[craig85006]

Hello.

I just had to have the purge solenoid replaced on my 2011 Cruze LTZ RS. I had the P0171 (lean/emission) code pop up along with P0300 (misfire). I am still thinking my MAF is not reading correctly because after I drive the car for awhile with the ac on, it does not seem to be as spunky on acceleration vs when I first start to drive it, especially during the warmer hours of the day. Additionally, after I let the car sit for a few minutes and the start it again, the idle fluctuates drastically, sometimes resulting in the engine stalling. This leads me to believe I have an MAF issue. I have had my car in and out of the dealer several times over the last couple of weeks to no avail. I think my MAF is acting up, but not enough to throw a code. A friend of mine seems to think it's the MAF as well because his Jaguar had the same issue. The problem disappeared after he replaced the MAF.

I would like to know which brand of MAF is the best for a stock intake system. I have been looking on-line, and the prices vary drastically, ranging from about $23.00 up to $100.00. I cannot modify the intake system from factory because my car IS still under warranty.

Is ISUMO a good brand or should I still it BOSCH? Other manufacturers?

Anyone have any thoughts?

Thank you.

Craig Lambert
Phoenix, AZ

 

[EricSmit]

Don't just throw parts at it. Take it to the dealer, enjoy your courtesy vehicle.

 

[winks79]

I would test and make sure that is the problem before spending the money on a MAF. Have you tried cleaning the MAF? If not, that would be the first option. Use ONLY MAF sensor cleaner for this, not carb or brake cleaner. I have seen parts of a bug or a small amount of dust/trash on the MAF that cleaning has cured many issues. If that does not work then unplug the MAF and see what happens. You should be able to unplug the MAF and see if it runs any better with it unplugged. It will probably throw a code but if the issues you speak of do not happen with it unplugged, then I would say the MAF most likely is the problem. Have diagnosed many MAF issues like this over the years and has always worked for me.

 

[Robby]

In this case, the maf is the LEAST likely component to cause this problem. If you have enough money to throw parts at it based on a guess, you have enough money to get it correctly analysed and repaired.
Based solely on your description, your car may have a failed check valve in the intake manifold (requires manifold replacement) and a failed burst (we call it pcv) disc in the camcover (also requires cover replacement).

Ideally you should have a dealer perform a accurate diagnosis to avoid wasting your money.

Rob

 

[jblackburn]

I would lean towards PCV as well.

You can check these yourself - the burst disc is under the spark plug cover & should not be hissing from the vent port while the engine's running.

The check valve in the intake manifold at the back; just remove the corrugated hose & clip and peer into the hole with a flashlight. A little orange dot should be visible on the back wall of the port - that is the check valve.

 

[craig85006]

When I pull the spark cover, I presume it's the black cover that reads "EcoTec," I hear nothing. I unplugged the MAF while idling, and no change, not even a fluctuation in the RPMs. I have attached a couple of pictures of what I think you're describing as the check valve. I looked inside and could not see an orange dot. Seemed to be a bit wet with oil around the opening.

I am getting really frustrated and annoyed with taking the car back to the dealer!!!

 

[craig85006]

When I pull the spark cover, I presume it's the black cover that reads "EcoTec," I hear nothing. I unplugged the MAF while idling, and no change, not even a fluctuation in the RPMs. I have attached a couple of pictures of what I think you're describing as the check valve. I looked inside and could not see an orange dot. Seemed to be a bit wet with oil around the opening.

I am getting really frustrated and annoyed with taking the car back to the dealer!!!

 

[EricSmit]

If you don't see an orange dot and all you see is oil, then you need a new intake manifold. Your check valve is gone.

 

[Robby]

I hope someone more savvy than me will provide a link to a photo on this forum of what you should be seeing. A strong (like a pinpoint led) is helpful to look down the port and you have photographed the correct opening.

Rob

 

[jblackburn]

This is what you should be seeing. You may need to clean it off with a Q-tip. If it's not there, the intake manifold should be replaced (or look into XR's PCV system fix).

 

[Robby]

Thanks on behalf of the OP jblackburn.

Rob

 

[craig85006]

I took the car back to the dealership from where I purchased the car and tried to explain to the service adviser. He would not accept the car without a check engine light being present, nor would his "buddy" over at the Chevy dealership across the way feel comfortable in doing it either. I tried to explain that this problem would not throw a code being the check valve is a non-electrical component. The Chevy friend says he had not heard anything about an "orange dot." I looked again based on your photograph, and the orange part is I am getting really frustrated! I am going to file a complaint with the corporate office of the selling dealership and have this documented with the warranty company.

 

[jblackburn]

Sigh...I hate dealers.

Perhaps this will help.

If not...set a CEL. Pull out the oil dipstick slightly, and drive it around a parking lot. It will cough and try to die. Should throw all the codes a bad PCV normally does.