Chevy Tahoe 5.7 - Misfire & High Idle Complaint
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- เผยแพร่เมื่อ 7 ก.ค. 2018
- In this video we have a look at a Chevy Tahoe that came in with a customer complaint of high idle and misfire after the vehicle warms up. The customer already replaced TPS, IAC motor and spark plugs. After a little poking we nail down this diag and find out what is causing the problem. -Enjoy!
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I know this comment doesn't have much to do with the actual repair but there is a lot to be said about you Eric O for always trying to remain professional even when people bring you to your wit's end. I've always respected you for never bad mouthing customers and remaining civil when dealing with others. It's so easy to start swearing and speaking poorly of others but rather shows a man's true class that he doesn't allow his emotions to puke out his mouth uncontrollably. I myself always present myself as a professional, even when I have mixed feelings about others. Some people don't realize that your credibility suffers when you project an immature attitude. For you personally, your actions only enforce to me that you are a truly top-notch human being. SMA number 1 auto repair channel on TH-cam. Period.
Yep the SMA cool head approach even when fatigued and under duress is what sets him apart.
Always a civil approach to all and effort of courtesy and some humour .
Couldn't agree more.
You could tell he had a long day but still made time to walk us through the diagnosis. He was talking faster than normal to shave off some time.
Mr B h
If only his wife could be happy with his success, have you seen her hate face? lol Jealous much.
Free Tip Sunday. Once you see the smoke pluming out, if you turn down the flow rate of the smoke until it just dribbles out of the leak you can see exactly where it's coming from better. Something Mark Warren teaches in his Evap classes.
Another guy mentioned that. This is the 1st smoke machine I have had with a flow gauge. I will have to remember to use that feature more.
How much is a smoke machine
@Hector Cortez-aponte-cabrera Yes. It's just a tip to help diagnose a problem. Eric O wanted to get a clearer look at *exactly* where the smoke was coming from.
Guessing can come back to bite you, or just result in wasting your own time.
He just needs to remember that feature next time :\
I was saying check the Spark Plug for cracks! Then you swapped it with number 2 so ruled that out immediately! 'Smoke Guy' is gonna see all that smoke coming out the doors & come back! Keep your chin up BIG O!✌️
On a weekend having a bad day and your still a great positive person. Thanks!
Thanks for all your videos! They give me confidence again being a Diesel Mechanic by going back to basics and not over thinking! And found a ground wire broken on my 05 Colorado for the MAP Sensor. Thanks again for your knowledge!
I really don't watch other TH-cam videos until the very end (except VetRanch!), the time spent enjoying your diagnoses passes so quickly! Thanks for keeping us educated even when it's time to go home and get more sage advice from the kiddo.
Low Voltage is problematic for any computer controlled vehicle with many modules. I got up this morning and saw a case study misfire and tps issue on my alerts from SMA and I was happy. I cannot get enough of Eric's video's. He is thorough and knows what he is doing. I am learning alot from SMA and have to say his video's are the best on here in my estimation. Thank you again SMA. Thumbs Up.
This type of problem-solving mystery where viewers get to play along while watching is really interesting and very engaging. It's a lot of fun trying to figure out the problem before you do, and I believe it results in much greater knowledge retention vs just a straight tutorial video about how to fix a specific problem.
Really valuable content - thanks for putting it together!
"Here smell that" - my favorite thing that's ever happened in a TH-cam video
I tried at first but then I realized I couldn't. Ha Ha. Gonna have to get a better up to date computer.
I love the smell of gear oil in the morning.
I swear now that I'm back on east coast I'm willing to, if my truck will make it, to bring it up to SMA to get worked on. Love how thorough and honest you are with diagnosis. Discovered you back when I lived in texas. My old 98 Chevy made the drive to the east coast but picked up some issues on the way. Need her running like new again
Single cylinder miss was a bit of a red herring...A systems approach is always best.
Well done Eric.
Your scientific and methodical approach is to be admired. You always get to the root cause.
I swear, Eric, when you stuck that plug under my nose I could smell the gear oil! Well done!
I find your videos fascinating. I enjoy your talking throughout your process of elimination. Well done videos.
I am impressed by your methodic aproach. Loved listening and following your every moves. You explain things so well. In todays auto world you need to know about full diagnostics before cranking on a wrench!
I subscribed!!
God Bless.
You are probably the most talented mechanic I've seen on youtube. Your videos are part of the reason I wanted to go to automotive tech school. Thanks for the content and keep up the great work.
I watched a mechanic rebuild carbs one time (an older Honda) and spent 1/2 a day and not fix anything. He finally did the basics and found low compression on one cylinder. If he'd done that first he'd saved a lot of time. You are correct in checking fuel, spark and compression first. Eliminate the basics!!
that smoke machine sure made a definitive diagnosis . i usually do the "down and dirty" brake clean with the straw spray as well. you are thorough every time. i would hate finding the problem and not being able to fix it....it would be like cranking the "jack in the box" right until it is ready to pop out and stopping right before every time!!! and thats no bueno!!!!!!
My last truck was a 96 GMC with the 5.7 vortec. They used crappy neoprene gaskets. I replaced it OEM once. Then later on (100 K or so) I replaced it with the Fel-pro gasket. Steel and rubber. Sold it at 190K in 2010. Several friends that had the same year truck. They ended replacing them as well. That gasket dried and cracked. Good truck though. Wish I'd have just kept that truck and bought a another Motorcycle. I ended up with a 08 GMC. Also has been a great truck and currently at 170....
Finally, a good video using smoke. I don't have the fancy scan tools but I get a lot of information through the logical approach you use.
Incredible Mr. O....Reality diagnostics, Humble attitude, True to Life. Always appreciate your Service and Inputs...That guy over on 'Schrodinger's Box' needs to pay attention to you!...He's stuck on himself for a 2 percenter. Ridicules others. Your personality is appreciated! Is just one reason you have a Fantastic Wife! Thanks.
thank you! i have replaced everything on my tahoe. was about to give up until i found this video. exactly what my tahoe is doing.
Your videos are just excellent. Well made, edited and easy to understand. I have a '99 5.7 Tahoe, so many of your vids relate to my car and teach me many interesting subjects.
I for one appreciate the thorough diagnosis. I've been burned by rushing through diagnoses before.
I have this exact truck and have experienced the intake manifold leak twice and a failed injector poppet once which caused a hard miss. Both times the intake leaked, I had coolant loss. Great video as usual!
Hey man I see no reason for me to complain about how or why you do your experiments no matter how I would do it I always learn something new from watching you solve the problem’s. Your an inspiration to me and I’m sure many others stay with it many thanks for sharing your experience and tips and time with helping us out with hard to solve issues working on cars and trucks. Thanks Again Glynn Higgins (obion tn)
Your like the Sherlock Holmes of troubleshooting. Your teaching this old dog a few new things. Appreciate your sharing of. Knowledge
Thanks for sharing your knowledge. Great step by step diagnosis
Sorry you had a rough day sir. Lot's of good tips and diagnostic direction info in this one. Thanks Dr. O!
I once had a lean code on bank one and two..turned out it was the intake manifold gaskets because of how horrific my gas milage was..and noticed how it ran in cold and or at temp..I did the job myself and purchased fel-pro and never came back..thanks to you bud!! Appreciate the awesome work.
Bled many brakes over the years wish I knew that digital bleed technique. Another great tip from. SMA. Thanks Eric
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Good job Eric! That was a interesting problem for sure!
You’re human and some days our patience is less than others. Again good job on that diagnosis and thanks for the video!
Oh I forgot to thank you for your last video. It helped me give my landlord a direction to fix his issue he was having! Good stuff!
Great way to start a Sunday morning!
You're a good man, knowledge, ability and willingness..Thank you.
Very informative I'm having same problem 97 gmc 1500 first video I have found to help me thank you
Every one has bad days but even on your bad day you knock it out of the park I like seeing that some scan tools won’t work all the time and I like the new smoke machine you are doing it well
Smashing diagnostic, your final test with smoke was excellent :-D, i love visual tests.
After the compression test was fine and the injectors tested fine i was clueless.
I was thinking about air leak but highly localised - which would be unusual. Pipe off somewhere local to that intake port area but I am not familiar with that particular beast anyway.
@@exidy2290 The purge valve was right by #4 cylinder. Thinking if it was leaking around the valve it could possibly cause the problem.
Thank you for the helpful tips and taking the time to do these videos.
It is never boring to watch you running data with the scanner. at least for be anyhow! One of my kids is driving my old '99 GMC Yukon with a 5.7. It now has 330 k plus. It's been a good truck.
Kudos for not getting all high and mighty about a DIY'er using what they had for anti-seize - refreshing to see!
New sub, Pirate air, and the bad day video won me over. Fact that I learned several things along the way are a bonus. Good content, look forward to more of your channel.
Having identical issues with my 97 k1500 this video really helped!
Good diag, the one thing I noticed early on was that the commanded RPM was around 600 and the truck was idling around 950, no matter what it did. I was leaning towards intake air leak already at that point. I enjoyed the process you went through to eliminate other potential sources - and the free tip was a bonus!
Good job on narrowing down the problem.
I used that tip same setup you had on a 4.3 worked great !
I love your comment about sorry its amateur hour lol. Good diag procedure, I thought it was gonna be the poppet valve on that cylinder. I got burned on one on a s10 and it ended up be clogged
The owner better let you do it ,he will Jimmy it up for sure.good job Eric
I have that exact same Tahoe in the same color. It’s been so solid and reliable that I just can’t get rid of it. It’s a beast.
Great diagnostic, next time you see the truck, it’ll will be on the hook!
Good Job Eric! Excellent as usual.
Always interest me when you grab another new tool out of the box I'm unfamiliar with. Thanks Eric!
Brilliant video, outstanding teaching! I've figured out how to watch your videos. The way to do it is to pause at each decision point and think about what the next step should be. Of course there are multiple ways to proceed. Some guys would have looked at STFT with open throttle and then to smoke, as I've seen you do in the past. If you did it that way, the video wouldn't have been nearly as interesting or complete.
Its nice to learn the various ways to get to the root cause. You are an excellent teacher. Im surprised you dont teach diagnostics at your local Votech school!
I really enjoy your videos, thanks.
Good work Eric
Love your patience man! I would have thrown many shits with the issues you come across.
Good diag on this one Mr O! Appreciate all the videos lately, thanks for taking the time. Negative comments are just like dog droppings, just don't step in it and keep on walking brother.
Great experience on this one.... vacuum leaks suck!
Congrats 150k subs!!!
Wish I had a shop teacher like you in high school.
Fun Fact: oil is a dielectric insulator. We use everything from hydraulic oil to straight 40 weight motor oil inside of oil filled junction boxes that go underwater offshore.
That’s interesting. Thanks for that tidbit. Cheers!
So water was gonna pour into his spark plug holes? Water protect yes. But needed in truck engine as insulator no.
Kenneth White no, enough gear oil on a plug could insulate it and cause a misfire.
Robert L that's the point I guess I was trying to make. Why would you use that stuff if it could cause problems. Guess different people use different lubricants.
Kenneth White I see, yeah. I just put a dab of copper anti seize on plugs. The lipstick type tubes of it are great.
Another great video Dr.O checking things out before making the call. Until next time PEACE
I have the same issue with my 98 k1500, except that is always #5 that shows a misfire. Many thanks for your video!!!
Have a wonderful weekend Mr.O!!
mikey mike it's Monday! 😅
Thanks for the ride along😊
Hey Eric in the new age of fuel injection I have been screwed also. Port fuel injection vs TBI acts like your run of the mill carb relys on carryover into all of the intake runners. Can see your misconception on the diag. Good catch in the end.
'Pirate Air'........another Eric 'O' sourced piece of info that I can use to bluff my way when talking about diagnosing stuff in the pub. Great video as always. Need to make myself a smoke machine....
That smoke test is genius.
My biggest gripe with the Encore and the reason I hardly ever use it is the loading of data when changing pages in the data stream. I can’t stand how it always has to load data from the page before you can scroll again. Also the countdown after quoting things like special tests. Gear oil is the worst. Especially old gear oil.
Best mechanic on TH-cam
Thank you Eric.
A quick easy test to see if the intake is leaking is to place your hand over the oil fill tube and feel for vacuum, and the pcv opening on the other valve cover. If it sucks, it's gonna suck.
Great Diagnose 👍💪👍
Keep up the Great Work
Great video Eric as always thank you sir!
Interesting, good troubleshooting
That's a really nice job sir I never sow anyone do it this way in my regain of the world
Eric, I had the same problem on 5.7eng but mine was on #5 & was an internal vacuum leak & oil consumption & I pulled the oil fill cap & engine stalled R&R intake gasket! bada bing bada boom!!
We all have bad days. Great job!!
This was a very good video.. Enjoyed watching and learned some new tricks..
While you were pulling data in the beginning of the video I noticed it was only reading 10 inches of vacuum. Reading vacuum can be a very effective diagnostic tool especially when you have a fuel trim issue.
very interesting how you tracked it down. cool vid
I found this very interesting, thanks. I feel like I'm beginning to get a grasp for how a car works lol. Love that term "pirate air". I've got an image of a jumbo jet with a skull and crossbones on the tail fin. Ahoy, Me Heatries! If I fly somewhere I make sure I fly Pirate Air.
Great video thanks for sharing.
Good diagnostic procedure. I would've added one more test before swapping spark plugs though; secondary (or primary) ignition waveform on the suspected lean cylinder. Getting to know ignition waveforms and how they react to fuel delivery in the cylinder (or lack of) can save you a lot of time swapping components in the future. Lean misfires are usually easy to detect on scopes if you know what to look for. The waveform can also answer questions related to compression as well as the plug itself (obviously). Also, positive fuel trims confirmed a lean condition on the bank. Revving up the engine would cause fuel trims to drop when there is an intake leak because the rush of air through the throttle body would make the leak tiny in comparison. Just my two cents. Good job finding the problem!
God i love the smell of gear oil in the morning. The more rancid the better.
Excellent diagnosis Eric. I was feeling a bit lost after the injector balance test. I think i might have done a leak down test to see if it had a valve issue. I've never seen a leaky intake cause such a cylinder specific misfire. Injector pulse tester is a great tool to have. I got mine to diagnose a misfire on a CRV a few years ago and its been pretty useful. Not bad for £29.
Great video ! Very thorough !
Great diag as always
I love his thinking out loud. It shows how he troubleshoots and it teaches people new to cars and working on them the thought process. Mr. O would be good at anything he tried. Yes two of the prerequisites for being good at things. He is willing to try. He thinks.
Thatvwas a interesting video. Thank you for sharing you knowledge and tips and tricks. I have a 98 5.7 that i believe has a couple bad injectors. It doing basically the same thing but the plugs are wet with fuel. Good compression and spark.
Great Video. Maye the guy looking for cigarettes saw you smoke test & thought you were burning one.
Maybe sticking my neck out but some of these horror films it would be interesting to know what was done wrong by the customer and how much it cost to fix. And then a rough estimate on how much required maintenance would have cost to prevent the nightmare.
Great video as usual. The invention of smellovision.
Eric is never tired is a bionic man
Thanks Mr O for taking the time to make these videos even when you’re having a bad day 👍
No need to justify why you took the diagnostic path you took. It all made sense as you were explaining it. You need to start somewhere and we rely on our experiences to choose a path. Good video, good diagnose!
Had wiring going to the spider injectors go bad chased a misfire in customer van for a couple days in-between working on other customers vehicles, power probe was a life saver
The smoke wins again. Nice work
The cigarette guy knows you were lying to him, he saw the smoke from down the block on the corner, lol. Good find Eric!
OMG glad to see another tech have shitty days too. Great videos and hello from Canada! You have a great sense of humor even after a crappy day.
I’ve never heard of anyone using gear oil for spark plugs, that is truly bizarre!
Not so bizzarre. likely be an EP oil.
it worked well enough to still be detectable. must work in a pinch.
I've never put anything on my plugs when I replaced them. I justed used light finger pressure to make sure the threads were seated properly and hand tightened them before I picked up my wrench.
@@tanis143 I was taught to clean the threads. Take a plug out playing the threads, clean the carbon out of the plug, check the gap, reinstall. This is back in the day of leaded gasoline though
Great video Eric thank you