Howling - 1991 Ls400

[aburas]

I have a 1991 LS400 that recently has started to make a slight howling

noise. I thought of the usual suspects like bearings (happens even when

totally stopped), tranny (not associated with shifting gears, sounds

the same when in any gear or even at a total stop), power steering pump

(No winding whatsoever when turning sharp in a parking lot...and no

leaks).

Has anyone had a problem like this? I cannot even isolate where

exactly it is coming from...its not an exhaust type sound. I wonder if

it could be the rear differential? Has anyone had any experience with

anything like this?

[Steve]

cannot be rear differential if it still whines when car is stopped.

do you have a worn pulley belt?

thrust bearing worn? (not sure if these exsist on the LS)

[bjkilpa]

on my 1991 LS I had a bad Alternator causing a Howling/roaring/screacing (i cannot remember) I originally thought it was the power stearing pump, but turned out to be the Alernator bearings.

[aburas]

It seems like the only time you can hear it is from inside the car and not under the hood. It is kinda like it is coming from the bottom of the car. Could it be from the tranny? It doesn't seem to go away tho when you are just in park...it stays the same if you are stopped and move it through the gears. You would think it would changed depending on speed or on gears if it was the tranny.

It also is not affected by whether the AC is on...and I had my power steering pump checked out about a month ago it is ok.

[ko90ls]

if the sound is comming from under the car it would be a missing O2 sensor? this is just a complete guess but from the sound of the problems it may be. the o2 senser screws into the exhaust pipes so a missing out would probably make a howling, hollow type sound. just a thought

[skyking]

Can you cycle the air conditioner on and off and change the sound?

[Monti]

I did, I was my power steering pump. I paid $120 for the pump and

$145 to have it put on.

Good luck with yours.