Hissing sound from left side

[Lofwyr]

Hello Gentleman,

I need some advice here.

I am getting a hissing sound from the left side of my 91 NSX. It started the other day on a 340 mile drive up to NC. The weird thing about it is that it only makes the high pitched sound at a very narrow throttle range, about 1/8th in, but then when you press the gas furthur, it stops, and if you let off the gas a little, it stops...

I do have a Finstar DTM exhaust and a K&N drop in filter on the car, but these were installed about a month ago and the noise just started occuring 2 days ago.

Could this be an exhaust leak or something? Performance is completely unaffected, the car drives exactly the same as before.

I'm going to be taking the car into Ed Voyles Acura to get my new 18" rims installed (whole 'nother story) this week, and I'm going to have them check the noise out since they installed the exhaust and intake, but I want to get some knowledgeable feedback before I go. I have checked the FAQ and the archives and found nothing to help me with this issue.

Any ideas?

- Sam
91 Black/Black 22K Miles
Finstar DTM Exhaust
K&N Filter
Dali Street/Race Bars
Custom Stereo

[This message has been edited by Lofwyr (edited 02 September 2001).]

 

[SpeedDemon]

I've had a similar noise/similar symptoms for a few months now..

I was told it could be the solenoid for the gas tank/vapor system bleeding off pressure..

Please post (or email me) if/when you find out what the problem is and how to fix it.. Thanks.

Marc
P.S. Lofwyr? Shadowrun fan, ey?

 

[Lofwyr]

So yours only does it at that very narrow throttle range? It's really weird.

I will make sure to post the answer if and when I find it out.

BTW, I was a Shadowrun fan about 8 years ago, I've kept the handle ever since. Used to run it on my license plate.

- Sam

 

[Lofwyr]

Anyone have any more info?

 

[DutchBlackNsx]

Are you sure it's not the throtle-valve youre hearing???
With standard air-intake, you'll only hear when switching off, with aftermarket intake you can hear when driving, with open air-intake, it's getting anoying....


Dutchy

 

[NSXLNT]

I just installed an RM Carbon Fibre Intake a few weeks ago and now have some hissing just as you describe-I'm sure it's just the throttle sucking in air, part of the enhanced
sonic benefit of an aftermarket intake.

 

[Lofwyr]

Hmm,

I suppose it could just be the sound of the intake. Why would it have taken about a month to start making the noise?

 

[DutchBlackNsx]

I noticed it with my standard intake after more then a month.
Do this:
Stand still, rev the engine, switch the engine off, open youre door, and notice the suction when the engine stalls. It's really there for a few secs.
Do it again, now with youre foot close to the accelerator. When the engine stalls, and you hear the suction, press the accelerator.

I installed the RM-carbon fiber air intake with cold-air option a few weeks ago. With a little practise you can get the sound of an blowing-off turbo when shifting gears.

Dutchy

 

[Lofwyr]

I think it's just the intake. Well, at least I can fool myself into thinking I have the Bell TT kit now. Brrrrr, shift, pssst, tire squeel, grip, hit the gas!!!

fun

- Sam

 

[SpeedDemon]

Originally posted by Lofwyr:
I think it's just the intake. Well, at least I can fool myself into thinking I have the Bell TT kit now. Brrrrr, shift, pssst, tire squeel, grip, hit the gas!!!

fun

- Sam

Grin - if anyone in L.A. wants to record what a real one sounds like (so we could put it up on the website) I'd be happy to take 'em for a ride.

Sam - Glad to hear your problem is "solved"

. I still read Shadowrun but I think the series is discontinued now?..

Marc

 

[Lofwyr]

Demon,

Is that what your noise is too, or do you not think yours is the intake. I'm still going to have my mechanics check things out later this week whenever I goto the shop to get my wheels installed (when Dali gets me my spacers).

Shadowrun does rock, but I stopped reading the books a long time ago. I read mainly Tom Clancy these days, I should go get a old Shadowrun book out sometime.

- Sam

 

[Edo]

I seem to find that after 1 month or so of driving the filter gets dirty enough that it starts to hiss a bit. I think it has to do with the way the air flows (less or more?) when it gets more dirt on it.

I find that this condition is MUCH more exaggerated with my RM CAI. The K&N FIPK didnt seem to make too much hissing for me.

 

[SpeedDemon]

Originally posted by Lofwyr:
Demon,

Is that what your noise is too, or do you not think yours is the intake.

Hi Sam,

Whatever my "hiss" noise it, it's probably not the one being described (relating to the air filter). I have a dual K&N intake, with a filter located in each rear fender and not in/near the engine compartment where the hiss seems to come from... I think it's probably a solenoid (Mark B identified the solenoid as being the likely culprit). One day I'll dive deeper into this & see if I can find a solution, but for now it's not really as noticeable (it's no longer a "new" noise)

.

Marc
97 NSX-T Twin Turbo