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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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Got several but most exasperating is the A/C system. Usually

Customer Question

Got several but most exasperating is the A/C system. Usually is fine after starting the car. But occasionally driving down the road the air flow coming out the vents is significantly reduced and the air temperature is about ambient. Even turning the fan to 4 doesn't get a lot of air flow although I can hear the fan working hard. Usually shutting off the engine and restarting will fix the problem. It seems like there is an state electrically operated damper that controls air flow across the evaporator coil that is going closed when it shouldn't. Any ideas"
JA: How many miles are on the car? Have you checked the coolant level?
Customer: coolant level is fine and it has 137,000 miles but it has been doing this on and off for atl east four years. Car is a 2005 aveo.
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: I'd like to fix it myself but am stumped on where to start since it seems like an intermittent electrical or electronic issue. Do other aveo owners report this problem.
JA: Anything else you think the mechanic should know?
Customer: no
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Chevy Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Chevy
Expert:  TIM MOHR replied 1 year ago.

Hi, My name is ***** ***** the car is shut off at this point and restarted about 10 minutes later, does the a/c start cooling again for awhile?

Customer: replied 1 year ago.
It happened the other day and I shut car off for 2 seconds and A/C went back to normal good cooling.
Expert:  TIM MOHR replied 1 year ago.

ok, this is caused by the evaporator freezing up in the dash, this will diminish the airflow through it, and cooling capabilities, usually the frezing up is caused by a bad evap temp sensor, the sensor is used to momemtarilly shut off the compressor so the evaporator does not freeze over, you will need to replace the sensor,Tim

Customer: replied 1 year ago.
I see the logic but it does not explain why the air flow can suddenly recover just by cycling the engine on and off.
Expert:  TIM MOHR replied 1 year ago.

once shut off, it does not take long for the evap to thaw and start flowing again, we see it alot,Tim

Customer: replied 1 year ago.
BTW I have a 2007 GMC Sierra that all of a sudden will start to blow heated air. This too can be solved by cycling engine on and off. In both cases it seems to be an electronic module problem
Expert:  TIM MOHR replied 1 year ago.

on that one, its most likely a bad blend door actuator, but a blend door will NOT cause the diminished air flow, just the temp of the air,Tim

Customer: replied 1 year ago.
I'll try a new evaporate temp sensor but pretty I replaced it since this problem started. Thanks for the help
Expert:  TIM MOHR replied 1 year ago.

Anytime my friend, Please dont forget to rate me so I can get credit for helping,Thanks,Tim