[Crow1307]

I took my 2010 Malibu in to diagnose an oil leak. It has a 2.4L ecotec with 116K miles on it. It was determined the leak was coming from the timing chain cover seal. Once the work started it was discovered that the plastic timing chain guide had busted and the chain, tensioner, and guide all needed to be replaced. The work was completed and I took it to get gas and after getting gas I got the check engine light. Code was P0010. I brought it back and the cam position actuators were replaced. Got it back again, drove it to, from, and to work and when I went to come back home on that second day the light came back on. Code was P0172 saying the fuel system was running too rich. Brought it back to them, and I was told they did a hard reset to the computer system. They continued to drive it for the next 3 days using up 3/4 of my tank in the process. They said all looked normal and no codes popped so I could pick it up. I got the car, put gas in, took it to the car wash, and ran it for a bit while I was vacuuming (it was cold out). Brought it home. It sat in the drive for a while, I started it and it sat for about 5 minutes and when I went to pull the car into the garage and the light was on AGAIN! I took it to check the code and it popped a P0172 again. I’ll be taking it back in again on Monday, but does anyone have any idea what the cause of this could be? They claimed it never came on while they had it. I’m losing my mind over here.

 

[Drunken Elvis]

Has this vehicle had regular oil changes? Almost all of these ecotec engines I see that need a cam chain are very dark inside with sludge.
Idling this car in your driveway and at the car wash may not have been the best thing to do after having this work done. I would buy some fuel system/injector cleaner and run put it in the tank and go for a long highway drive. Keep and eye on the engine temperature. Does it rise quickly and stay and stay about half way? Air filter not more then 5 years old? Have the exhaust system checked for leaks, including the flex pipe as the engine moves underload.

 

[Crow1307]

Has this vehicle had regular oil changes? Almost all of these ecotec engines I see that need a cam chain are very dark inside with sludge.
Idling this car in your driveway and at the car wash may not have been the best thing to do after having this work done. I would buy some fuel system/injector cleaner and run put it in the tank and go for a long highway drive. Keep and eye on the engine temperature. Does it rise quickly and stay and stay about half way? Air filter not more then 5 years old? Have the exhaust system checked for leaks, including the flex pipe as the engine moves underload.

I wound up replacing my air filter and cleaning the mass air flow sensor with the proper cleaner and the light went off. I then did about 25 miles of highway driving and it stayed off. Thanks for writing to me and I’ll reference your comments and follow up if it comes back on.

 

[Crow1307]

So the light has just come back on. After cleaning the mass air flow sensor and changing the air filter, I drove it for a week with no issues and today the light came back on with the same code. I will put some fuel system cleaner in it and drive it to try to see if that helps. The temp currently stays just under half way. I have not checked the exhaust. This is just really frustrating to have these problems now considering they were not tripping my check engine light prior to the work being done.

Is it possible that the timing chain being off by a tooth or two may be causing this issue?

 

[Drunken Elvis]

The new chain probably came with colored links that line up with the timing marks on the sprockets. This makes it so easy to install properly that a child could do it. If the timing were off by a tooth, I doubt the engine would ever run exactly right. Rough idle and lack of power come to mind.

You have not said what code is now present. Has the P0010 or P0172 returned or a new code?

You could spend a lot of time and money trying to cure this problem or
A diagnostic shop with the proper equipment should be able to point you in the right direction. Often this is the cheaper way to go.

 

[Crow1307]

The new chain probably came with colored links that line up with the timing marks on the sprockets. This makes it so easy to install properly that a child could do it. If the timing were off by a tooth, I doubt the engine would ever run exactly right. Rough idle and lack of power come to mind.

You have not said what code is now present. Has the P0010 or P0172 returned or a new code?

You could spend a lot of time and money trying to cure this problem or
A diagnostic shop with the proper equipment should be able to point you in the right direction. Often this is the cheaper way to go.

It is the P0172 again. I’ll be taking it back to the shop. These issues were never present. I take it in, they replace the timing chain. I get it back and check engine comes on showing cam position sensor. Bring it back and they replace the sensors. I get it back, drive it 3 times and light comes on the 4th time. Now it is the p0172. They say they hard reset the computer. They also keep the car and drive it for a while and use 3/4 of my gas. I get it back, and code popped again, which is when I started this thread. I replace air filter and clean air flow sensor. Light goes off. I drive it for about 250 miles over the course of the week and it comes back on today with the same code. I was just trying to get any other ideas from anyone on here cause I’m sick and tired of leaving my car at the shop and driving a loaner.