Hissing when accelerating

[audioqueso]

Lately, I've been hearing a hiss ONLY when I accelerate. I checked the connections in the engine bay, but it sounds like it's right along the driveshaft. I'll be cruising down the road at 40mph, and when I press on the accelerator it sounds like I'm using nitrous. It has that same exact hiss. I don't have any nitrous installed in my car (and if I do, it sure is slow LOL). And this sound is with the A/C as well. I let go of the gas, and it goes away.

I don't think it's effecting performance right now, but I really don't recall if this was there before, or if it's something new that should be addressed before it causes any other problems. Any ideas?

 

[ACSPONY]

I took ouy my air intake silencer and changed the filter to a better flowing one than stock and I can hear it suck in air when I accelerate. I know that's not near the driveshaft but I don't know of anything down there that would make a hissing sound

*bump*

 

[Tom in Tacoma]

If it's alongside the driveshaft I'd bet it's an exhaust leak. With the engine running - go underneath and check it out.

 

[audioqueso]

But it's not when the engine is running, it's when I'm feeding it gas. I have ramps I can put my car on, but I'll have to have someone give it some gas while I'm under. Is that even a safe idea?

 

[tomustang]

Lately, I've been hearing a hiss ONLY when I accelerate. I checked the connections in the engine bay, but it sounds like it's right along the driveshaft. I'll be cruising down the road at 40mph, and when I press on the accelerator it sounds like I'm using nitrous. It has that same exact hiss. I don't have any nitrous installed in my car (and if I do, it sure is slow LOL). And this sound is with the A/C as well. I let go of the gas, and it goes away.

I don't think it's effecting performance right now, but I really don't recall if this was there before, or if it's something new that should be addressed before it causes any other problems. Any ideas?

But it's not when the engine is running, it's when I'm feeding it gas. I have ramps I can put my car on, but I'll have to have someone give it some gas while I'm under. Is that even a safe idea?

well, when the hell is it??

 

[audioqueso]

well, when the hell is it??

What? I said it's when I'm feeding it gas. It's not when the engine is just running. I have to press the accelerator to make that noise. Is it that hard to understand?

 

[danny g]

intake leak? You wouldnt get that near the D/S though. I have a small leak on my intake and i get a hiss/whistle when accelerating. It could be anywhere but i cant locate it. Just a tad annoying undet WOT.

 

[stripped302]

Audio my car is doing the same thing.Its driving me crazy. Do you have a cold air kit? I think thats what my problem is cause it didnt do it before then,but I took the screen of because it wasnt sealing right when Connected to MAF to the elbow that goes into the fenderwell. Sorry dont mean to hijack your thread I just have the same problem.

 

[FallenPhoenix]

I made a post about this a while back, still haven't figured out what it is. I've still got the paper filter and stock intake. My JLT CAI should be in pretty soon, maybe it will change the noise if nothing else.

I haven't really noticed the hiss much lately though, maybe it's because I can't hear it over the exhaust

 

[stripped302]

intake leak? You wouldnt get that near the D/S though. I have a small leak on my intake and i get a hiss/whistle when accelerating. It could be anywhere but i cant locate it. Just a tad annoying undet WOT.

How do you tell if you have a intake leak?and doesnt it cost some performance?

 

[Tom in Tacoma]

Even if you have an exhaust leak that can only be heard when you're accelerating - you'll still be able to detect it with the engine at idle when you're under the car. Just run your hand along the exhaust system till you feel the pulsing of air. If need be have someone that can raise the RPM.

I'm still betting it's an exhaust leak.

 

[myponyrocks]

did you recently install a T/B and Plenum? Mine does this but only under hard acceleration... I havent figured out if its just more air flowing through or if its the TPS hissing at me?

 

[audioqueso]

Well, the hiss is completely transparent if I lift the car and try to listen for it. I tried reving it up a bit while parked to hear it. No hiss. I lift it up on ramps and crawled under. No hiss. Used tubing to centralize the hissing. No hiss. Tried to "feel" for air pressure coming out. Nothing. I had someone rev it up a bit while I was under, but still no hiss. I set the car down and drove around the street. Sure enough, the hiss is there. The only difference in sound, though very slight, was from the first cat on the passenger side. That's also where the hiss appears to be coming from, but I couldn't feel or hear any hiss while I was under the car. Any help?

 

[droptopsnake01]

I'm thinking exhaust leak also.. I've heard of some weird s*** b/c of exhaust leaks

 

[audioqueso]

Ok, well you're thinking like everyone else, but how do I find it if I couldn't hear or feel it?

 

[droptopsnake01]

Just get it up in the air and tighten everything up.

Do you have a aftermarket exhaust?

 

[audioqueso]

There is no air coming out of any area. I said that already. So I'm not just gonna go and start tighten every single bolt under the car. And no, my full exhaust is stock.

 

[Route666]

How about tightening every exhaust junction? That can't be too hard. Hell even tightening every nut and bolt under the car wouldn't take so long. You could just ignore the sound, if you don't want to do anything...

 

[FallenPhoenix]

I'm pretty sure this is an intake 'problem' When I installed my CAI last night, I took it around for a while and the hiss was noticeably louder but still under the same circumstances.

 

[Tom in Tacoma]

If you want to find an elusive exhaust leak - try this...

Using a rag to protect hands, have a couple buddies cover the exhaust pipe tips, sealing them off. Once the pressure builds up in the system you'll quickly locate any leaks.