FCSFrank

91S4 with 105k,

Started hearing a new, strange noise several weeks ago. Not sure where is coming from I haven't really checked yet. looking for direction...

the noise as I hear it - sitting in the drivers seat, start the car and I hear this sound that sound like someone has a drill running and is letting the chuck rub on part of the car. no vibration, just noise with a hum that matches engine RPM and that increases with engine RPM.. it doesn't get any louder, the speed of the noise just increases. might be coming from front of driver area.

hope this description is sufficient for thoughts.

Thanks

Nicole

Have you heard the noise with the hood open? Sometimes noises "travel" and fool you to believe they originate in different locations.

If you think it's the front left, it would be the alternator or power steering pump.

It could also be a torque tube bearing.

When was the last time you checked and released flex plate pressure?

You could take a short piece of hose - like garden hose or vacuum cleaner hose - then put one end to your ear, and the other next to the suspected sources of the noise. Be careful not to touch any of the belts, though! Once you hear the noise clearly through the hose, you have found the source.

Best of luck!

Mrmerlin

Before you run the engine anymore to diagnose the noise, I would do a flex plate check/crank end play check.
You can also get a piece of lamp cord wire stick it into the dipstick hole and then drip the oil onto some black cardboard go into the sun and look for metallic particles, if you see metallics then you may have a thrust bearing going bad ( you still need to check the flex plate)
If the flex plate checks out good then you probably have a TT bearing/ TC bearing going bad this reqiures the trans/TT to be removed , also replace the front pump O ring and the radial seal on the TC

FCSFrank

Thanks - good places to start..

anybody else have thoughts ???

thanks

Mrmerlin

do these first Frank

namasgt

Take Mrmerlins advice, check your flex plate before you run the engine again.

Nicole

My car has about the same mileage, and we have released flex plate pressure a few times already. Not much, but it could have become much, if we had let it go.

Other sources could be the timing belt and its rollers, or the water pump impeller grinding the block.

But I have never heard anybody report audible grinding noises from TBF or water pump failure.

Mrmerlin

Nicole there can sometimes be whirring noise associated with the thrust bearing/flexplate being loaded.
It usually sounds like its coming from the TT/engine area.( woo wooo wooo wooo wooo wooo)
The TT can also make a whirring/ rattle noise
The TC bearings make more of a whirring/ grinding noise.

Nicole just an FYI if you have found movement on your flexplate i would suggest that you check the rear pinch bolt, remove it inspect for damage then blue loctite it then torque to 66ft/lbs.
Then retorque the front bolt, usually when there is movement of the flexplate its due to a loose rear pinch bolt.
Or a front pinch bolt thats not tight.
But the rear bolt has to be verified first. removal of the rear heat shields is required as is dropping the rear exhaust a bit