Paul! That MAP sensor wave form is awesome! The amount and length of vacuum drop on the wave does show a valve problem. The #4 drops down to similar levels as the rest but rises slow than the other. I think that is the evidence we need. Thanks for a great video series!
i like relative compression signals to show map signal change which is more drastic in comparison to the others and the drastic change causes the next map event to show up less as the map sensor pressures try to recover from the flood of pressure. amazing what you are doing with electricity.this stuff is life changing when diag time and confidence meet. your premium channel is a must have tool. each time i view a video something always hits me that maybe didnt the first time viewed.
I've watched this case study multiple times and I see more detail each time. Gone are the days of the grease monkey and a good thing it is too. Over here we have heater plugs in diesels that double up as in cylinder pressure sensors
Great video Paul, I have had a blocked drivers side CAT on a F250 V8 petrol, When I put the WPS in the cylinder and the pressure on the exhaust stroke was huge, from memory they got as high as 50 PSI at WOT so you never need to remove the O2 sensor to check the pressure again....
Hi Paul,I've watched all 6 episodes of this and found it very helpful if not somewhat confusing at times lol but really eye opening and very interesting.....Many thanks
Paul, This is really a great tutorial. I enjoyed every minute of the discussion and can't wait for more. I wasn't a fan of scopes, but this is an amazing display of what they can do if you take the time to analyze what you're looking at. This is great stuff! I appreciate your time and tenacity on this problem. Gene
ScannerDanner Premium This is exactly how to expand a student's thought process. Yes, after leak down test we would have pulled the head and repaired the leaky intake valve(s). But, learning different methods and reviewing fundamental engine functions and weaving in and overlaying new testing methods is invaluable. You are giving your students new tools (thought process) that they will never get in the field, and more importantly can give them an edge in a competitive workplace. Great stuff. I can't say enough good things about what you are giving your students and the folks like me watching the videos. Gene
Good stuff as usual. During the power stroke, combustion pressure will also escape through the defective intake valve into the intake manifold. If I understand the pico traces, that increase manifests itself.
Thank you mr.danner it's good to see someone like you sharing you knowledge I know I am learning something. If you don't learn something new everyday then you didn't have a good day
Cheers for the video Paul. I'm pretty sure you can see the leak on the exhaust stroke as well keeping the pressure high. If you use the pressure waveform to give yourself a rough idea were the piston is in the cylinder as a graph it would help to visualize the valve opening time. If I get time ill get a screen grab of your video and post an example. If you remember back I pointed out the pocket on the verus but the detail on that scope didn't really give me confidence.
This a very good class and very well explain. The pressure going negative is a very good observation to show the valve leak. However the best tool would be to have a pressure volume curve calculation but picoscope seems not to have this feature for plotting this type of graph because you need to input several parameters for calculating the volume of the cylinder but it could be done externally by exporting the data and entering the information on a matrix.
Paul awesome. To be honest with you I don't think i aligned with you on previous part, what I thought is what explained in this video. Great man you are proving me that u don't just read theory but would like to expirement theory and make it practical with evidence. I can bet you will go ways up in ur field. Thank you very much and I like to donate ur account. Can u pls message ur account to donate. I feel guilty to watch all ur hardworking without a penny to spare.
I appreciate that, I don't have a way to donate but you can sign up for my premium channel if you would like. I have almost 100 videos up there now. Thanks!
Paul, a fantastic video showing the capabilities of the picoscope. It’s one of those tools that you really need a good teacher that knows how to use it. Your showing lots of potential possibilities and by your own words you don’t know enough on how to use it. Your doing a great job exploring it with your students. I never had this when I was training back in the late 70s so I have no where near the ability to look at this stuff the way you do. I love the channel and the excitement you show teaching these guys. If only all tutors were like you. Ours were to keen to finish the lesson and head to the pub in the uk back then! For more understanding of the scope patterns what book or videos would you advise to buy? This scoping procedure is so interesting but also so confusing at times trying to understand valve events, strokes cycles etc. Do you have more videos explains the full cycle in the scope patterns, explaining in more detail? Keep up the great work!
Thank you for all you contributions on here Just one consideration having done experiments with my pico and in cylinder pressure transducers over the last year or so when you add the in cylinder transducer the volume of the hose from the spark plug hole to the transducer lowers the compression ratio slightly so one often see a lower current draw on the cylinder with the transducer ..John
Good demonstration on using scope to try and figure out this problem. Not much time saved except for relative compression showing which cylinder was at fault. Without the information from the hummer tech would you then also have to remove the valve cover and verify the valve lifter was not allowing the intake valve to completely close. Sorry for more mechanical work needed, before condemning the intake valve. If this were a commercial job and you took it down and did a valve job, you could have the same problem when you were done. These students are going out into the real world. Keep going you are doing a good job.
+david scharringhausen this one wasn't about saving time, at least I don't think I said that, did I? Anyway, yes, you are correct. If I didn't know the seats were an issue, pulling the valve cover would have been a good next step before pulling the head.
would just like to thank your videos. i passed the engine performance a8 ase but not an l1 master mind like u yet. tho... i try and learn 1 thing new everyday about the engine performance field! altho im not in that field
In video 5 you said you will take the readings on the replacement head. It would be interesting to see what the MAP looks like with the re-worked or replaced cylinder head. looking forward to part 7 "The day After".
Hi Paul. Always love your stuff. Regarding the start of this part 6, I think one would need to be careful of studying comparisons on relative compressions by doing an amp probe starter current relative comp test when you also have a pressure transducer in the suspect cylinder. The removal of the spark plug to replace with the pressure transducer increases the TDC cylinder volume and reduces the max compression available on that cylinder so a good cylinder would also be expected to show a max starter current and therefore cyl max pressure reduction. Maybe I'm missing the point at the start of this video but we can identify which cylinder relates to the starter current trace from the ignition pulse but the in cylinder pressure transducer just throws a spanner in the works. Previously you had shown that cyl 4 was only slightly less compression ( but apparently enough to cause misfire) and that was a good comparison because all cylinders were left intact and the same. A starter current cylinder relative compression test when you have altered the suspect cylinder volume is not so useful for diagnosis to identify possible low compression and might draw the wrong conclusions. When we are investigating methods to reliable diagnose compression problems we need to be careful to make true cylinder comparisons. Best regards Brian
The relative compression waveform was added for the sole purpose of identifying when the other cylinders were at TDC. It was not done to ID a low cylinder as was the case earlier in this series. I only pointed out #4 still being low just because we already knew that. Also the Pico has much better detail than the Verus, so that is a factor as well.
Not a fully formulated thought here, haven't even used one yet.. But what about a first look sensor on a pcv hose or oil fill cap if there's ever a suspected crankcase compression leak. Sure there are some variables there would just be curious of the wave form. Btw this has been hugely informative case study. First experience with all of this with a scope. Diagnosing a misfire, inconsistent compression, on a gm 6.2 not one of the deactivating cylinders.
Great case study, definitely will be putting this info to use. I got a 4 channel picoscope/pressure transducer/first look sensor/pico mixmaster last month and i've really been enjoying it (i'm sure that sounds like bragging, i promise i'm not :) ). After using it a bit i found that the rabbit hole is quite deep, i always find myself seeing things and wondering to myself, what in the hell is that lol.
Paul, very nice good job. According to the pressure traducer training I have received on the video 24.44 the first stroke exhaust valve opening looks as is opening way sooner advance the 180 cursor ,did you say this is the known good cylinder ?? than you
nothing wrong with the exhaust valve opening time. This was taken at idle and the waveforms were identical as far as valve timing goes on the #4 and #5 cylinders as shown in an earlier video.
An even better way to "zoom" low-amplitude channels would be to simply to use AC-coupling and set your channel to a higher sensitivity range like 500mV/div instead of 5V/div. This should give you even better vertical resolution too and eliminate the need to bring the waveform back to the middle of the screen all the time since the ~5V offset is eliminated by AC-coupling.
for sure and I did mention that in one of these videos. I chose not to in this case because I wanted the actual values of the signals. not that it helped me to know that in this case, but I just didn't want another thing to think about. Mainly as it related to the MAP. I wanted to be sure the drop in voltage was the intake pull. I am pretty sure AC coupled, the drop in voltage would have still been the pull but I didn't want that question in my mind. Also I learned how to manage the traces better using the vertical zoom, thanks to a tip from one of you guys!
At approx. 51:30 you said that the bigger pocket that is formed at the end of the power stroke is due to compression lost because of the valve problems. I think that if we didn`t know that we have a valve problem, we still woudnt know that the compression lost is due to valves, piston rings, head gasket. Only the pocket itself is not a clue for the vavle.
I watched it again. Going such detail in versus is not a good choice and don't know if possible, second I assume the location of map sensor in intake manifold is important to rely on map waveform. Am I correct in assuming that if map sensor is located on one bank end it have no way of knowing pressure pulses of other bank.
yes I'm on both Paul,good to see you experimenting with the in-cylinder pressure transducer technique, do you have a FLS (?) it would have been nice to see it on the inlet manifold along side of the WPS in cyl #4 or in fact the PV350 too :)
Great video Mr Paul. but my gut feeling says may be improperly adjusted tappet on intake valve or eroded cam profile. any way in both cases it not letting the valve seat on the surface any how i may be wrong if so please correct me
Great series! Did you ever post the various waveforms from after the repairs were made? I'm specifically interested in the post repair MAP sensor and in cylinder pressure waveforms to compare.
Paul, If it wasn't for the map sensor or vacuum waveform to compare with the pressure transducer, how would you identify that the valve is leaking on that pressure transducer waveform? Thanks
All of this is still new to me bro. But I think a device called a "first look sensor" would be in order. It takes vacuum and psi pulses and creates a signal you can plot on a scope
without looking back were the towers leaning on the leaking cylinder ? Also just to point out when using a sensor ground make sure it isn't a 'floating' one !
No, the towers looked identical. Good point about the floating grounds! Thanks Robski. I recognize your name from either the Pico forum or Autonerdz. Anyway I really appreciate your input
I have a question why would it be a dead hole on that cylinder on relative compression test on the mustard looking color n yet you have almost 155 psi compression?
Hey Scanner, this is way cool. I was wondering, for the engines where the MAP sensor monitor's only one side of the engine, if there might be benefit to putting a WPS 500 into the O2 Sensor and restricting the exhaust to get a better reading while cranking only? And of course putting one in the suspect cylinders spark plug hole so you could still see if the intake wasn't holding? In this test, if the exhaust valve was not seating properly the WPS 500 in the cylinder would have read much lower while the Map sensor stayed consistent I suppose? I do get the reason behind all this. You literally can't get to things on cars now days like you could in the good old days. Thanks for taking the time man.
The scope is the most exciting thing I've seen since the cell phone came out. I can't believe I've only known about them for a short time. I first saw a Vantage Pro 5 or 6 months ago. on Shrodengers box TH-cam channel titled - Intro to Oscilloscope- with a DVOM. His main point was that a multimeter does not sample fast enough to catch some signals. I'm fixing to get a pico scope after watching some of your vids. I'm really impressed with it and want to learn more about diagnostics. Hopefully I can switch my job to diagnostics sometime in the near future.
So, Paul, when the intake valve first opens the exhaust valve is still open due to overlap and when the piston is 90 degrees ATDC the stroke is moving at it's highest velocity and then the lowest pressure will occur. How is that repair coming? Who is doing the work?
+ScannerDanner Thanks chief. Amazing how something that small doesn't look like much to the layperson but can make a big difference. I got a suburban right now that you would just love. Comes in under fairly easy to diagnose. I am thinking about making a "Carnage" video series because that seems to be what comes my way. lol In particular I think a triggering factor to its present condition is a possible backfire through a burnt intake valve. That was the main reason I wanted to see the video pictures. Once verified I would like him to see what such a problem can look like. Thanks for all the awesome videos. I'd watch all of them if I could.
Y'all are gonna put a whole motor in this thing for a head problem?!?! I'd have figured you'd have took it over to Cap's class and had them put a head on it.
You did not detect the intake valve leak on your pressure waveforms because during the tests, valve leak was minimal owing to a lower cylinder pressure (No combustion was taking place, you removed spark plugs). Try in-cylinder pressure test on a twin-spark car (twin spark plugs), ignition enabled, one plug removed and you would see any valve leakage hopefully. I think Alfa Romeo had built such cars.
+Syed Imran Shah I was able to detect the valve leak in the pressure waveform, I just didn't know it at first. It was shown in the weak vacuum pocket during the "expansion stroke". I'm not sure which part I discussed this. Thanks!
I don’t know if you’ll get this or not Paul but I’ve just watched the series and just finished your part six here. And I was really interested to see that expansion pocket difference and I am trying to understand it in my mind. And you just said a week vacuum pocket, but it looks like a stronger one to me?... And have you done any more of these studies recently? Thanks again for all you do! Doug.
i will be waiting for the V configuration engine one with the single CAT restriction, it should be very intersting to.Or maybe stick a banana on the exhaust so we can get it faster,haha!
Great video. Why are you replacing the entire engine to fix a leaky valve? Why not lap/hone the valve seats & valves, or replace the head? I'm not a fan of scopes that are tied to a computer like the pico, at least not for long term use. You are married to that computers operating system and it's hardware. I have an oooold PC I keep around solely for a scanner I have because it requires windows 95 and a serial port. Stand alone scanners and scopes don't have this problem. Plus most decent oscilloscopes have much better resolution then even the most expensive pico. Just my 0 cents (after taxes).
Paul! That MAP sensor wave form is awesome! The amount and length of vacuum drop on the wave does show a valve problem. The #4 drops down to similar levels as the rest but rises slow than the other. I think that is the evidence we need. Thanks for a great video series!
i like relative compression signals to show map signal change which is more drastic in comparison to the others and the drastic change causes the next map event to show up less as the map sensor pressures try to recover from the flood of pressure. amazing what you are doing with electricity.this stuff is life changing when diag time and confidence meet. your premium channel is a must have tool. each time i view a video something always hits me that maybe didnt the first time viewed.
I've watched this case study multiple times and I see more detail each time. Gone are the days of the grease monkey and a good thing it is too. Over here we have heater plugs in diesels that double up as in cylinder pressure sensors
Great video Paul, I have had a blocked drivers side CAT on a F250 V8 petrol, When I put the WPS in the cylinder and the pressure on the exhaust stroke was huge, from memory they got as high as 50 PSI at WOT so you never need to remove the O2 sensor to check the pressure again....
Hi Paul,I've watched all 6 episodes of this and found it very helpful if not somewhat confusing at times lol but really eye opening and very interesting.....Many thanks
Paul, This is really a great tutorial. I enjoyed every minute of the discussion and can't wait for more. I wasn't a fan of scopes, but this is an amazing display of what they can do if you take the time to analyze what you're looking at. This is great stuff! I appreciate your time and tenacity on this problem.
Gene
cool man thanks! I know this was overkill for some but for me and others like you, this is how we really learn, isn't it?
ScannerDanner Premium This is exactly how to expand a student's thought process. Yes, after leak down test we would have pulled the head and repaired the leaky intake valve(s). But, learning different methods and reviewing fundamental engine functions and weaving in and overlaying new testing methods is invaluable. You are giving your students new tools (thought process) that they will never get in the field, and more importantly can give them an edge in a competitive workplace. Great stuff. I can't say enough good things about what you are giving your students and the folks like me watching the videos.
Gene
Good stuff as usual. During the power stroke, combustion pressure will also escape through the defective intake valve into the intake manifold. If I understand the pico traces, that increase manifests itself.
Thank you mr.danner it's good to see someone like you sharing you knowledge I know I am learning something. If you don't learn something new everyday then you didn't have a good day
I bought a Pico, You sold me on it. Thank you for all your help.
Cheers for the video Paul. I'm pretty sure you can see the leak on the exhaust stroke as well keeping the pressure high. If you use the pressure waveform to give yourself a rough idea were the piston is in the cylinder as a graph it would help to visualize the valve opening time. If I get time ill get a screen grab of your video and post an example. If you remember back I pointed out the pocket on the verus but the detail on that scope didn't really give me confidence.
SUBSTANTIAL Sir ScannerDanner
Great tutorial video Brilliant thank you
Sir ScannerDanner
From Nick Ayivor from London England UK 🇬🇧
This a very good class and very well explain. The pressure going negative is a very good observation to show the valve leak. However the best tool would be to have a pressure volume curve calculation but picoscope seems not to have this feature for plotting this type of graph because you need to input several parameters for calculating the volume of the cylinder but it could be done externally by exporting the data and entering the information on a matrix.
Paul awesome. To be honest with you I don't think i aligned with you on previous part, what I thought is what explained in this video. Great man you are proving me that u don't just read theory but would like to expirement theory and make it practical with evidence. I can bet you will go ways up in ur field. Thank you very much and I like to donate ur account. Can u pls message ur account to donate. I feel guilty to watch all ur hardworking without a penny to spare.
I appreciate that, I don't have a way to donate but you can sign up for my premium channel if you would like.
I have almost 100 videos up there now.
Thanks!
Paul, a fantastic video showing the capabilities of the picoscope. It’s one of those tools that you really need a good teacher that knows how to use it. Your showing lots of potential possibilities and by your own words you don’t know enough on how to use it. Your doing a great job exploring it with your students.
I never had this when I was training back in the late 70s so I have no where near the ability to look at this stuff the way you do. I love the channel and the excitement you show teaching these guys. If only all tutors were like you. Ours were to keen to finish the lesson and head to the pub in the uk back then! For more understanding of the scope patterns what book or videos would you advise to buy? This scoping procedure is so interesting but also so confusing at times trying to understand valve events, strokes cycles etc. Do you have more videos explains the full cycle in the scope patterns, explaining in more detail?
Keep up the great work!
this video pushes all the current limits of the modern Auto diagnostics
Thank you for all you contributions on here
Just one consideration having done experiments with my pico and in cylinder pressure transducers over the last year or so when you add the in cylinder transducer the volume of the hose from the spark plug hole to the transducer lowers the compression ratio slightly so one often see a lower current draw on the cylinder with the transducer ..John
yet another variable, thanks! great tip and that totally makes sense.
Good demonstration on using scope to try and figure out this problem. Not much time saved except for relative compression showing which cylinder was at fault. Without the information from the hummer tech would you then also have to remove the valve cover and verify the valve lifter was not allowing the intake valve to completely close. Sorry for more mechanical work needed, before condemning the intake valve. If this were a commercial job and you took it down and did a valve job, you could have the same problem when you were done. These students are going out into the real world. Keep going you are doing a good job.
+david scharringhausen this one wasn't about saving time, at least I don't think I said that, did I? Anyway, yes, you are correct. If I didn't know the seats were an issue, pulling the valve cover would have been a good next step before pulling the head.
would just like to thank your videos. i passed the engine performance a8 ase but not an l1 master mind like u yet. tho... i try and learn 1 thing new everyday about the engine performance field! altho im not in that field
Fantastic video and info , shame customers don't appreciate what we have to learn just so we can fix there car .
Nice 1 paul , thx for spending the time to go into more detail for the same issue, great info on pico useage also :)
In video 5 you said you will take the readings on the replacement head. It would be interesting to see what the MAP looks like with the re-worked or replaced cylinder head. looking forward to part 7 "The day After".
Hi Paul. Always love your stuff. Regarding the start of this part 6, I think one would need to be careful of studying comparisons on relative compressions by doing an amp probe starter current relative comp test when you also have a pressure transducer in the suspect cylinder. The removal of the spark plug to replace with the pressure transducer increases the TDC cylinder volume and reduces the max compression available on that cylinder so a good cylinder would also be expected to show a max starter current and therefore cyl max pressure reduction. Maybe I'm missing the point at the start of this video but we can identify which cylinder relates to the starter current trace from the ignition pulse but the in cylinder pressure transducer just throws a spanner in the works.
Previously you had shown that cyl 4 was only slightly less compression ( but apparently enough to cause misfire) and that was a good comparison because all cylinders were left intact and the same. A starter current cylinder relative compression test when you have altered the suspect cylinder volume is not so useful for diagnosis to identify possible low compression and might draw the wrong conclusions. When we are investigating methods to reliable diagnose compression problems we need to be careful to make true cylinder comparisons. Best regards Brian
The relative compression waveform was added for the sole purpose of identifying when the other cylinders were at TDC. It was not done to ID a low cylinder as was the case earlier in this series. I only pointed out #4 still being low just because we already knew that. Also the Pico has much better detail than the Verus, so that is a factor as well.
Ok Paul thanks for the clarifications
great videos. thanks scannerdanner. im learning how use the scope.
Not a fully formulated thought here, haven't even used one yet.. But what about a first look sensor on a pcv hose or oil fill cap if there's ever a suspected crankcase compression leak. Sure there are some variables there would just be curious of the wave form.
Btw this has been hugely informative case study. First experience with all of this with a scope. Diagnosing a misfire, inconsistent compression, on a gm 6.2 not one of the deactivating cylinders.
Awesome work, thank you so much. Want to see the head off to see the actual problem.
Great case study, definitely will be putting this info to use. I got a 4 channel picoscope/pressure transducer/first look sensor/pico mixmaster last month and i've really been enjoying it (i'm sure that sounds like bragging, i promise i'm not :) ). After using it a bit i found that the rabbit hole is quite deep, i always find myself seeing things and wondering to myself, what in the hell is that lol.
haha yes it is brother
the main concept is to visualize is that the piston and leaking vale are introducing pressure in the intake.thus lowering vacuum.
Paul, very nice good job. According to the pressure traducer training I have received on the video 24.44 the first stroke exhaust valve opening looks as is opening way sooner advance the 180 cursor ,did you say this is the known good cylinder ?? than you
nothing wrong with the exhaust valve opening time. This was taken at idle and the waveforms were identical as far as valve timing goes on the #4 and #5 cylinders as shown in an earlier video.
An even better way to "zoom" low-amplitude channels would be to simply to use AC-coupling and set your channel to a higher sensitivity range like 500mV/div instead of 5V/div. This should give you even better vertical resolution too and eliminate the need to bring the waveform back to the middle of the screen all the time since the ~5V offset is eliminated by AC-coupling.
for sure and I did mention that in one of these videos. I chose not to in this case because I wanted the actual values of the signals. not that it helped me to know that in this case, but I just didn't want another thing to think about. Mainly as it related to the MAP. I wanted to be sure the drop in voltage was the intake pull.
I am pretty sure AC coupled, the drop in voltage would have still been the pull but I didn't want that question in my mind. Also I learned how to manage the traces better using the vertical zoom, thanks to a tip from one of you guys!
the noise on your sync is a freebee showing the EM pulses from the other cylinders.
At approx. 51:30 you said that the bigger pocket that is formed at the end of the power stroke is due to compression lost because of the valve problems. I think that if we didn`t know that we have a valve problem, we still woudnt know that the compression lost is due to valves, piston rings, head gasket. Only the pocket itself is not a clue for the vavle.
Thoughts on picoscope? My companies looking at getting new scanner and scope. Looking at verus, pico and few others
I watched it again. Going such detail in versus is not a good choice and don't know if possible, second I assume the location of map sensor in intake manifold is important to rely on map waveform. Am I correct in assuming that if map sensor is located on one bank end it have no way of knowing pressure pulses of other bank.
yes I'm on both Paul,good to see you experimenting with the in-cylinder pressure transducer technique, do you have a FLS (?) it would have been nice to see it on the inlet manifold along side of the WPS in cyl #4 or in fact the PV350 too :)
cool, good to have you hear! no FLS yet. hopefully soon
Great video Mr Paul. but my gut feeling says may be improperly adjusted tappet on intake valve or eroded cam profile. any way in both cases it not letting the valve seat on the surface any how i may be wrong if so please correct me
these are non adjustable my friend and are known for valve seat problems. thanks!
Hi Paul, how did this ended? Have you done map or pressure transducer waveforms from the repaired engine?
Great series! Did you ever post the various waveforms from after the repairs were made? I'm specifically interested in the post repair MAP sensor and in cylinder pressure waveforms to compare.
I did not, sorry
Paul,
If it wasn't for the map sensor or vacuum waveform to compare with the pressure transducer, how would you identify that the valve is leaking on that pressure transducer waveform?
Thanks
All of this is still new to me bro. But I think a device called a "first look sensor" would be in order. It takes vacuum and psi pulses and creates a signal you can plot on a scope
Looking forward to more pressure transducer videos!
without looking back were the towers leaning on the leaking cylinder ?
Also just to point out when using a sensor ground make sure it isn't a 'floating' one !
No, the towers looked identical.
Good point about the floating grounds!
Thanks Robski. I recognize your name from either the Pico forum or Autonerdz. Anyway I really appreciate your input
I have a question why would it be a dead hole on that cylinder on relative compression test on the mustard looking color n yet you have almost 155 psi compression?
What did the other good cylinders have?
that super low vacuum pocket on the power stroke screems leaking intake valve
Hey Paul, could you tell us who the guy with the cylinder compression dvd is again and where we can get it from please?
Thanks
Craig
John Thornton
Hey Scanner, this is way cool. I was wondering, for the engines where the MAP sensor monitor's only one side of the engine, if there might be benefit to putting a WPS 500 into the O2 Sensor and restricting the exhaust to get a better reading while cranking only? And of course putting one in the suspect cylinders spark plug hole so you could still see if the intake wasn't holding?
In this test, if the exhaust valve was not seating properly the WPS 500 in the cylinder would have read much lower while the Map sensor stayed consistent I suppose?
I do get the reason behind all this. You literally can't get to things on cars now days like you could in the good old days.
Thanks for taking the time man.
+ILTSYC thanks man! I like the way you think
The scope is the most exciting thing I've seen since the cell phone came out. I can't believe I've only known about them for a short time.
I first saw a Vantage Pro 5 or 6 months ago. on Shrodengers box TH-cam channel titled - Intro to Oscilloscope- with a DVOM. His main point was that a multimeter does not sample fast enough to catch some signals.
I'm fixing to get a pico scope after watching some of your vids. I'm really impressed with it and want to learn more about diagnostics. Hopefully I can switch my job to diagnostics sometime in the near future.
So, Paul, when the intake valve first opens the exhaust valve is still open due to overlap and when the piston is 90 degrees ATDC the stroke is moving at it's highest velocity and then the lowest pressure will occur. How is that repair coming? Who is doing the work?
Engines class is doing the work. It hasn't been touched yet.
Also, James Danner is my brother :)
I wish my scope had that type of filtering.
@31:50 ROTFLMAO!!!!! You know good and well that was somebody's first day on the job when that exhaust manifold was made!!!!
Darn. I really wanted to see the deficit valve and seat to get a visual to go along with all the graphs and scopes.
+consaka1 th-cam.com/video/s31gbHMgl58/w-d-xo.html
+ScannerDanner Thanks chief. Amazing how something that small doesn't look like much to the layperson but can make a big difference.
I got a suburban right now that you would just love. Comes in under fairly easy to diagnose. I am thinking about making a "Carnage" video series because that seems to be what comes my way. lol
In particular I think a triggering factor to its present condition is a possible backfire through a burnt intake valve. That was the main reason I wanted to see the video pictures. Once verified I would like him to see what such a problem can look like.
Thanks for all the awesome videos. I'd watch all of them if I could.
+consaka1 no problem and thank you!
Great Job!!!
but an exhaust vale leaking would not show up on an map sensor reading?
thanks Danner
Y'all are gonna put a whole motor in this thing for a head problem?!?! I'd have figured you'd have took it over to Cap's class and had them put a head on it.
Not sure what the plan is.
You did not detect the intake valve leak on your pressure waveforms because during the tests, valve leak was minimal owing to a lower cylinder pressure (No combustion was taking place, you removed spark plugs). Try in-cylinder pressure test on a twin-spark car (twin spark plugs), ignition enabled, one plug removed and you would see any valve leakage hopefully. I think Alfa Romeo had built such cars.
+Syed Imran Shah I was able to detect the valve leak in the pressure waveform, I just didn't know it at first. It was shown in the weak vacuum pocket during the "expansion stroke". I'm not sure which part I discussed this. Thanks!
I don’t know if you’ll get this or not Paul but I’ve just watched the series and just finished your part six here. And I was really interested to see that expansion pocket difference and I am trying to understand it in my mind. And you just said a week vacuum pocket, but it looks like a stronger one to me?... And have you done any more of these studies recently? Thanks again for all you do! Doug.
i will be waiting for the V configuration engine one with the single CAT restriction, it should be very intersting to.Or maybe stick a banana on the exhaust so we can get it faster,haha!
I just finished filming it today!
Gracias Paul!
Great video. Why are you replacing the entire engine to fix a leaky valve? Why not lap/hone the valve seats & valves, or replace the head?
I'm not a fan of scopes that are tied to a computer like the pico, at least not for long term use. You are married to that computers operating system and it's hardware. I have an oooold PC I keep around solely for a scanner I have because it requires windows 95 and a serial port. Stand alone scanners and scopes don't have this problem. Plus most decent oscilloscopes have much better resolution then even the most expensive pico. Just my 0 cents (after taxes).