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.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: car over heating within 2 miles and using all the water in the radiator

A thermostat that is stuck closed will cause the engine to overheat quickly. Do not drive it or engine damage will occur! I suggest having a technician, such as one from YourMechanic, come out and diagnose and repair your cooling...

Q: Car won't go in drive or reverse what do i do

The first thing to check is to see if the shift cable is not broken or has a bad grommet end connector. Go to the shift linkage at the transmission first to see if cable is connected. If it is...

Q: Quits running multiple times

Hey there, thanks for writing in about your 2010 Lexus HS250h. Your problem is most likely the power integration relay/module (what you're referring to as the horn relay). The component is used to supply power to the horns, keyless entry...

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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.