Ok, I just got my car back today after having the clutch slave cylinder replaced and heard a hissing type noise under the car. It's not a constant hissing noise though. It kind of sounds like a low pitch nitrous purge. I don't think it has anything to do with the recall replacement. I'm thinking exhaust leak or fuel pump. Any ideas?

Only mod under the car is the HKS exhaust.

 

are you sure it isn't your jwt intake.

 

any fluids on the ground?

 

Yea I checked that. Hasn't happened before. No noise there. Almost have to put my head at the bottom of the car to hear it.

 

ummmmmmmmm ok. i would probably get someone to rev the engine with you outside of the car. Make sure who ever you get to do this does not have the car in gear, lol. Just trying to keep the 350z community safe.

 

Did that also. I'm going to try and get it on a lift shortly so we can get under the car.

 

good luck with your car im sure you will figure it out. I'm begining to think you might have an exhaust leak!

 

Disconnected vacuum lines?

 

hmmm....didn't think of that...I'll check

 

...or maybe a seriously ticked off snake!

 

i was just gonna say that

 

Going back to the dealer today. I'll post an update when I get back.

 

I have recent clutch issues. I also have this his which I dont believe its and exhaust leak. Im woundering if its coming from or has to do with the tranny

 

Start your car, then crawl underneath and spray soapy water on all your exhaust joints. Look for bubbles or obvious streams of air.

 

Of course when I take it to the dealership the noise stops. It hasn't done it since and hopefully never does again. I'm going to check it out again tomorrow when I put my test pipes on.

 

You sure it's not the flywheel? Sometimes I get a hissing sound just before I hear the dual-mass knock against itself.
Also, I can hear a hiss while in the driver's seat. I think it's the fuel pump.

 

I got the sound as well after changing after market header and test pipe. I spoke to a few mech, they said its normal for free flowing exhaust.

Anyway its,
Fujisutbo Header
Mines Test Pipe
HKS Y Pipe
Apexi N1 Muffler

 

I got the sound as well after changing after market header and test pipe. I spoke to a few mech, they said its normal for free flowing exhaust. The hissing sound comes when RPM is dropping, be it engine braking or no load reving.

Anyway its,
Fujisutbo Header
Mines Test Pipe
HKS Y Pipe
Apexi N1 Muffler

 

It sounds like it could be an exhaust leak!!!

 

Noise is gone. Not sure what it was. Hope it doesn't come back...