Random Idle Surge. Intake leak? [Archive] - GrandAmGT.com Forum

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kornfox
10-20-2007, 07:08 PM
On my 2001 grand am (v6), I will have an occasional idle surge. The engine will rev high, recover, and rev high again. Usually rythmically. When I brought it in and had it checked, I was told that an intake gasket needed to be replaced and it was a $900 job. I assume that the engine is pulling in air from the leak and the air/fuel ratio is distorted and causing the surge? Does anyone know specifically where this gasket would be located? On the bottom of the intake manifold? How difficult of a job would this be? Thanks.

nickofcourse
10-20-2007, 09:13 PM
On my 2001 grand am (v6), I will have an occasional idle surge. The engine will rev high, recover, and rev high again. Usually rythmically. When I brought it in and had it checked, I was told that an intake gasket needed to be replaced and it was a $900 job. I assume that the engine is pulling in air from the leak and the air/fuel ratio is distorted and causing the surge? Does anyone know specifically where this gasket would be located? On the bottom of the intake manifold? How difficult of a job would this be? Thanks.

use the search feature, and welcome to the forums.

AaronGTR
10-21-2007, 12:33 AM
You could always have an intake leak, but it's usually the lower intake gasket and it leaks oil and coolant, not air. The uppers usually don't leak. If you have a vacuum leak it's more likely coming from one of the hoses that attaches to the upper intake manifold.

Surging idle like that though is usually an electronic problem though on these cars. A fouled O2 sensor, dirty MAF sensor, or a bad IAC motor or TPS sensor.

kornfox
10-21-2007, 11:47 AM
use the search feature, and welcome to the forums.

Thanks for the advice but I had searched. I couldnt find anything related to a leak of air due to a failed gasket, just coolant. My car is not leaking coolant and I havent seen this issue. Thats why I was curious about an air intake leak and if it was common. Also, how easy it would be to fix.

You could always have an intake leak, but it's usually the lower intake gasket and it leaks oil and coolant, not air. The uppers usually don't leak. If you have a vacuum leak it's more likely coming from one of the hoses that attaches to the upper intake manifold.

Surging idle like that though is usually an electronic problem though on these cars. A fouled O2 sensor, dirty MAF sensor, or a bad IAC motor or TPS sensor.

Makes sense. I'll check those out, thank you. I feel I was probably misdiagnosed by the "oh so knowledgeable" techs at my local firestone.