I am Oscar, and this is my first post. I am a long time lurker, but now I find myself with a question that I cannot find any information about, and I am wondering if anyone here knows anything about it.
I want to know if Chevrolet Aveos with LXV engines (2009-2011 models) have intake manifolds that contain a PCV valve inside of them, that when bad, can cause a vacuum leak and premature deterioration of the valve cover?
https://www.youtube.com/watch?v=kqvBSK2tluk demonstrates how some Chevy Cruze models have a PCV valve INSIDE the intake manifold that when bad cause a vacuum leak and deterioration of the valve cover. Note how that model also has a PCV valve inside the valve cover, so it has 2 total. At first I thought this didn't apply to my car (2009 Chevrolet Aveo LT), but then I saw https://www.youtube.com/watch?v=_mQ6i4UUy-Q . It is a Chevy Cruze of the previous generation, relative to the one from the link above. That valve cover is IDENTICAL to the one on 2009 Aveo, and all other LXV engine Aveos. It has a PCV valve inside the valve cover, and now i want to know if there is a PCV valve inside the intake manifold too. Afterall, each of the previously mentioned vehicles has an "Eco-tec" engine (when we all know "Cheapo-tec" is more appropriate).
BELOW EXPLAINS MY P0171 BLUES THAT CAUSED ME TO WONDER THIS ABOUT THE INTAKE MANIFOLD
I have been fighting a P0171 that occasionally comes on.
On a cold start, the LTFT stabilizes to a normal LTFT value (between -3 and 10) when parked and the transmission is first switched from Park to Drive (initial cold start stabilized LTFT value temperature dependent, closer to -3 when it is cold outside, closer to 10 when it is hot outside). Then the LTFT's increase as the engine temperature increases. When the car has been running for a good 30 minutes, the LTFT will maximize at 29.7, at idle, if it is hot outside and the P0171 code may get set. The LTFT does stabilize at lower values as the value of engine load and rpm increase for all engine temperatures. The last statement makes me think a vacuum leak, but I have smoke tested my car's air intake and valve cover and found no vacuum leaks, now I suspect the problem to be in the intake manifold, if it has that pcv valve, and want to see if anyone knows whether the Aveos with LXV engines have intake manifolds with PCV valves in them.
To address the occasional P0171 I have changed:
1) Air intake ducts connected to the MAF,
2) the MAF (an AFTERMARKET ONE, maybe this could be it too),
3) Valve Cover + gasket,
4) Exhaust manifold Gasket (the maniverter and the flex pipe both looked good and had no holes),
5) upstream and downstream O2 sensors,
6) spark plugs and ignition coil boots, and
7) Fuel pump.
Changing 1) got rid of the constant P0171 my car initially had, but changing 2) - 7) has done little to nothing to address the issue of the LTFT increasing, for the same RPM and Load, when engine temperature increases.
I'm wondering if my intake manifold has a bad PCV valve that is causing the LTFT to increase with engine temperature.
Thanks everyone for reading, I hope to hear back from some of you. If I end up changing the Intake Manifold I'll post what effect, if any, it has on the fuel trims.