Steady Whine In My Engine Compartment

Hello, from my humble experience these are the basic things to check:

1. the serpentine is loose or/and needs replacing. Whine is caused by slipping belt due to increased load on alternator. That would explain the whine after first of the day. It could be also the battery that is weak. Sometimes even helps to put very small amount of grease on the belt. Motor oil from dipstick would work.

1. One of the serpentine belts is waving good bye.

2. Alternator is going.

1. Unlikely AC compressor is playing. The automatic AC would have to feel the need for AC compressor right after the startup which can happen if sun light is detected and exterior temperature is above 18 Celsius.

Try to observe it. Like if you turn on lights and wipers is it going to whine etc. I hope that it is most likely just the serpentine belt or battery.

Good Luck, Radek

Valjean wrote:

Sounds as if the idler pulley bearings are going. Get this fixed soon. When it fails, it will throw the belt. If you try to drive with a thrown belt (no water pump) the engine will overheat and likely blow the head gasket and possibly warp the head. Big $$$.

To troubleshoot the problem, remove the serpentine belt and start the engine. Only run it very briefly, just long enough to determine that the noise is gone.

If so, (kill the engine first ;-) ) spin the individual pulleys to see if you can feel which one is bad. It's possible that the alternator, waterpump or AC are the offending ones, but experience shows that it is more often the idler or tensioner pulley. These are cheap and should be replaced prophylactically at about 60-80k intervals anyway. Change the serpentime belt at the same time.

-Fred W