viktahhh

Im getting a strange noise coming from my intake over 4000rpm it sounds like a high pitched vibration of some kind. Any ideas what it could be?

Railmaster.

Remove the air filter lid and filter cartridge, if the sound still shows (sounds), there may be some lose parts on the varioram system, they are plastic and known to break.

I'm just guessing...

AOW162435

Check the inside of the fan housing for scrape marks. If the fan is contacting the inside of the housing, you will hear it.

Worn alternator bearings and/or a worn fan hub bearing will allow the fan (constantly under tension from the belts) to eventually touch the housing.



Andreas

pp000830

If it is a whistling like sound most any number of things can make it. Have someone cycle the throttle for you while you stand behind the engine with the lid open and with a short piece of garden hose used as a stethoscope to localize the sound.
Andy

k722070

when the bearing in the fan belt sensor dies it makes a very pretty high pitched vibration noise that varies with rpm.

viktahhh

it happens when the car comes on cam at about 4000rpm ill try to record it and check out what you told me to

viktahhh

it happens when the car comes on cam at about 4000rpm seems like something in the intake - my car is a pre vario ram 1995 model

viktahhh

its a pre vario ram car 1995 model

Ivan J

Perhaps it has something to do with the resonance chamber, which is the lower portion of the air distribution manifold on the non-vram intake. I don't recall the rpm at which the valve changes positions, perhaps someone else can provide that info.

viktahhh

I may have to check this out - it's driving me nuts...i mean every porsche owner spends 70% of their time tracking down noises