on top of my 3.1 having a loud hiss and the rough idle with jumping rpms, it is now very shaky literally

when i turn it on it has a rougher idle than before and it continues even while driving. it has even stall out a couple of times

as time goes on things keep getting worse and worse. it feels like my car is about to die!

since i know very little about engines or anything under the hood i am taking it to a garage tomorrow. what should i tell the mechanics to look for in particular? i wanna have them hook it up to a computer. if there is anything wrong which i know there is will it show up on the computer?

 

vaccum leaks

 

MD nailed it. Totally vacuum. Listen to the hiss..track the noise down by ear...look for disconnected hoses first...or hoses with big cracks in them. Check all the vacuum hoses..they're all flat black, usually made out of rubber I think. Replace the leaking hose. You'll know if it's the hose causing the roughness cause if it's cracked, wrap your hand over the cracked area...if it's disconnected, plug it back in where it should be or stick your finger at the end of it to seal it and your idle should jump right up. The best way I've found of tracing vacuum lines, most of them anyways, is to start at the back of the plenum. Examine all the hoses coming out of it, and the hoses connecting to those..trace them all down and that should be basically every vacuum line in the car...have fun!