Hi all, I started my 2002 LS 430 yesterday. The revs seemed unusually faster for a cold start and there was an almost eerie high pitched sort of whining noise which went away after a short while after I gently pressed on accelerator. I switched off the engine then back on and it was no longer there. Car is parked indoors but it has been quite cold lately in Toronto. Anyone ever had this? Freaked me out a bit
Thanks for listening

 

Ok......on a cold start, the SAI pump turns on for a short time. It sucks in air thru it's tiny air filter. Perhaps the whining you hear is the result of air getting sucked thru a this filter.

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Thanks JacobsDad, I'll keep listening and watching..Car drove fine and noise didn't re-occur. Very sensitive to noise that can spell $$$$$..
Cheers!

 

Had the same noise this morning that went away after a few minutes. A very wierd high pitch whine. Did you ever resolve the noise and find out what it was?

 

Never had it again after that first and only time and hopefully it won't repeat. But we are in extreme cold again here in Toronto so will see if it returns

 

In extreme cold alternators can make some gnarly noises especially the brushes.

 

I did have to change my alternator mid-year so this may have been a possible cause but the failure occurred many months after I experienced the noise. So many variables that it's hard to isolate a specific reason and the older the vehicle the more likely for an issue to arise

 

I wouldn't worry about it, in very cold weather sealed bearings can be very noisy. Alternators, tensioners and the like. Alternator brushes in my Lexus buzz for about 10 seconds on a very cold start it sounds like something is going to blow up.

 

I can't say that cold weather was the factor here in Florida when the morning temp was near 70 degrees. Yes, it sounds like a bearing and it did go away within a few minutes. I guess I'll keep on eye on it and see if it returns. It's hard to stick a stethoscope in the tight engine compartment while the car is running. That brave I am not!

 

Plastic tube works well, if it gets caught in something rotating no big deal.

 

. I thought that old wooden broomstick method was also effective in finding bearing noises.

 

Seems to me that power steering pumps always make racket when they are fired up when it's super cold out. It got to -17F here in Colorado last night, which caused those exact symptoms you are describing when starting things up.

 

None of the methods are effective. I've seen many people try they declare X part is bad and are usually wrong, sound travels though the engine readily. A bad alternator is easy put a tube on that you'll hear the problem. Rest of the engine not so much.

 

I had a crazy high pitched whine once or twice on cold start then a almost a month later my alternator died while driving, this was literally a week ago. I am pretty sure it's the alternator announcing its imminent failure.

Toyota/Lexus PS pumps are always loud in general does not mean anything as the pumps especially on the LS430, SC430, GX etc is very robust and they seldom ever fail even with 0 fluid changes/no maintenance to them.