Hissing????

[airbrat]

I went to the mall yesterday w/ my daughter and noticed when I stepped out a very distinct hissing sound coming from underneath my car. At first I thought I had a tire leak but the moment i removed the key from the ignition the hiss was gone.

What could make such a noise? the hissing was so loud I had a hard time finding the source. any thoughts?

 

[candela]

a boost leak easily could. If it was in the car I would check to make sure all the connections to the boost gauge are secure/sealed up properly

 

[jbillakdsm]

Could be the flex section of the DP, mine hissed like a snake till I replaced it.

 

[airbrat]

Originally posted by jbillakdsm
Could be the flex section of the DP, mine hissed like a snake till I replaced it.

thats a good idea! thats just about where it sounded like it was coming from!

 

[jsigone]

Fuel pump... Mine does the same. I was tripping one day and heard it, foolowed it back to the fuel tank, car went off and so did the noise. I though it was the tires too, but it's just the FP whining, What FP you have in there? I have a Walbro 255.

 

[airbrat]

well I went out to my car this morning and when I turned on my car the hiss was gone! wtf????

I know its not my fuel pump cuz I hear that damn thing all the time.

now I'm really baffled!

 

[Omega]

I still be the exhaust. When it heats up, the hole gets bigger which is when you hear the noise. Let it warm up and take it for a spin, I am sure it will be back.

You could also look around the exhaust for black sooty deposits, that is another tell tail sign of a leak.

 

[jbillakdsm]

Yeah, the DP can leak and then stop and then start again if it's in the flex section due to the way it's flexed at the time. Inside there are these acordion-like pieces that fit up against each other and when they ster to rust out, they can still seal up at times. When my car was cold it didn't leak, but as soon as it got hot it was back. Eventually it got to the point where if I got out and pushed up on the DP it would stop and as soon as I let go it would leak again.