Squeling belt but only a year old

toyota
sienna
belts

#1

I have a 2005 Toyota Sienna LE mini van that has a belt that squeals sometimes when I turn on the air. It is just over 1 year old and the mechanic that installed it and I parted ways when I caught him cheating us (and others). Took it to the dealer says they can’t do anything as long as they can’t hear the squeal and that the belt “looks okay”.



I asked about the tension going bad but they said the tension looks okay and it tensions automatically.



I had it sprayed with belt dressing and there was no squeal for about 2 weeks.



One belt runs everything.



What is causing this, what can I do, and is the belt going to break?


#2

It might not be the belt. It could be the clutch plates engaging on the AC compressor. The pulley that runs the compressor is always turning, since all pulleys are run by the serpentine belt. When you turn the AC on, the clutch plates engage to turn the compressor. Have you had any AC work done?


#3

If tension is good and your AC compressor is ok, you should get a new belt.


#4

Maybe the mechanic that cheated you never actually changed the belt.


#5

I thought of that but the belt was changed. It could have been a used belt but definately not the same one I went in with.

Thank you both for the help.


#6

We went through the squealing serpentine belt problem on our 2003 Toyota 4Runner when the car was brand new. The dealer put three new belts on the car and the problem persisted. In our case, the belt would start making noise after we had driven the car a couple of miles. The second time the belt was replaced, it wasn’ done right and the crankshaft oil seal was pulled out. When the third belt did the same thing, we told the dealer to either fix the 4Runner or buy it back. The problem turned out to be a weak belt tensioner. Needless to say, I lost confidence in the dealer and the 4Runner has gone to our independent shop since.