A big thing we’ve seen a lot of over the past year or so, has been timing chain problems on the Chevy Traverse, Saturn Outlook, GMC Acadia, and Buick Enclave. All of these SUV’s have the 3.6 liter V6 engine with dual overhead cams. What is happening on these vehicles is that the timing chains are stretching which leads to correlation errors with the cam sensors and actuators.
Usually we see this only on 2007-2009 model year vehicles. After 2010, General Motors has seemed to correct the problem with updated chains and ECM calibrations.
This was first thought to be caused by lack of oil changes, and there was a recall to update the vehicle’s computer to shorten the oil life monitor. This was supposed to get customers in sooner to change their oil, thus hopefully eliminating sludge build up, heat, and excess wear and tear that leads to the chains actually stretching some.
On the older models, this didn’t seem to matter. They would still be coming in with the check engine light on and usually running rough. There would most times be trouble codes for cam sensor/actuator correlation, usually on bank 1. Something like a p0017 and a P0008 would definitely mean the engine has stretched chains. Now, this is no small job!! The entire engine and transmission has to come out on a lift table. This requires much work, just even disconnecting all the wiring harnesses and sensors. The air conditioning system has to be recovered and lines removed from the compressor. The trans cooler lines and power steering cooler lines have to be disconnected. The shift linkage, complete engine harness, upper and lower radiator hoses, and fuse box just all come out just to name a few.
Then, once the engine is out and accessible, the real work begins! After removal of the valve covers, intake manifold, power steering pump, belt, tensioner, water pump pulley, alternator and crank pulley, the aluminum front cover can come off. There are quite a few bolts that hold it on and they all have a small rubber seal that goes on each bolt. Now, finally, you can access the actual timing chains where the problem lies.
Once you can get your hands on the chains, you can easily feel the excessive play in the chain from being too far stretched out. This leads to the timing being off, setting the check engine light on, and usually a rough idle. There are three different chains that will require replacement with the updated parts. There is also some special tools needed, such as camshaft holding tools, etc, that are needed to do this job.
The chains, guides, hydraulic tensioners can all be taken off and the chains removed. Now the engine can be placed at top dead center and the holding fixtures installed on the cams once the timing marks are lined up on the crank gear and oil pump cover. The left chain goes in first, following the timing procedure, then the primary chain, then finally the right side cam chain. Once all the chains have been installed, and their guides and tensioners, the process of putting it all back together can begin. Let’s just say this is NOT a job for the backyard mechanic. It will take even the most experienced technicians the better part of a whole day to do this job, sometimes longer.
Luckily for most customers, the powertrain warranty covers this repair up to 100,000 miles. Otherwise it would be very expensive to repair. So, if you’re having these symptoms, don’t wait another minute to go in to your dealership and get this checked out!
Below are two pictures so you can see just how involved this job is. The first pic is of the entire engine/trans assembly out of the Traverse and ready to disassemble. The second pic is a close up of the three timing chains that will be replaced. You can see there are quite a few sprockets, and things to go around!
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i want to watch how to chang timeing balt
Mine is at the shop now to get this done. <3 yr, <36K mile. Not too impressed. Symptom was the check engine light. Had noticed the oil change interval has shortened quite a bit recently on the monitor. Found out today that last time in <1 yr ago they reprogrammed the ECM. Went from 10K oil change interval to 3K. Hmmm.
Yes. There is a new program for the computer. GM found that the calculations for the oil change monitor system were incorrect causing the interval to be too large. They suspect that may have had something to do with the timing chains wearing out.
My 2009 traverse is now in for the timing chains. 86,000, but had this vehical new with all kinds of electrical probelms. Car would look you out, all the guages went nuts, the cruise control would not disingage.
do you have to line all the dots up on this engine before you remove chains? If not then why
No, you do not have to line up the marks, since during the repair they will all be out of time anyway. You could do that thou, just to have everything close to the correct position. That may make it a little easier to line everything up.
My ’09 is in now for this repair. Had a check engine code last summer that was something about a delayed response from some sensor (can’t remember exactly). Took it in for the oil change interval recall, and the code never recurred.
The two codes now are from the crank position sensor and one camshaft position sensor. Had it not been for the check engine light, I would not have known anything was wrong.
The service writer told me that the mechanic who does this work has gotten really proficient at it!
All in all, we’ve been very happy with the vehicle.
I am not sure how long ago you posted to this forum. Today is 10.5.2012 and the dealership has my 09 Traverse and is attempting to fix the camshaft. They called me yesterday asking if I had service records for all my oil changes because of excessive oil build up in the engine caused from lack of oil changes ( so they say). I always change my oil. wondering if you had any issues about oil build up on your 2009 when you had it repaired? I also see that oil build up is a known problem with this make and model. I am afraid of them voiding my warranty because of something that is a known issues. I am also worried about having more probs down the road, since replacing the camshaft effects so much of the car… let me know :) thanks
If you have your receipts, then you are in the clear. Yes, oil buildup is a problem. GM even came up with a reprogramming of the oil life monitor so the light will come on sooner.
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I was about to swallow my heart when I got the codes from Auto Zone. – All the same ones mentioned in the article. I have a 2009 Acadia. I baby it with freqent, quality oil changes, but have a 120 mile commute daily to work. It now has 98,500 miles on it and it JUST started running funny yesterday so I went to Auto Zone for codes.
A bit petrified right now….FINGERS CROSSED that I am one of the “most customers” covered in the 100K powertrain warrenty. A little confused because the warrenty states timing belts covered up to the first maintence interval – but I can’t find what that interval is in any of my documentation. Anyone have any ideas?
Don’t worry. If you have all your oil change receipts, this is still under the factory 1100k powertrain warranty.
We just purchased a 2012 traverse on 12/31/12. It has 500 miles on it. It is at the dealership for the 2 nd time in 8 days. The check engine light is on. 1st time they said they reset something that it should go off after cranking it 7 times- Not. So, now they are saying the acuactor sensesor is bad. Will this require taking the engine out? Do u know if I can get my $ back? We can’t afford these problems on a brand new car.
Well, the repair depends on what part is bad. With such low miles I would not think it serious. We would need the actual code number to be sure.
No i don’t think it would be easy to try to get your money back. That is always a difficult process. A check engine light is not grounds for a buy-back.
Thanks so much for posting this info. I’m having this done to our ’07 Outlook under warranty. Our dealer is recommending that they replace the actuators at the same time since they will already have the engine apart. The additional charge to replacing the actuators is $1200. Have you seen issues with the actuators as well or is it just the timing chain? Should I get this done?
Thanks again.
If this repair is under warranty, you should not have to pay for anything ! Nothing !
The actuators always get replaced when doing this job under warranty. The cost is way out of line. Sounds to me like they are trying to get you to pay for the whole job !
Good to know. I’ll just have them do the warranty work. Thanks again.
I have another question about 2012 Chevy Traverses (not timing chains related, I hope!). We have noticed that when initially driving the car after a night’s rest, about a block from the house there are two noises maybe 3-5 seconds apart coming from under the hood….maybe somewhere in the engine, like something engaging. There is also a definite slight, feel to engaging (similar to shifting but more noticeable). Our son has a 2012 Traverse and experiences the same “happening”. Do you know what this might be? Thank you!
Not a timing chain problem. Could be the A/C clutch engage/disengage. It is still under warranty, so take it in to get looked at.
I have an 08 Acadia (not under warranty) whose check engine light came on recently and it had same codes mentioned for timing chain. Before I could get appointment to take it in, it started making horrible sound and died after coming to a stop. It will start up just makes loud clattering noise. Been in garage since waiting on tax return to have fixed. Does it sound like timing chain broke? If so what kind of damage am I looking at? I really love my car and have had no other problems so I hope a new motor isn’t necessary :(
Yes, it does sound like either the timing chain or a chain tensioner broke. If this happened, the engine needs to come out and taken apart. There is a possibility that the valves may have hit the pistons. That would require new cylinder heads. At the least, the chain and tensioners need to be replaced.
I had my timing chain replaced yesterday on my 2007 Acadia. It doesn’t seem to be driving as smoothly as before. It almost feels as if it is jumping up and down as I am driving. It feels as if there is a problem now with the shocks, if there are any on this car. What could it be?
To replace the timing chains, the engine and frame were removed. It is possible they left something loose or the front end alignment is off. Take it back ton them right away.
I just paid over $200 to have 2 cam sensors replaced in my 2009 Saturn, unaware of this timing belt issue. needless to say the problem was not corrected and now have an appointment with a dealer to correct it. Do they replace the cam sensors when doing this repair? I wuold like to get my money back at least for the parts.
No, the sensors are not replaced during the timing chain repairs. The codes in the computer pointed to the cam sensors, but that is never the problem. They mis-diagnosed the problem and it did not fix it, so you should get a full refund.
It was not the dealer but a garage mechanic that initially said it was the sensors (diagnosed by computer) and did the work. I think someone should be sending a letter letting us know that if the engine light comes on we should take it directly to a dealer since this is an issue. I want to be reimbursed for the work by the company. I plan on talking to the dealer directly regarding this…What a waste of time and money!
Just had the check engine light come on for the Camshaft correlation (Thanks OnStar)in my 2009 Traverse. Hoping whatever the problem is, it will be covered under warranty. The dealership just told me Chevy extended the timing chain warranty to 120,000 or June 2019. Obviously they know there is a problem. I just hope it’s my problem so it’s covered!
the timing chain can be replaced without removing the engine and trans on outlook. I did
Just got my 2009 out of the repair shop with timing belt failure. Supposedly, some pin from some pump was missing. Can someone share more about their experience with the powertrain warranty? What is the process?
By the way, now the Travey is shaking as if it does not have a suspension. I’ve got to take it back to the shop.