Q: Rattling noise inside engine when AC/Heater/Air on

asked by on

Hi there!

For the past maybe year or so I've been having this weird rattling under the hood that happens when either the AC, Heater, or if I'm 'circulating' air (not on hot or cold air). The noise appears when the car is turned on after being used (not cold) for about 5 seconds and goes away. I had a listen to where the noise appears to be coming from and it sounds as though it's coming from the top left corner behind. The sound almost sounds like a rock in a can being rattled.

Any help would be greatly appreciated! Thank you!

My car has 154000 miles.
My car has an automatic transmission.

You may have a serpentine belt or tensioner issue and may need to have them replaced but first should have a mechanic like one from YourMechanic diagnose the problem to verify the noise.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Rattling noise inside engine when AC/Heater/Air on

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: Engine hot, difficult shifting, shutting off

Hello there, thank you for asking about your 1987 Oldsmobile Cutlass Calais. A common problem that can cause stalling is a stuck torque converter clutch. This device connects the link between the engine and transmission, but should slip some when...

Q: Loud cracking noise underneath them can have a nic loud cracking noise underneath then car almost dies out

Hey there, thanks for writing in about your 2007 Lincoln MKX. Unfortunately, without hearing the noise or conducting a few tests firsthand, it is not possible to determine the cause of your concern. Since you say you are hearing the...

Q: When I make a turn both ways I hear a knocking sound, I have already changed, cv shaft, lower control arms and ball joints.

It is possible that you can have some free play in one of your inner or outer tie rod ends. I would recommend having your inner and outer tie rod ends inspected by a qualified professional to determine if they...

Related articles

What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.