NEED HELP!! odd vacuum leak

[slick88gt]

Okay, I've got a 97 with a 3.1 in it. I suspect the lower intake gasket is bad because my cooling system never retains any pressure but I can't really see any coolant leaking anywhere. I do smell it tho. Anyway I am getting this odd vacuum leak. When I first start the car in the morning when its cold out, it idles really high at like 2k. When I drive it the brake pedal is really hard and every stop it idles at about 1500 to 2000. Symptoms of a vaccum leak right. Well as soon as the car reaches operating temperature I shut it off and immediately restart it and it idles fine at about 600-700 and the brake pedal feels normal as if the vacuum leak went away. I have tested this in many ways for the past few days (I just bought it a week ago), and every time as soon as it gets warm I can just shut it off and restart it and it runs normal. At first I thought the lower intake gasket was causing a vacuum leak but if this was the case then simply shutting the car off and restarting it at operating temperature would not fix it. Any ideas? I'm stumped.....

[Forkliftguy]

This may sound "crazy", but a fairly easy way to detect vacuum leaks is by using a hose about 2 feet long and holding one end to your ear and running the other end along any areas yhat could leak. Like along the length of old hoses especially at bends and where they make their connections to fittings, tees, etc. You can also check around gaskets, etc. The only problem I see with this method is the fact that you have to listen carefully sometimes, especially on smaller engines like 4 cyls. Another good item if you have one is a stethascope with the listening device removed (the round piece at the end of the hose).


Marc

[slick88gt]

Yeah believe it or not but I've actually already tried that lol. Another method is to spray carb cleaner on vacuum lines etc. and if there is a leak it will suck the carb cleaner in and the engine will bog down for a second. I tried both with no luck. The fact that every time the engine gets warm and I can just restart it and it goes away tells me that its some kind of sensor. The only thing I can think of is maybe the egr valve is getting stuck open and causing a vaccum leak, but when the car is warm the compueter actuates it causing it to go away. Any comments on this theory??

[slick88gt]

Nobody has any ideas? Come on guys, I can't afford to take it to a shop, any advice would be very helpful. Thanks.

[Knifeblade]

K, three quick thoughts, though you certainly have weird symtoms.

EGR, IAC, TPS, MAF sensors.

surf www.autozone.com repair and diagnose section

Bleed the brakes.