Whirring sound in a 996, tied to RPMs

[tomsitzmann]

Hi;

I jut bought a 1999 996 from the west coast. It had an amplifier and Dvd-Navi put in, and when I called the seller about the whirring sound, he said it was the stereo system and sent me an "RCA Noise Filter" .

That did nothing. So, I disconnected the amp's power. That worked... for about a minute. When I drove the car, the whirring sound came back, and it sounds like it is coming from somewhere in the front of the car.Maybe it also has something to do with the xenon headlights?? Why though would this noise be tied, all the time, to RPM? That is, no matter when or where, when you hit the gas, the noise pitch goes up (higher).

Also, while checking this, I had the car running and heard another sound, a distinct low buzz/whistle which sounded like it was coming from somewhere in between the front wheels.... this doesn't sound normal. Any thoughts on any of this would be greatly appreciated. Is there anything up under there (maybe the radiator?) that might make a constant buzzing noise?

Finally, and maybe this is connected to the second noise I am hearing somehow, when I hit the brakes, anywhere at all more than normally, the ABS kicks in, roughly. It seems very inappropriate for a car like this to ABS this quickly, but maybe that's just me. Im not standing on the brake, just when I use them somewhat sharply to brake quickly.

[perryinva]

Not the Xenon's..they have nothing to do with any noise. Noise is most likely alternator noise coming from speakers..maybe the Nav speaker. ABS should not come in easy...check air pressure and/or tire sizes..low pressure or mismatch size can cause ABS issues. Need a lot more info about your car before anyone else can guess.

[tomsitzmann]

Hi

Interesting, thanks.

The wheels are 19" 295/30 in the rear and 235/35 in the front. They look to be Carrera S wheels, the standard wheel size is 18"

They are huge, and i have noticed several spots where the tires have rubbed/burned into the plastic covers that house the wheel area.

So, they must be too big....

Ill continue to check on the noise. Where is the alternator in the car? in the front?

[phillipj]

The alternator is in the back (engine compartment). To the left below the oil filler tube. It that thing that looks like an alternator :rolleyes:

Just playin :D

Your radiators are located on both sides of your front bumper in front of each wheel. If you have Tip trans there will be a third one in the center.

I'd bet that your braking problems are coming from your wheels. I don't believe those 19's off the 997 will work on an early 996.

Edited January 3, 2009 by phillipj

[OCNYPORSCHE]

The buzz that is associated with your RPMs is definately attributed to your DVD installation. The RCA should work, but sometimes you need a filter for all of the inputs to the amp. That is typical alternator whine.

The second noise coming from the wheel and connected to your ABS is different. I agree, I bet the the 19s are causing the issue there.

[PAULSPEED]

You did not say if your car was a 4s. Check your CV-boots

for cracks or if broken.

Paul

[tomsitzmann]

This is a C2 Cab 1999, 6-speed.

Thanks to all. It has been a bit of an odyssey with this car since I bought it. It has had its motor replaced, and a few other things.

Anyway, I am still a little concerned about the buzzing noise in the front that is unassociated with the alternator or stereo.

But, the car runs fine and Ill just keep monitoring that.

Back to the wheels, yeah, it seems to me that they are really shoe-horned in there and the fact that the edges of the tires have rubbed/scraped and burned away some of the plastic wheel housings is pretty much a dead giveaway that these don't fit.

So, anyone want some Carrera S 19" wheels?? Or if anyone knows anyone/anywhere that has the 18" turbo twist or cup wheels, I ready to trade!

Thanks

Tom

[cyclocross]

This is a C2 Cab 1999, 6-speed.

snip

A 1999? It appears to have 2002+ headlights and front bumper cover. Looks as if the previous owner added a lot of mods to the car before it was sold.

[tomsitzmann]

Hi

Yep, this is a 99. Yes, it had a new front bumper and lights.... not an "orginal" 99 by any means.