2000 Porsche C4, when at idle theres a weird whinning sound that appea

[Johnny-5]

I have a 2000 Porsche C4 that has a weird whinning sound that appears to be coming from the front. It kind of sounds like a radiator fan but I dont think it would make a noise like that but I could be wrong so Im asking you all for some advice and help.

When driving it appears to be fine and cant hear anything but when at a stop it kicks on and shortly after driving off it stops. It appears to be only happening when its warm but Ill have to confirm that. Also trying to figure out if its coming from the front or end.

Has anyone encountered something like this before? Is there like a water pump thats up in the front of the car that could be making a sound like Im describing? Could the radiator fans make a noise like that? I have a tiptronics so I believe there are 3 radiators on this car can anyone confirm? And if so where would they be located?

Thanks for any help.

Johnny

Edited February 7, 2010 by Johnny-5

[dammad]

Check if it makes the noise with the AC switch on too (when idle).. The fans (all three I believe) will run on low speed. Of course it could be a problem on the high-speed side but this would seem to be a simple check.

[wvicary]

Check to see if it's coming from the fuel tank vent valve. Listen carefully near the gas cap.

[Johnny-5]

Check if it makes the noise with the AC switch on too (when idle).. The fans (all three I believe) will run on low speed. Of course it could be a problem on the high-speed side but this would seem to be a simple check.

I believe I tried it on and off and at a stop I can still hear it. Ill confirm everything tomorrow as I didnt drive the car today and got home late today.

[Johnny-5]

Check to see if it's coming from the fuel tank vent valve. Listen carefully near the gas cap.

Ill double check everything tomorrow but I believe its coming from the front passenger side. Where exactly is the fuel tank vent valve anyways and what exactly does it do?

[PTEC]

If you believe its coming from the radiator fans you could try pulling the fuse for the fan and seeing if that stops the noise. There is a fuse for each side fan, I believe they are C8 and C10. They're 30 amp fuses if I remember correctly.

[Johnny-5]

Ok I havent been able to really verify where its coming from. When Im standing outside the car it never seems to happen. It didnt happen for a few days and than earlier when my girlfriend was driving it she heard it again at a street light. I had her drive up the drive way and was trying to listen and nothing.

PTEC do you happen to know where the fuses are and which one is for the passenger side? I was also wondering how hard is it to access both radiator fans so I can see if they are bolted correctly, etc??? Could someone provide detail instructions.

Thanks again!

[dafink]

I had a similar problem with my 996 recently, turns out it was the evap pump in the gas tank kicking on. I happened to have a clog in my line which was blown out, but this type of problem can range from a $10 gas cap to a total system overhaul for a couple of g's.

I did have a check engine code pop up that allowed me to diagnose it fairly easily, but it took a few weeks for the light to pop up.

quote name='Johnny-5' date='Feb 11, 2010 - 12:30 AM' post='167983']

Ok I havent been able to really verify where its coming from. When Im standing outside the car it never seems to happen. It didnt happen for a few days and than earlier when my girlfriend was driving it she heard it again at a street light. I had her drive up the drive way and was trying to listen and nothing.

PTEC do you happen to know where the fuses are and which one is for the passenger side? I was also wondering how hard is it to access both radiator fans so I can see if they are bolted correctly, etc??? Could someone provide detail instructions.

Thanks again!