When standing in front of my 81,000 mile '02 LS430 while it's running, I hear a slight whine. It's not noticeable inside the car. Is this normal, or is it a precurser to some kind of bearing failure like in a pulley or alternator? I'm sort of a nut when it comes to noises, so maybe I should just ignore this unless it gets louder.

 

My LS has similar miles as yours and I also have a slight whine or chirping sound at idle. I suspect either a worn serpentine belt or idler pulley bearing. I plan on having it checked out soon when I have the timing belt changed.

 

If the whine was not there when the car was younger, something is wearing and will need attention. Some areas to check:

1. Power steering- turn lock to lock if you hear the pump more at full lock, check the condition and level of the PS fluid.

2. A/C with it on does the compressor make any noise excessive.

3. The idler on the serpentine belt, easy to disconnect the belt and spin this idler to check for any obvious runout/noise.

4. Alternator

5. Water pump and or other portions that are related to the timing belt.

 

I had it. Turned out to be fan motor. It's not rare for these to go as it turns out. And it can be expensive if bearing fails and propeller flies onto the radiator. Big damage possible.
To check if it's fan motor - switch A/C to OFF and have a listen again.

ps. fan motor is 200usd. ouch.

 

Nope, it's not a fan.

 

I had a whine that would increase with engine speed, it was the bearing in the alternator pulley. It was loud enough that I could easily hear it from inside the car. Replaced alternator and solved the problem.

 

It's probably a pulley bearing.

 

I have a similar whine that's more noticeable when the temperature outside drops and I first start the car. It's not there once warm. I feel it's the power steering pump as it gets louder when I turn the steering wheel. I'm planning on doing nothing at this time as it's not very noticeable and I don't do long distance driving.

 

Turning the steering wheel doesn't change the sound of it on my car. If I had to make a wild guess, I would say it is an idler pulley or alternator bearing. Maybe it's nothing to be alarmed about. I'm taking it on a 900 mile trip in a couple of weeks. I may get a Toyota tech to listen to it next week. Everything works perfectly on this car. It runs and drives great. Timing belt and serpentine belt were rplaced by a Lexus dealer 3,000 miles ago.

 

I have a stethoscope gizmo I purchased on line that helps to pinpoint engine noises. It goes in your ears and has a long thin tube to place on suspect areas. You might want to invest in one to help you pinpoint the area. It was only a few bucks.(In the old days I used a broom handle)

 

its crying to tell u to mod it

 

Well, it does not make the noise when the engine is hot, only when it is cold, like the first start after sitting for several hours. Maybe it is the serpentine belt. It's fairly new.