Mechanic just replaced my timing belt, timing belt tensioner, water pump (new, not rebuilt), and 2 serpentine belts. Now my car squeals about 10 seconds during startup, then stops. It only occurs during startup, and usually only after it has been sitting for a while. If I start it, it squeals, then stops, then if I start the car again in a few minutes, it usually will not squeal.

Brought it back to the mechanic and he double-checked the top serpentine belt and tightened it just slightly because did not want to overtighten it, but said it looked fine...so what could it be? Do brand new belts need a breaking-in period? Is there an easy way to "hear" where it is coming from? Thanks!

 

mine does that too. it might be from condensation that forms on the belt then after the cars warms up and the condensation dries up, squeaks is gone.

 

a friend of mine was i college and poor... helped her out by replacing her drive belts...she got the cheap ones from napa and squeaked during start up....had to adjusted then three time till the noise stopped...also, the tech may have gotten coolant on the pulley, and contaminated the belts....

 

Wow, interesting you said that because my coolant was flushed and he mentioned maybe antifreeze got on it....but he said it should go away after driving it for a little while. But you say contaminated it, is antifreeze on the belt a permanent problem or will it go away eventually?

 

Coolant on the belt is only a temporary problem. You can flush it with soapy water and that should get rid of any remaining traces of coolant. To really diagnose the cause of the problem, you can use an automotive stethoscope. They're only about $15. My guess is that you might have an idler bearing just starting to go. With a new belt, you're getting much better traction. If the bearing is rough, it will fight the spin on the new belt. Whatever you do, do NOT use belt dressing!!!!! Belt dressing sprays a sticky substance on the belt to eliminate slipping. That will get rid of the squeal--temporarily. After that, the sticky stuff will pick up all the road grit and start grinding away at all the pulley and the belt. In the end, you will have far more problems than you started with.

 

This is good to know.

Pardon me, while I hide the belt dressing in the trash can.

 

If you had a serpentine belt, there would only be ONE belt that drove all the engine accessories. What you mechanic tightened was the alternator/compressor belt. When you first start your car in the morning the battery is slightly discharged form sitting overnight. If the belt is loose, old, or of poor quality, it may slip and squeal as the alternator puts more of a load on it as it attempts to charge up the battery. If the battery is old, weak, or crappy this effect will be pronounced. If it continues have your mechanic check your battery.
A failingtiming belt idler bearing will not make a classic belt squeal noise. A correct timing belt job should have replaced the idler and tensioner bearings, as well as the water pump, cam and crank seals.