Vacuum leak?

Evan_90SC

Registered User
My buddy has an 89 sc and for about a week now he's been hearing this weird hissing noise coming from under the hood, but it was mostly only noticable when he was driving next to a wall and the noise bounced off of it. At first we thought it might be a problem with the supercharger, but this morning he called me and told me that the noise was much louder and more noticable. He said that he popped the hood and listened and it sounds like the hissing of air being sprayed. He also said that when he started it up it idled really high, then came back down and almost died, but then it idled back up to normal at the last second, and then was good, (despite the hissing noise). In drive he was normally getting 25 to 30 psi, but he said now it's down to about 15. This sounds like a vacuum leak to me. What do you guys think?
 
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A good way to find a vacuum leak is to take a can of carb cleaner and spray it around suspected areas while the car is running, when you find a vacuum leak the engine will smooth out or speed up. Small short blasts or the carb cleaner will do the trick. You can also do the same with a propane torch {Bernzomztic} and a piece of hose it will do the same thing. REMEMBER DO THIS IN A WELL VENTILATED AREA AND HAVE A FIRE EXTINGUISHER HANDY. :eek: You probably wont need it but it is always a good idea.:D
 
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