Skip the auto shop - Our mechanics make house calls

Q: Compressor it AC Belt?

asked by on

When I turn my car on, whether the AC is running or not, under the hood has a louder than usual running noise. I was told it could be the compressor or AC belt. Is this what it could be? Also, if my AC is on high I notice non-odorous smoke coming from the vents. Thanks!

My car has 119097 miles.
My car has an automatic transmission.

A: Hi there. If the belt is failing or if the ...

Hi there. If the belt is failing or if the AC pulley bearing is failing, then this noise can occur. I usually remove the belt and check each of the pulleys to see if any of them are rough indicating a bearing failure. I would then replace any questionable parts. If they are fine, then the noise may be coming from the engine. As for the smoke from the AC, if the system is working good then most of the time this is condensation that is coming out. It usually is the result of a clogged evaporator case drain which allows moisture to build up and then it ends up coming out of the vents like this. If you need to have the engine noise and the AC vapor issue looked at, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the noise and smoke problems in order to have this correctly addressed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Hard transmission shifting, second time replaced

Hey there. This may be related to a bad or failing transmission control solenoid or potentially the control module itself. As you know, the transmission control module has various sensors such as vehicle speed sensors, wheel speed sensors, throttle position...

Q: Sporadically overheats , have replaced water pump and radiator hoses and thermostat. What else could cause the overheating?

It is possible that you have air in the system or that air is somehow being pulled into the system. A very small gasket leak can sometimes not be enough for liquid to leak but will allow air to enter...

Q: My car won't start with a new battery

Hey there. You may not be having a battery problem, but the charging system may not be charging the battery correctly. This vehicle has had possible problems with the engine control module since the ECM controls the alternator as to...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.