft!
Thomas you're right!
There is a throttle plate b.t.w but it is only used for backup, in case the valvetronic fails😁
Is it the Prince engine? Also used on some Peugeot cars?
Jonathan Dean, as far as i know peugeot doesn't use straight six engines.
I just got an 08 Sienna in here. Wide band sensor. Misfires on one bank. This video is so helpful. Fake Diagnose Bill is going to TRY to fix it again with COOL REAL Diagnose Dans help.
You are the one and only DiagnoseBill .
Great video Dan 👍 very well explained.
Simply Diagnostics, Thanks Steve! Watching Diagnosedan video's on the early morning🤣. I woke up watching Leons carbon clean video!💪
Awesome and very clear explanation! It was like I was in school! Subscribed!
Also I was wondering who has answers on that last one, why the non-turbocharged BMW has positive air pressure on idle and not vacuum?
Bro! You going to be famous in the hole world you're awesome
🤣🤣
Very clear explanation and great video! Where does one learn this level of knowledge. You inspire me to want to learn.
Very informative and well done video! Thank you, Dan!
Dan - you killed it ! So clear and concise. Grateful you took the time to post this. Really helped explain the P0172 I had on my Subaru Forester.
Very good info Dan, thanks for sharing.
Nice to hear from you Maic!
Well put Dan, very easy to follow your explanations.
Thanks Dan
thumbs up, great job Dan!
Thank's Glen😜
You seem to have a better understanding about this topic than most. Please help me. I recently installed long tube headers in my car, with catalytic converters. Following common practice, I also installed sensor spacers. This eliminated the P0420 and P0430 codes, but I'm now getting P2096 and P2098 codes consistently. The car is a 2018 Mustang GT. The headers are 1 7/8 inches going to a true 3" cat-back exhaust. As I'm sure you know, the pre-cat oxygen sensors are wide band, and the post-cat sensors are narrow band. The car has an aftermarket tune. It runs well, and the air/fuel mixture hovers around 14 (I assume it's lower than 14.7 because of the 10% ethanol, 91 octane gas I'm running), and the tuner probably made it a bit rich. My mechanic confirms there are no exhaust manifold, exhaust, or unmetered air leaks. The tuner won't turn off the post-cat sensors, which is understandable. Questions: can you confirm that P2096 and P2096 actually indicate that the mixture is too rich (rather than lean), because the bigger exhaust is throwing off the post-cat oxygen sensors? Second, if this is the case, is it ok to continue to drive like this, occasionally clearing the CELs? Please help.
I like the learning videos best, like this
Jackie Chan Thanks!👍
Thankyou. Your explanation is very clear compare to my instructor
Interesting post indeed, thanks for sharing!
Lito Blanco Thanks for watching!😁
Hey Dan
Thanks for posting these videos your are a great teacher. I have been watching your videos for a little while now and I have learnt alot. I have been applying your technical advice in the field and using scopes more often than I use too. I try keep it simple and not be a part changer thanks to you and several out their I am becoming better and enjoying diagnosis more. I will try to to pass the torch. Of knowledge to our fellow technicians out there as you are. Thanks again.
For the answer to question for no vacuum on bmw its due to the valve tronics it act like the throttle and the actual throttle stays open all the time which does not allow negative pressure (vacuum). Bmw actually installed a vacuum pump driven by engine camshaft. I think when system goes on fail safe throttle may operate like a normal throttle open and closing not sure correct me if I am wrong. Anyway keep up these great videos and I will keep watching. Your awesome
Keep them coming , very very informative..thanks Dan
No problem!
It's interesting... Always new guys need learn old knowledge. I have tried to figure out how this works for a couple of weeks, and even though I have looked at this video sometimes, I have forgot it and the video.
But now I have to copy the whiteboard information into my notebook! 😁
Maybe I then can get more information from the data shown in certain apps, otherwise we have to improve the apps. How difficult can that be?
Dan, you are an angel, or you was also five years ago. One difference, you looked somewhat younger five years ago... 🥺
That's how it's done ✅
The Homie Hektor
Thanx for the great comment!😁
Well done explanation I will be showing this to my auto class tomorrow
Great! Thanks Dusty
It's a valvetronic system. Throttle plate wide open and valve lift regulating air flow.
Bullseye👍💪
i can't understand,, would you explain it, please?
@@fitrimaryandhi9105 The BMW valvetronic system uses not only variable valve timing but also can vary the lift of the valves from less than 1mm at idle to several mm under full acceleration ( Don't know exact specs). Under normal operation the throttle plate stays 100% open and air flow is controlled by varying the valve lift in response to driver demands.
This reminds me of the time I had to diagnose a 1990 Dodge pickup with V8 and automatic. When cold and warming up, ran great. Once it reached operating temperature, it would chuff and chug and misbehave. The single O2 sensor was heated, and internally it bled 12V to the sensor wire forcing it to go rich. New O2 sensor fixed it!
Absolutely awesome video awesome channel and an awesome guy
bodgit and leggit garage , Great comment. Fantastic to hear these things comming from a pro like you! Thanks Leon! 👍👍👍👍
DiagnoseDan 😘😘😘😘
The best video demo on O2 sensors.
Trying to comprehend these fuel systems and these sensors function,are quite difficult.....thanks
Don't overcomplicate things, we don't need to build them but just diagnose them😊👍
Excellent coverage - thank you very much - and I especially like how you determined to add some fuel ( brake cleaner) and see if and how the narrow band sensor downstream responded in order to validate the upstream unit.
how about 1 video a week? We need to now more and more about them. PLEASE!!!?
marcel goralik, i wish i could do that but unfortunatly making video's takes a lot of time. I'm very bussy and some of my video's i had to shoot at night just to share it with you guy's😪.
But i'll do as many as i can😁
We all lookink forward for them. good job we have YOU anyway