Writern

OK. So I gave up. I have a 911/83SC wich sounds like a whining pig. It is the kind of sound that you hear from the fan belt when it is not tight enough: Occational whines. The problem is that the sound is still there when I remove the fan belt. And sometimes it is all gone for hours while driving. I tell you this is beyond my intelligence. Can somebody please guide me into the light?
Thanx in advance :-§

bones

Sounds like a bearing moving in it's casing, suspect the alternator bearings. I assume you aren't driving a lot without the fan belt attached? If it happens on the move it could be a wheel bearing.

Writern

Thank you for your reply!
No. I dont think it is the alternator. The sound is coming from elsewhere. I thought maybe a defect gasket from inlet or something.

emac

I agree with bones, look around the fan blades and see if you can see any fine powder, it will be metal. If that is the case your blades are hitting the fan housing and you will have to replace the bearing.

Ernie 81 SC

Writern

English isnt my native language, so maybe I have described it wrong. Here we go : If your fan belt is not tight enogh, you will hear an occational whining, that comes and goes periodically if you open and close the throttle. So when I let the car run without the fan belt attached the same noice appears. If it was a bearing, you would hear another sound.

Peter Zimmermann

Writ: I'm obviously just guessing, is your air filter housing tight with both straps in place? Intake air on an SC can sometimes produce noise similar to what you're describing...
Pete

emac

Writ:
Sorry for the above wrong information. I must have my head up my rear today. I failed to realize the fan does not turn without a belt !!

Well I tried.

Writern

Peter: I tried detaching the airfilter, but the sound is still the same. I could swear it even became louder.
emac: Dont worry. I have spent a substantial amount of years with my head at such places.

:-)

Peter Zimmermann

Writ: Are you new to the car, or have you owned it for a long time and this noise is new? Is it a Cabriolet? Cabs tend to have more pronounced "whistle" type noises.
Pete

Writern

Peter: No. I have had the car since 1997, so I know its sounds well. This sound came after an overhaul of the car/engine. It is a very carachteristic noice. Loud. It is in pace with the rotation of the engine. It is a sound that definitely should not be there. Once I thought about a valve that had been to tight fitted to the bushing. But obviously that wouldnt have lasted long... I have benn driving with the sound for 200 km, and it came and went. I was sure it was the fan belt acting up, but when it didnt go away using silicone on the belt, I tried to detach the belt. No change. The sound is permanent when car is standing still with engine running. After that I decided not to drive the car until I could figure out what it was.

Peter Zimmermann

Sorry, I don't think I can advise you to do anything but have the car towed to a trusted repair shop.
Pete

Dr. Dynamics

I feel stupid questioning the gods but...

I haven't worked on that area of the motor yet but in the 69 VW i had, if the flywheel was not shimmed correctly and you had a lot of crank endplayt, my damper would histle against the pump bolts. Is something there that might be of similar case, (I know the pump is not there JIC) any bolt or whatever, since work was done in the engine?

Dr. Dynamics

Another one !

My 951 is currently whining just a little due to overtensioning of the timing belt tensioner. Nah, but SCs are chain, right? But you also got those chain guides...

jimq

vacuum leak?

sick

Possible chain rails worn.Does the noise go away when you press the clutch?I suggest using a long screw driver to pinpoint the source.Take the metal end and place it on the engine and place the handle to your ear.Try probing the around the timing case covers with it.