tim, You have an absolute mess and have approached this backwards. Whenever you have mechanical issues, you need to fix them FIRST. Remember mechanical issues WILL cause electrical issues, but electrical issues WILL NOT cause mechanical issues. With that mileage, oil volume and black condition, along with cam position codes, you have a worn timing chain. The problem here is the lower end (Crankshaft & bearings) of that engine is most likely badly worn as well. I have no idea how much money you have in this mess, but you better be prepared to throw a LOT more money into it. Even with you being able to do a lot of the work yourself and getting parts at a good price, I can't believe you will ever be ahead of the game. Don't buy a new ECU or any other electrical parts UNTIL you correct all of your mechanical issues. I don't believe you needed those camshaft position sensors. Thousands of oxygen sensors get replaced for doing their job because people don't diagnose the issue correctly. Checking connectors and electrical connections is fine as was the cleaning of the throttle body, but stop throwing parts at it UNTIL you have a mechanically sound engine. I know this is not what you wanted to hear, but I really do feel sorry for the position you are in. I think it's time to cut your loses. Good luck.
2010 Enclave timing issue or ECM issues. Or gremlins.
Hi. Hello everyone. I'm happy owner of 07 Acadia for a almost two years now and have been reading acadia and this forums for a while now. It helped a lot to fix all my issues. But now, I become a happy owner of 2010 Enclave. And there is few issues I was unable to understand and hence resolve, so I'd like to try to call for a forums wisdom. Also it may help future generations of readers after all 
Thanks in advance guys!
So what we have?
In short: 163k miles 2010 Enclave. Stalling engine, timing chain codes, no data stream from CAM sensors.
Detailed version. Bought used as is with some engine issues. It seems that last few years under the last owner was quite rough. Oil was dark black and there was just 2.5 quarts of it in the engine when I drained it to change.
The main problem - engine starts, when starting there is a bit of a strange noise (My 07 Acadia sounds a bit different when starts) for just half-second, but then it's running good for... 30-90 seconds. And then just shuts off. Without any special effects like strange sounds, dash lights, revs going up or down. Just like if you shut it off with key. Quietly, peacefully and smoothly revs just drop to zero all of a sudden. Ignition stays on after that. I can start it up again like normal. Sometimes it goes for a minute or two, but not too long overall. I am able to drive it for a few minutes. But it tends to stall again when I stop. Also sometimes there is big hesitation happening when accelerating or just cruising. I'm not sure if "hesitation" is correct word, but I'll explain. So it accelerates pretty good, but then all of a sudden for just a mere moment (less then a second) it kinda loses power almost it looks like it's going to stall, but then it "wakes" up and continues as normal. If that happens, it only happens once during the acceleration event. It's not like it is doing this multiple time in any given minute. Also few times it died even while cruising at small speed (like 5-10 mph).
Of course there was check engine light and I happen to have pretty good OBD2 scanner (Autel AP200 (or Walmart's version - HyperTough HT200) - can't recommend it enough, for just 40-70 bucks it gives you MOST of the functions of dealer level tools). So after initial check I saw a LOT of different stored issues. But mostly it was related to the low battery voltage occurring historically. Like window motor calibrations etc. And there was P0008 and P0009 (engine position systems), as well as P0016 and P0017 (intake/exhaust CAM sensors bank 1) errors in regard to the engine. That got me alarmed. I reset everything to start from scratch and obviously after few runs MIL light came once again, and there was the same set of engine errors (no other errors though). So... starting to dig the forum. Yes, first thing everybody is talking about is timing chain issues and replacement. Ouch. But not so fast - there is good chance that the problem is with just sensors themselves. Very good evidence for this comes from the OBD2 live data - everything regarding CAM sensors is dead - no signals, no data, no nothing. Also they are much cheaper and comparably easier to change so I decided to go this way first. Spoiler alert - unfortunately it's not the end and it's more complicated.
What I have done so far?
In short: Cleaned throttle body and MAF, changed CAM sensors. Discovered some other weird issues. It's much better, but still not right.
In detail: Ordered all 4 CAM sensors. While waiting for them - changed air filter (I changed oil and oil filter first thing in the first day). Cleaned MAF sensor and throttle body. But, when I tried to adapt/relearn it via OBD2 I noticed very odd behavior. With ignition on, but engine not running when commanded manually any degree from the scan tool it goes there, but sometimes it seems like it just loses power and it flaps back to neutral state by it's internal spring. This happens for a mere split second and then it goes back up to the commanded state. Also it seems to have higher then usual high pitched whining noise when commanded states higher than 30%. AFAIK such a sound usually comes from inductors when they are overloaded/don't have enough voltage/too much amps - hmmm, that's strange. Since I have 07 Acadia too I checked behavior there (handy, isn't it? ) - maybe it's supposed to act like that? And no, it was acting as expected - commanded 50% - it stays all the time at 50% open. Indefinitely. Command to 100% - stays like that for as long as you command that state. And there is high pitch noise, but to much lesser extent. Next step I removed throttle body from Acadia cleaning it along the way and connected it to Buick, and yes - i triple checked, they are identical and interchangeable. Aaaand, moment of truth - is it bad throttle body (easy-peasy fix) or something else (e.g. wiring, PCM, gods mood etc). And unfortunately it's something else because known good TB acted the same weird way on the Buick. Summertime sadness Here is the video of it acting. Sorry, it's on another language, but I basically describe all of the above in it. July 17, 2022
Ok, so it's clearly something wrong with either wiring, engine PCM (ECM, ECU) or something else. Since I already had sensors on order decided to give it a try too. It took some time (and some hard words) to get to them, but finally I changed all of them with a new ones. What I noticed on this step - one of old sensors had marks/scuffs on it. It seems something mechanical actually hit it inside the engine. So timing chain might be real issue? Here is the photos: 3 new items by Tim Yoshi
Ok, so... what new sensors gave us? Hm... actually more questions than answers. With new CAM sensors it started fine, and worked for the whopping 6 minutes idling. I don't know if it subjective or if it was for real, but it seemed like idling become even better, smoother. Partly it could be because of cleaned throttle body and MAF sensor. But here comes tricky part:
1) It again died when I decided to give it a ride right after I started to move. summertime sadness intensifies Overall I it drove around the neighborhood for a good 30-40 minutes, sometimes stopping for a few minutes, sometimes accelerating hard. During that time it died just 5 times (including the first one after 6 minute idle) and had that "one-time stutter" during acceleration two or three times. So the problem is still there, but it's MUUUUUCH better now. But... it's actually weird, because of the next part.
2) OBD2 tool still does not see any data coming from the CAM sensors, as if I haven't changed them at all. And it still throws the same (P0008, P0009, P0016 and P0017) errors sometimes. But why then it become much better - dying 10 times less frequently - if computer still does not see any data as if like nothing changed?
What I suspect?
So I'm quite puzzled now. I said that already - that's why I decided to ask for the forum crowd wisdom.
As of now I can suspect:
1) Somewhat bad ECM (PCM, ECU - engine computer) or wiring. I checked all of the connectors when I changed the CAM sensors, but all of them looked perfect inside. Also I checked ECM connectors - they are MASSIVE but they also look perfect. Checked ground where I can see it - it looks surprisingly good given the age of the car. Also I checked voltage (on the main positive wire near the distribution box and body ground) with multimeter when car is idling and with engine shut off - nothing weird. Voltage stays more or less flat.
1.a) maybe something wrong with some of the connectors, but it's unlikely since all of the look good, and problem seems to be to wide and distributed to be linked to some one connector. Except maybe for the main PCM harness, but I checked it and it looks good.
2) Actually timing chain issues. I certainly have some electric gremlins, but it seems that it's possible that there is real timing chain issue ON TOP of the electrical problems.
What I plan to do next?
So far I'm leaning towards ordering a new PCM. It's just 176 bucks with free shipping. And it's a breeze to change it - just two clips holding it in place and two main connectors. And it's super easily accessible. It should come pre-flashed with the latest firmware and my car's VIN. So the only thing left is to bind my old keys. It's actually should be quite easy, albeit it's a long process - you have to turn on the ignition and wait 10 minutes. Then turn off. Rinse and repeat 3 times.
If that doesn't help, at least we'll need to see where it leads us - will the TB odd behavior be fixed? Will data stream from the CAM sensors return? If answer to all of the questions will be "NO", then likely there is something with wiring or something else. I don't know where to dig next in that case. If the answers will be "YES", but issue will persist, then it's likely chain. I'd like to avoid doing the timing chain work, but if it's inevitable, then, I guess I'll have to do it anyways. Few days of good weather, some stock of spare hard language and likely I'll be able to change it, not having any spare parts left along the way hopefully
So the grand question to you guys - what do you thing of all of that long story? Am I missing something? Any ideas? Any advice?
Thanks!
Thanks in advance guys!So what we have?
In short: 163k miles 2010 Enclave. Stalling engine, timing chain codes, no data stream from CAM sensors.
Detailed version. Bought used as is with some engine issues. It seems that last few years under the last owner was quite rough. Oil was dark black and there was just 2.5 quarts of it in the engine when I drained it to change.
The main problem - engine starts, when starting there is a bit of a strange noise (My 07 Acadia sounds a bit different when starts) for just half-second, but then it's running good for... 30-90 seconds. And then just shuts off. Without any special effects like strange sounds, dash lights, revs going up or down. Just like if you shut it off with key. Quietly, peacefully and smoothly revs just drop to zero all of a sudden. Ignition stays on after that. I can start it up again like normal. Sometimes it goes for a minute or two, but not too long overall. I am able to drive it for a few minutes. But it tends to stall again when I stop. Also sometimes there is big hesitation happening when accelerating or just cruising. I'm not sure if "hesitation" is correct word, but I'll explain. So it accelerates pretty good, but then all of a sudden for just a mere moment (less then a second) it kinda loses power almost it looks like it's going to stall, but then it "wakes" up and continues as normal. If that happens, it only happens once during the acceleration event. It's not like it is doing this multiple time in any given minute. Also few times it died even while cruising at small speed (like 5-10 mph).
Of course there was check engine light and I happen to have pretty good OBD2 scanner (Autel AP200 (or Walmart's version - HyperTough HT200) - can't recommend it enough, for just 40-70 bucks it gives you MOST of the functions of dealer level tools). So after initial check I saw a LOT of different stored issues. But mostly it was related to the low battery voltage occurring historically. Like window motor calibrations etc. And there was P0008 and P0009 (engine position systems), as well as P0016 and P0017 (intake/exhaust CAM sensors bank 1) errors in regard to the engine. That got me alarmed. I reset everything to start from scratch and obviously after few runs MIL light came once again, and there was the same set of engine errors (no other errors though). So... starting to dig the forum. Yes, first thing everybody is talking about is timing chain issues and replacement. Ouch. But not so fast - there is good chance that the problem is with just sensors themselves. Very good evidence for this comes from the OBD2 live data - everything regarding CAM sensors is dead - no signals, no data, no nothing. Also they are much cheaper and comparably easier to change so I decided to go this way first. Spoiler alert - unfortunately it's not the end and it's more complicated.
What I have done so far?
In short: Cleaned throttle body and MAF, changed CAM sensors. Discovered some other weird issues. It's much better, but still not right.
In detail: Ordered all 4 CAM sensors. While waiting for them - changed air filter (I changed oil and oil filter first thing in the first day). Cleaned MAF sensor and throttle body. But, when I tried to adapt/relearn it via OBD2 I noticed very odd behavior. With ignition on, but engine not running when commanded manually any degree from the scan tool it goes there, but sometimes it seems like it just loses power and it flaps back to neutral state by it's internal spring. This happens for a mere split second and then it goes back up to the commanded state. Also it seems to have higher then usual high pitched whining noise when commanded states higher than 30%. AFAIK such a sound usually comes from inductors when they are overloaded/don't have enough voltage/too much amps - hmmm, that's strange. Since I have 07 Acadia too I checked behavior there (handy, isn't it?
) - maybe it's supposed to act like that? And no, it was acting as expected - commanded 50% - it stays all the time at 50% open. Indefinitely. Command to 100% - stays like that for as long as you command that state. And there is high pitch noise, but to much lesser extent. Next step I removed throttle body from Acadia cleaning it along the way and connected it to Buick, and yes - i triple checked, they are identical and interchangeable. Aaaand, moment of truth - is it bad throttle body (easy-peasy fix) or something else (e.g. wiring, PCM, gods mood etc). And unfortunately it's something else because known good TB acted the same weird way on the Buick. Summertime sadness Here is the video of it acting. Sorry, it's on another language, but I basically describe all of the above in it. July 17, 2022Ok, so it's clearly something wrong with either wiring, engine PCM (ECM, ECU) or something else. Since I already had sensors on order decided to give it a try too. It took some time (and some hard words) to get to them, but finally I changed all of them with a new ones. What I noticed on this step - one of old sensors had marks/scuffs on it. It seems something mechanical actually hit it inside the engine. So timing chain might be real issue? Here is the photos: 3 new items by Tim Yoshi
Ok, so... what new sensors gave us? Hm... actually more questions than answers. With new CAM sensors it started fine, and worked for the whopping 6 minutes idling. I don't know if it subjective or if it was for real, but it seemed like idling become even better, smoother. Partly it could be because of cleaned throttle body and MAF sensor. But here comes tricky part:
1) It again died when I decided to give it a ride right after I started to move. summertime sadness intensifies
Overall I it drove around the neighborhood for a good 30-40 minutes, sometimes stopping for a few minutes, sometimes accelerating hard. During that time it died just 5 times (including the first one after 6 minute idle) and had that "one-time stutter" during acceleration two or three times. So the problem is still there, but it's MUUUUUCH better now. But... it's actually weird, because of the next part.2) OBD2 tool still does not see any data coming from the CAM sensors, as if I haven't changed them at all. And it still throws the same (P0008, P0009, P0016 and P0017) errors sometimes. But why then it become much better - dying 10 times less frequently - if computer still does not see any data as if like nothing changed?
What I suspect?
So I'm quite puzzled now. I said that already - that's why I decided to ask for the forum crowd wisdom.
As of now I can suspect:
1) Somewhat bad ECM (PCM, ECU - engine computer) or wiring. I checked all of the connectors when I changed the CAM sensors, but all of them looked perfect inside. Also I checked ECM connectors - they are MASSIVE but they also look perfect. Checked ground where I can see it - it looks surprisingly good given the age of the car. Also I checked voltage (on the main positive wire near the distribution box and body ground) with multimeter when car is idling and with engine shut off - nothing weird. Voltage stays more or less flat.
1.a) maybe something wrong with some of the connectors, but it's unlikely since all of the look good, and problem seems to be to wide and distributed to be linked to some one connector. Except maybe for the main PCM harness, but I checked it and it looks good.
2) Actually timing chain issues. I certainly have some electric gremlins, but it seems that it's possible that there is real timing chain issue ON TOP of the electrical problems.
What I plan to do next?
So far I'm leaning towards ordering a new PCM. It's just 176 bucks with free shipping. And it's a breeze to change it - just two clips holding it in place and two main connectors. And it's super easily accessible. It should come pre-flashed with the latest firmware and my car's VIN. So the only thing left is to bind my old keys. It's actually should be quite easy, albeit it's a long process - you have to turn on the ignition and wait 10 minutes. Then turn off. Rinse and repeat 3 times.
If that doesn't help, at least we'll need to see where it leads us - will the TB odd behavior be fixed? Will data stream from the CAM sensors return? If answer to all of the questions will be "NO", then likely there is something with wiring or something else. I don't know where to dig next in that case. If the answers will be "YES", but issue will persist, then it's likely chain. I'd like to avoid doing the timing chain work, but if it's inevitable, then, I guess I'll have to do it anyways. Few days of good weather, some stock of spare hard language and likely I'll be able to change it, not having any spare parts left along the way hopefully
So the grand question to you guys - what do you thing of all of that long story? Am I missing something? Any ideas? Any advice?
Thanks!
1 - 20 of 27 Posts
Yeah, I have that bit of an aries stubbornness.
Sorry about that. I certainly appreciate your (and everybody elses) time and completely understand that nobody will diagnose it perfectly over the internet. Down from where I come we have a saying, something like "dentist can't treat teeth over the internet" so I completely agree with you.Yes, I will definitely update the thread after any updates or resolutions.
Right now I have one quick update. Tried to collect a bit more data today, driving it around house. It become worse. Especially while driving, it felt that it was "trying to die" time to time but then recovered. And that happened quite frequently. And funny thing (not actually) - I noticed that it clicks door locks when this happens. Like it tries to unlock them or something. I believe that also might be symptom of some wiring issues. But, I have doubt's that it's engine control modules' responsibility to unlock the doors.
Hello, Have same model, sounds like a ground issue, check rear cylinder head, standing in front of vehicle it will be rightside of rear head, just below valve cover sealing surface, hard to find, might be one at other end of head,10mm hex bolt, very easy to to forget when valve cover gaskets replaced! If not the problem? If you can start it and run long enough to get your hands on main engine harness, on upper intake wiggle it, pull it, especially near cam sensors, and fuse box, good luck hope this helps you.Hi. Hello everyone. I'm happy owner of 07 Acadia for a almost two years now and have been reading acadia and this forums for a while now. It helped a lot to fix all my issues. But now, I become a happy owner of 2010 Enclave. And there is few issues I was unable to understand and hence resolve, so I'd like to try to call for a forums wisdom. Also it may help future generations of readers after all
So what we have?
In short: 163k miles 2010 Enclave. Stalling engine, timing chain codes, no data stream from CAM sensors.
Detailed version. Bought used as is with some engine issues. It seems that last few years under the last owner was quite rough. Oil was dark black and there was just 2.5 quarts of it in the engine when I drained it to change.
The main problem - engine starts, when starting there is a bit of a strange noise (My 07 Acadia sounds a bit different when starts) for just half-second, but then it's running good for... 30-90 seconds. And then just shuts off. Without any special effects like strange sounds, dash lights, revs going up or down. Just like if you shut it off with key. Quietly, peacefully and smoothly revs just drop to zero all of a sudden. Ignition stays on after that. I can start it up again like normal. Sometimes it goes for a minute or two, but not too long overall. I am able to drive it for a few minutes. But it tends to stall again when I stop. Also sometimes there is big hesitation happening when accelerating or just cruising. I'm not sure if "hesitation" is correct word, but I'll explain. So it accelerates pretty good, but then all of a sudden for just a mere moment (less then a second) it kinda loses power almost it looks like it's going to stall, but then it "wakes" up and continues as normal. If that happens, it only happens once during the acceleration event. It's not like it is doing this multiple time in any given minute. Also few times it died even while cruising at small speed (like 5-10 mph).
Of course there was check engine light and I happen to have pretty good OBD2 scanner (Autel AP200 (or Walmart's version - HyperTough HT200) - can't recommend it enough, for just 40-70 bucks it gives you MOST of the functions of dealer level tools). So after initial check I saw a LOT of different stored issues. But mostly it was related to the low battery voltage occurring historically. Like window motor calibrations etc. And there was P0008 and P0009 (engine position systems), as well as P0016 and P0017 (intake/exhaust CAM sensors bank 1) errors in regard to the engine. That got me alarmed. I reset everything to start from scratch and obviously after few runs MIL light came once again, and there was the same set of engine errors (no other errors though). So... starting to dig the forum. Yes, first thing everybody is talking about is timing chain issues and replacement. Ouch. But not so fast - there is good chance that the problem is with just sensors themselves. Very good evidence for this comes from the OBD2 live data - everything regarding CAM sensors is dead - no signals, no data, no nothing. Also they are much cheaper and comparably easier to change so I decided to go this way first. Spoiler alert - unfortunately it's not the end and it's more complicated.
What I have done so far?
In short: Cleaned throttle body and MAF, changed CAM sensors. Discovered some other weird issues. It's much better, but still not right.
In detail: Ordered all 4 CAM sensors. While waiting for them - changed air filter (I changed oil and oil filter first thing in the first day). Cleaned MAF sensor and throttle body. But, when I tried to adapt/relearn it via OBD2 I noticed very odd behavior. With ignition on, but engine not running when commanded manually any degree from the scan tool it goes there, but sometimes it seems like it just loses power and it flaps back to neutral state by it's internal spring. This happens for a mere split second and then it goes back up to the commanded state. Also it seems to have higher then usual high pitched whining noise when commanded states higher than 30%. AFAIK such a sound usually comes from inductors when they are overloaded/don't have enough voltage/too much amps - hmmm, that's strange. Since I have 07 Acadia too I checked behavior there (handy, isn't it?
Ok, so it's clearly something wrong with either wiring, engine PCM (ECM, ECU) or something else. Since I already had sensors on order decided to give it a try too. It took some time (and some hard words) to get to them, but finally I changed all of them with a new ones. What I noticed on this step - one of old sensors had marks/scuffs on it. It seems something mechanical actually hit it inside the engine. So timing chain might be real issue? Here is the photos: 3 new items by Tim Yoshi
Ok, so... what new sensors gave us? Hm... actually more questions than answers. With new CAM sensors it started fine, and worked for the whopping 6 minutes idling. I don't know if it subjective or if it was for real, but it seemed like idling become even better, smoother. Partly it could be because of cleaned throttle body and MAF sensor. But here comes tricky part:
1) It again died when I decided to give it a ride right after I started to move. summertime sadness intensifies
2) OBD2 tool still does not see any data coming from the CAM sensors, as if I haven't changed them at all. And it still throws the same (P0008, P0009, P0016 and P0017) errors sometimes. But why then it become much better - dying 10 times less frequently - if computer still does not see any data as if like nothing changed?
What I suspect?
So I'm quite puzzled now. I said that already - that's why I decided to ask for the forum crowd wisdom.
As of now I can suspect:
1) Somewhat bad ECM (PCM, ECU - engine computer) or wiring. I checked all of the connectors when I changed the CAM sensors, but all of them looked perfect inside. Also I checked ECM connectors - they are MASSIVE but they also look perfect. Checked ground where I can see it - it looks surprisingly good given the age of the car. Also I checked voltage (on the main positive wire near the distribution box and body ground) with multimeter when car is idling and with engine shut off - nothing weird. Voltage stays more or less flat.
1.a) maybe something wrong with some of the connectors, but it's unlikely since all of the look good, and problem seems to be to wide and distributed to be linked to some one connector. Except maybe for the main PCM harness, but I checked it and it looks good.
2) Actually timing chain issues. I certainly have some electric gremlins, but it seems that it's possible that there is real timing chain issue ON TOP of the electrical problems.
What I plan to do next?
So far I'm leaning towards ordering a new PCM. It's just 176 bucks with free shipping. And it's a breeze to change it - just two clips holding it in place and two main connectors. And it's super easily accessible. It should come pre-flashed with the latest firmware and my car's VIN. So the only thing left is to bind my old keys. It's actually should be quite easy, albeit it's a long process - you have to turn on the ignition and wait 10 minutes. Then turn off. Rinse and repeat 3 times.
If that doesn't help, at least we'll need to see where it leads us - will the TB odd behavior be fixed? Will data stream from the CAM sensors return? If answer to all of the questions will be "NO", then likely there is something with wiring or something else. I don't know where to dig next in that case. If the answers will be "YES", but issue will persist, then it's likely chain. I'd like to avoid doing the timing chain work, but if it's inevitable, then, I guess I'll have to do it anyways. Few days of good weather, some stock of spare hard language and likely I'll be able to change it, not having any spare parts left along the way hopefully
So the grand question to you guys - what do you thing of all of that long story? Am I missing something? Any ideas? Any advice?
Thanks!
Ok guys. Sorry for the lack of updates - last weeks were completely crazy. On top of the work on car I got few other projects going on simultaneously I'll disclose exact details after it all will finish and you will understand how crazy it was
But back to the car.
So far I changed CRANK sensor - of course that was not a problem
Then I stepped back and did a lot of research. Proceeded to borrow from my friend few pieces of much more sophisticated equipment to be 100% sure on what's going on. So I took two different pro-level diagnostics OBD2 scanners and a PC based oscilloscope.
One of the OBD2 scanners showed that indeed ECU have some troubles - most of the data was jumping randomly, and this was affecting only ECM - all other modules had perfect flat data outputs.
But another scanner showed no problems whatsoever. On top of that manual throttle body control (actuation tests) worked perfectly fine with it - no jerking, it just kept stable position, as expected.
So overall I think that ECM is fine - likely it's a bit quirky to diagnose and not all OBD scanners are created equal. That's why my friend has three of them, all different brands, just in case. THAT WAS THE CASE
So after that I decided to try to do relative compression test and direct sensor measurement. Relative compression is really nice test and it can show if there is difference in compression between rows of cylinders - this could happen if the timing chain is bad. Here is the video of how to do it -
Strangely enough - out of 5 tests I preformed compression looked perfectly fine on 4 of them and just one showed typical pattern when one row has lower compression than another. Hmmm...
To be 100% sure I connected oscilloscope directly to the sensors and took measurements. (Here is the video how to do it and what to look for in our beloved Enclaves -
) Then found reference etalon of how it should look and was shocked - on the right block (closer to the cabin) - both cams are out of timing by one tooth. On the left block (closer to the front of the car) - one of the cams is also one tooth off, but second cam is jumping all over the place +- 6-8 teeth! So yeah, now I'm 100% sure that it's a timing chain. I tried to deny it, but the truth is that I need to change the timing chain. But ok, I'm up to task now!
So here is the question. When I will be there, maybe it's a good idea to check something else and replace along the way? Obviously all the gaskets + some RTV silicone. Also I'm currently eyeing water pump as it's really cheap and should be removed anyways. Probably accessory belt too. Also I'm looking at the VVT sprockets and VVT solenoids, but this is a bit on the more expensive side, and I so far have big doubt's if I need to change them too? Maybe something else that I'm missing? Or just replace the chain kit (with sprockets) and call it a day?
P.S. Just to add a bit of a context here - I'm not planning to drive that car till the end of times, and no intentions to rebuilt it till it becomes like new - it's not lke some classics or something. Just to fix it so that it will be normally drivable till I get some money for something newer/better. I think I'll drive it for like 3-9 month, maybe 2-5k miles.
Thanks!
I'll disclose exact details after it all will finish and you will understand how crazy it was But back to the car.
So far I changed CRANK sensor - of course that was not a problem
Then I stepped back and did a lot of research. Proceeded to borrow from my friend few pieces of much more sophisticated equipment to be 100% sure on what's going on. So I took two different pro-level diagnostics OBD2 scanners and a PC based oscilloscope.
One of the OBD2 scanners showed that indeed ECU have some troubles - most of the data was jumping randomly, and this was affecting only ECM - all other modules had perfect flat data outputs.
But another scanner showed no problems whatsoever. On top of that manual throttle body control (actuation tests) worked perfectly fine with it - no jerking, it just kept stable position, as expected.
So overall I think that ECM is fine - likely it's a bit quirky to diagnose and not all OBD scanners are created equal. That's why my friend has three of them, all different brands, just in case. THAT WAS THE CASE
So after that I decided to try to do relative compression test and direct sensor measurement. Relative compression is really nice test and it can show if there is difference in compression between rows of cylinders - this could happen if the timing chain is bad. Here is the video of how to do it -
To be 100% sure I connected oscilloscope directly to the sensors and took measurements. (Here is the video how to do it and what to look for in our beloved Enclaves -
So here is the question. When I will be there, maybe it's a good idea to check something else and replace along the way? Obviously all the gaskets + some RTV silicone. Also I'm currently eyeing water pump as it's really cheap and should be removed anyways. Probably accessory belt too. Also I'm looking at the VVT sprockets and VVT solenoids, but this is a bit on the more expensive side, and I so far have big doubt's if I need to change them too? Maybe something else that I'm missing? Or just replace the chain kit (with sprockets) and call it a day?
P.S. Just to add a bit of a context here - I'm not planning to drive that car till the end of times, and no intentions to rebuilt it till it becomes like new - it's not lke some classics or something. Just to fix it so that it will be normally drivable till I get some money for something newer/better. I think I'll drive it for like 3-9 month, maybe 2-5k miles.
Thanks!
It's not like 3 month rental, but more like investment
If I will fix it right and it will be drivable again, only THEN I can sell it higher and buy next project. And yes, that's an investmesment in experience coz I'd like to continue work on cars. and sorta challenge to myself. Like if I'm really up to a task. And especially since I've heard this job can cost around 3-5k at the shops it makes it even more lucrative to do it myself. So the main question was and still is - what to change/service along the way when I will be down there?
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