Wheelman916

My car has been making a whirring/groaning noise.

Noise is loudest after a cold start. Quiets down significantly within 3 to 4 minutes.

Noise does not change whether clutch is engaged or disengaged.

Noise follows and increases with engine RPM until quieting down after the initial 3 to 4 minutes.

I'm guessing maybe power steering? Possibly A/C compressor clutch or pulley bearing? Or smog/air pump? But I honestly don't know. It sounds accessory/pulley related to me... but I'm no mechanic. Far from.


Car info: 1995 Z28 M6. 79k miles. Pretty much stock.

realistyc

iTrader: (5)

i would remove serpentine belt then start the engine, that would tell you if its base engine. spin all pulleys by hand to see if you can feel any roughness in any pulley bearings. if it was power steering the pitch of the noise would change by turning the wheel usually. my guess is water pump or alternator. good luck with it

1BurnedZ28

Right on the money with this suggestion minus starting the motor, don't start it until you've spun everything by hand with the belt off.

realistyc

iTrader: (5)

i think he gets the idea. spin pulleys while engine is not running with belt off. then start the engine with belt off to see if its base engine etc..