98redstang

i have the same damn thing. I cant figure ou where its coming from and its not an exahust leak cause it wouldnt be a constant hissing it would be like a pulse of hisses. I have the exact same symptoms as you though if i rev it a little it gets louder but after the car warms up it slowly goes away but it happens everytime i start it. Tell me if you find out the solution cause its pissing me off.

E714FEVER

Thats a positive crack case vent tube. You have one on each side of the motor on the valve cover. It sounds like you have blow by. I dont think its all that serious mines been doing it for over a year and I havent had any problems because of it.

Chubstang

I would guess you have a vacuum leak at the brake booster. Inspect all of the rubber lines for cracking/dry rot.

livefast1

brakes are hydraulically assisted from the power steering

blownstangboosti

this could be the problem I curently have it after i drive aroung the hose comes off the egr sensor and makes a kind of flutter when you accelerate. you should check it out its right where your refering the noise is coming from.

Modular_Madness96

its that rubber hose that connects the tube to the intake.they get old and need to be replaced i actually had a peice of i think heater hose that i cut to fit when mine did that.what youre hearing is the intake sucking air from that tube and the reason theres oil there is because the newer cars all run a closed loop setup for the pcv's.replace that rubber hose and it should cure it

cassimus

funny i found it but it doesnt make any sense it was the spark plug boot on the driver side 3rd one back from the front i can move it more vertical under the fuel rail and it almost dissappears instantly and it comes back when i move the boot more towards the valve cover i dont know anymore im stumped