pcarfan944

For a few months now, only when the engine is warm and after a few miles of driving, I hear a hissing/gasping for air noise when the car is at idle, almolst always at a stop light, in a parking lot, or in my driveway as soon as i'm done driving. It lasts a few seconds and then goes away, I can make it happen again by revving the engine and letting it settle back down to idle, or whenever I come to a stop after driving again. It sounds like it's coming from the frontal area of the engine compartment, but it's hard to say for sure. I just had the 30k major service done (t-belt, water pump, etc etc..) and was hoping it would be corrected by that, but it wasn't. My initial thoughs would be a vaccum leak since it does idle a little rough, and sometimes erratic (more so when warm, idles perfect when cold). Any other ideas?

tcmdocs944

Vacuum.

Check the lines you can see.

You could do the propane test if that fails. (unlit propane torche around lines, engine idle increases...bingo)

pcarfan944

I did check the vaccum lines around the back of the engine compartment (next to the brake lines and fluid) and they appeared ok. Thanks for the tip, I should add the car is a 86 944 non-turbo with 109,000 miles.

Operator

does it sound like my problem at all:
https://rennlist.com/forums/924-931-944-951-968-forum/154925-strange-idle-sound-when-warm-sucking-straw.html
check my mp3s.. similar at all?

tcmdocs944

There is a line under the intake man that goes to the charc. cannister. It is really subjected to alot of heat and hard to get at. Mine went on both ends first with a hiss.....later I started to smell gas (other end going)


Just a thought

pcarfan944

Sounds like we've got the same problem, glad i'm not alone :-D Have you had any progress with yours?

StupEd05

tcmdocs944 - when it went completely does it make your car stall or not start?

Operator

not yet. it just bothers me.. sounds like something bad is going to happen soon but i cant figure out what the heck it is! apparently no one can. vacuum lines sound possible but all of mine are good from what i know. if you find anything new, pos it here i guess.

pcarfan944

Next time I have it in for an oil change I might mention it, but i've been driving it like this since spring with no problems, so unless the car breaks down i'm not going to worry too much about it.

pcarfan944

*knock on wood* Crap, I think I just jynxed myself for my 2 hour drive on Friday