I have a 93 850 GLT, and lately I've noticed a high pitched whine coming from under the car, rear right hand side. It's been a very constant, one pitch for a while now, but yesterday I noticed it start to stutter in the sound. It would be high pitched, then low pitched, basically changing sounds. It's constant, though...the sound is always there...pitch changes or not.

The car is running fine. I've had no problems starting it, or anything like that, so is this normal? I assume it's fuel pump related, due to the fact of where the noise is coming from, but it doesn't seem to be affecting the performance. (Yet?)

Any ideas, know what I'm talking about, etc?

 

Is this noise present while the car is not moving or it comes only when the wheels are turning?

 

No, the noise is there the minute I start the car to the time I turn off the ignition. Doesn't matter if I'm moving or not. It's not a wheel or brake thing, I don't think.

 

Could be the fuel pump like you say. It could also quite possibly be a small exhaust leak