dchan865

For the life of me, I can't isolate where this strange sound(seems like spinning metallic sound) is coming from. You can hear when car is idle and faintly when driving(the wind/engine likely drown out most of the sound). AC is not turned on. No other strange sound during cranking of the engine or turning steering wheel. I know its not normal, started about 15K miles ago. The rig has ~220K miles. Hoping that the problem may be the alternator or a water pump, I also had them replaced, along with some other parts during a timing belt job but that did not help. So in summary, the following was replaced:
H2O pump
2 idler for timing belt
Belt
Timing belt tensioner
Serpentine belt
thermostat gasket
Seals and gasket
Reman Denso Alternator
radiator(infamous pin hole leak)

Could it be the fan clutch, something related to power steering, or warn out bearings in a pulley? Other than the sound, car performs fine.
Any tips on isolating this would be great!

sound(generated when car is in idle) file is attached.

NTH

Are you talking about the high pitched hizzzz sound or the lower pitched sound faintly in the background? The lower pitched sounds like power steering pump but usually they whine much louder.

dchan865

Its more of a high pitched sound. I checked the power steering fluid and its at the proper level.
This sound like something I'd have to have a mechanic look at it and and isolate it.

chiph9

I can't listen to the file at work. Does it change pitch with your speed or with the engine rpms?
i.e. if you're parked and rev the engine, does it change?

Chip H.

dchan865

Good question Chip. When I rev the engine when parked or when car is moving, the sound does go higher and goes back down when I don't step on gas. Sound like a power steering pump issue?
When I don't step on the gas during parked and turned my wheel, I don't hear the sound increasing or noticed any power steering abnormally. Thanks.

chiph9

Try asking a friend to rev it while you listen under the hood to identify it.

Again, I haven't heard the file, but there were some people earlier this year with alternator whine. It's located at the lower passenger-side of the engine.

Chip H.

DiabloX22

Is it a high pitch winding noise or what do you mean by metallic noise? I was getting a noise that almost sounded like a aluminium can was getting spun around somewhere. Lexus ended up changing the AC compressor because it would get really loud when I turned my AC on ( I didnt pay for it, I also cannot go back to that dealer after a conversation with the police, LOL) Anyway, it turned out to be my drive belt tensioner.

dchan865

Hello DiabloX22, I had encountered a bad tensioner 3-4 years ago. It only squealed when i turn on the car. This time the sound is not the same as the whining sound is constant. It goes up as you rev up the engine and in idle. Well, finally took the rig into a mechanic and he found the idler pulley was defective(i spun the part and noticed the bearings were bad), not the power steering pump as he speculated. Now the rig is running fine now.

I6turbo

iTrader: (1)

Glad you found the problem. In the future, a good way to identify the source of a sound like this is to take the end off of a stethoscope tube and use the open end of the tube to hunt around for the source of the sound by putting the opening up close to potential sources. It works great and there is usually no question when you've located the source. The sound will get much louder when you've positioned the tube directly in front of the source.

Also, regarding idler pulleys, be aware that the aftermarket pulley(s) sold at Pep Boys, O'reilly, AutoZone, etc. for this engine do NOT fit this engine correctly. They do not have the correct offset and consequently are slightly out of alignment with the rest of the pulleys.