If the air conditioning is on it makes a loud squealing noise. We've changed belts wigh no kmprovement
My car has 2282452 miles.
My car has an automatic transmission.
Hi there. Depending on the engine and type of car you have, it may change the diagnostics. I suggest checking the a/c belt tensioner for proper tension on the a/c belt. If the tension on the belt is okay and the tensioner is okay, then the a/c compressor is causing the belt to squeal due to a locked up compressor. If the noise goes away when a/c is off and comes back with a/c on, then the compressor will need to be checked to see if it is locking up. This is due to having a bad compressor or a blockage in the system causing the high pressure side to be blocked. The condenser or expansion valve and drier may be blocked. I recommend having a technician, like one from YourMechanic, inspect the air conditioning system and replace any failing parts.
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