sptschoice

hi Guys drove my car to first time since the winter and I'm hearing a high pitch whining sound when I'm cruising around 70mph and up.I only hear it when I press the gas pedal goes away when I release...any idea?

Viperbob1

Lost my whining sound as a part of the divorce.... Do not suggest you do the same...

Where is the sound? Stereo? Engine compartment?

sptschoice

I'm hearing it towards the back the engine compartment

Linnm

Alternator?

CalvinC4S

^ probable cause

shadow993

Loose or dry belts?

sptschoice

if i it is the alternator shouldnt I hear the sound when the car is idling?

Robin 993DX

Could be the belt sensor roller, the plastic breaks up easy and the bearing can sometimes run dry and make noise.

pcarhombre

I had a similar noise. Turned out the plastic intake piece that sits on the fan housing had a big crack in it. Does the whining increase and decrease with throttle and then go away at low revs? Relatively cheap fix.

sptschoice

yes exactly...I will check the fan housing....

pcarhombre

Bump for update. What did you find?

sptschoice

didnt get a chance to check due to my work schedule I will today before the rain comes

Waldteufel

It sounds like your fan is contacting the composite shroud. I had that problem a few years back and I was advised I needed a new shroud because it had become distorted because of the high heat in the engine compartment. Coincidentally, it first started making that singing noise when it was in the upper 90's that summer.

I'm glad I didn't spring for an expensive shroud replacement as late last year I had a new fan installed along with new bearings on the fan and alternator shafts. Evidently, the worn bearings had allowed for too much deflection via belt tension. Plenty of clearance now. My fan had apparently developed a few creeping hairline cracks on three blades and one day the centrifugal forces at a bit over 6k RPM caused two of them to fly off. It made a helluva noise, but luckily no damage to anything other than a couple of belts.

No idea why the blades developed the cracks other than from possible stress from the light contact with the shroud, but the broken surfaces showed a pretty even coating of engine soot that had crept in over time.

SeaJeff

This thread is really timely for me. I'm still discovering my new 993 but it too makes a sort of whine. In my car, it very much sounds like a stereo ground loop/buzz, but the stereo is off and its definitely coming from the rear engine compartment.

I don't recall this sound in my C4S, so I was wondering if it had something to do with the Turbo. But after reading this thread, I wonder if it is something else. I'll need to do some more listening (acoustic research ) and follow this thread.

e9stibi

Belt tensioning sensor? I just replaced this part.