Skip the auto shop - Our mechanics make house calls

Q: My car is making a squealing sound when it cranks and when I turn on the A/C

asked by on

Hi, I have a 2009 Hyundai Elantra and my car squeals really loud when I first crank up, the car does settles after a couple minutes. If I try to drive while the car is squealing, it gets even louder. Also, my car squeals when I turn on the A/C. Do you know what could possibly be my problem? I have recently gotten a new alternator belt. Also, I think that possibly a bolt or something could be missing or loose, based on what one mechanic told me.

My car has 100000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. What you’re desc...

Hi, thanks for writing in. What you’re describing sounds a lot like an AC belt that is loose or the serpentine belt on your alternator loose (or a combination of both). A common mistake that some mechanics make is not properly tightening the alternator after replacing the belts. The fact that the previous mechanic indicated that there may be a bolt missing also raises a red flag to me that the alternator might be a problem.

However, you mentioned also that the car squeals when you turn on the AC and that it gets louder as you drive. When a belt is loose it creates a harmonic squeal, and as the belt moves faster (when you accelerate) it progressively gets worse.

I think the best thing you can do is to find a another mechanic that can fully inspect your alternator and AC belts, replace any lost nuts or bolts on your current alternator, and get rid of that annoying squealing sound. A certified technician from YourMechanic can come to your home or office to inspect you AC squeal and let you know exactly what needs to be done.

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: Cruise control not working in 99 elantra

Hello, thank you for writing in. The vehicle is going to need further testing on the cruise control switch and the module. Either of these may be malfunctioning. The switch activates a servo motor that holds the throttle in place,...

Q: My car hesitates and I have to press on gas hard for it to kind of smooth on out.

Typically, what you are describing is due to an engine management fault(s) and such faults occur in ignition system components, the fuel system, and/or the air induction system. A possible first approach is to just simply make sure that the...

Q: water comes into passenger side while car washing

When it comes to water leaks only a hands on test like you did will tell you where the leak is. Why the leak happens is most likely the body was not sealed at the factory good enough and as...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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.