Last weekend the check engine light came on. 2009 SS Auto with 99k miles. Right before the light came on I had just noticed that I was showing more boost than I had ever show. I use a SuperChips tuner and my boost is typically limited to about 15" to 16" in all gears. I was suddenly able to achieve 23" of boost! Other than that difference, the car runs totally normal.

So I hooked up a scanner and it gave me P0016 & P0017. So I changed both VVT Solenoids with Dorman 917-215 & 917-216. I cleared the codes but the light came right back on. I had read that sometimes dirty oil can contribute to the code, so since I was due for an oil change anyway, I performed one.

I cleared the code but it came back, but this time only P0016.

I have read a number of threads about this code, but none seem to mention anything about the potential difference in boost - if that has anything to do with this.

I am thinking this may have something to do with a timing chain issue. The car makes no noises and runs fine.

Any help would be appreciated. Kevin

 

P0016 means the timing chain has a problem. Nothing to do with bad sensors or VVT valves.

That might also be the reason for high boost because of the valve timing.

 

It may or may not be related to the overboost. First thing is check the codes again, those codes are not for the VVT solenoids. The codes for VVT solenoids are P0010/11/13/14. Interesting that there is no overboost code logged.

One thing you could do is pull the valve cover and check if there is any slop in the timing chain. If it's loose, you'll probably want to replace timing chain, balance shaft chain, all guides and tensioners, as well as the water pump. There are kits that have all this.

If it's still overboosting after that, then it may be the boost control solenoid. Cross that bridge when we get there. There are other causes.

 

Thanks guys. As soon as it stops raining long enough I will pop off the cam cover and have a good look around. I will report back.

 

You'll need to pop off the front timing chain cover also.

 

I finally have the valve cover removed. The top of the timing chain does have some slop in it. I will remove the front timing chain cover this afternoon. Should the chain be taught between the cam gears?

 

It should not slump. But that is not necessarily what is up, most likely it was loose enough to skip a tooth.

 

When turning the engine over manually, there were times that the chain is taught on top and others when it was very loose. I will take a picture tomorrow to show the difference. I have ordered everything I need to replace everything and the last few bit will be here tomorrow.

Thanks for your advice. I will keep you updated.

 

Sounds like you were turning it anticlockwise. If so, each time it bunched up it skipped a tooth.

 

Turning the engine counterclockwise is a big NO NO. OUCH