On the very very far right side of my car, there is a hissing sound that is DIRECTLY proportional to how hard i am on the gas. Very prominent when climbing a hill without kicking down any gears (so the engine is still quiet). Passenger can not hear the hiss with their left ear either. I will try and get a video; my first attempt failed to capture the sound, as far as i can hear. I'll try again tomorrow.

So far i have been suggested that it could be: exhaust studs, vaccuum leak, or my alternator dying (? got me?).

Point is, regardless of engine RPM, the sound gets louder just by me pushing the gas pedal, not by an actual increase in RPM. I can be using plenty of gas up a hill while losing speed slowly and hear the sound loudishly, and coast down a hill picking up speed while hearing no hissing at all.

Ideas?

 

loose vacuum hose?

 

whichever one would be closest to the passenger side? would that also explain my highish idle that dips and jumps when in neutral (and even some in D/R)?

 

vacuum leak, idk where to tell you...

 

It's definitely a vacuum leak. Does this hissing occur in the passenger compartment or the engine compartment?

 

it is very prominent to the right ear of the passenger in the front. I don't know if it's actually behind the firewall or not, but it is ONLY affected by throttle position. I climbed a hill with the a/t selector in '2' and it still did it. It's really hard to capture on my camera's video mode. Otherwise i'd have posted a video already. The mic just can't pick up that frequency range, i guess...

 

does all the vent settings work on the a/c? wonder if a vacuum line broke. thats the only thing i could think of that might be using a vacuum in side the passenger compartment

 

Yes, I second this. The engine vacuum will rise and fall with engine speed and load. The doors and such on the heat/AC system use vacuum to open and close them. Put your head under the glove box and you probably will hear where it's coming from. Replace or repair the leaking vacuum motor or tube.

 

I seem to remember there being an imperfection with the foot vents. Like when you put it in foot-vent only it wouldn't do that, it would do something else. Heat/cold/ac works fine. That's why I thought it was weird though, because I couldn't hear the hissing from under the hood. I put it in reverse up a hill with the handbrake set, went outside the car to the passenger side, then manually operated the throttle... but it never actually hissed from what I could hear on the engine side.

 

it's an exhaust leak... a crack rather than a hole, so the sound is not obviously so, but i know for a fact now what it is... got a new thread about it

 

the way i found my vacuum leak was by checking all the vacuum lines....as there is a vacuum diagram on your hood most likely.

but another way you could do it is to open your hood, start your car and go stant in fron of it near the hood, and try to pinpoint it...and if you need less engine noise while doing so, just have a buddy turn the car off while you look, sometimes it will last longer than the engine noise with the pressure rising to zero.

 

Maybe its your secret turbo

 

well i know it's an exhaust leak b/c i saw seafoam fumes eminating from my ypipe just after the joint... which listening to the sound it makes sense because it sounds like a very faint version of a straight-pipe muffler.

 

also check the back of the IM and make sure those vac lines are connected.

~Alex

 

i've never really had to search for a exhaust leak, because all of mine have been bad enough to basically spot easily.

couldn't you use a technique similar to the one used to cheak for leaks in tires? coat with soap and water and watch for bubbles?? while the exhaust is cold BTW. haha it was worth a shot.

just throwing that out there. lol

 

i'll probably just suck up a small draft of seafoam and look under there and shoot a video of it. that's how i found out i even had a leak. I thought it was a vaccuum leak until i seafoamed. in fact, searching for a vaccuum leak is what led me to select the little vaccuum hose that controls the heat/cold on the manual ac system as my seafoam sucky port. it's small enough to be convenient... and sucks it up very very very fast.

 

just make sure you don't hydrolock your motor

 

love the terminology on the org. haha

still don't see what you're saying though.



lol.....eh?

 

does this seafoam sucky port do any other type of sucking as well?

 

basically if I had not begun searching for an exhaust leak, I never would have looked around at that vaccuum line, and thus would have never bothered seafoaming probably. However, that seafoaming is what eventually led me to find the exhaust leak, due to seafoam fumes escaping from the ypipe itself.

 

sure. lol alright. as long as you're taking care of it, because you lost me

 

Usually with exhaust leaks you get carbon trails. Try looking for those.

~Alex

 

heh, i bet the seafoam got rid of them... oops.

 

ok i found a typo...

 

oh ok, that's where i got lost...wasn't sure what a VACCUUM line was.

broken stud = exhaust leak + over time = carbon deposits (such as just below the SAN) :




don't mind the rest of the dirt there.