Hissing noise from truck?

Question

I have a 1991 Ford Ranger. Recently it has been making a low, soft hissing noise while going down the road, kind of a quiet pssssssssst. I'm taking it to a garage tomorrow to get a couple other issues resolved (idler pulley, pipe connecting carburetor to muffler is rusted...hey! it's an old truck, but I'm a poor college student!)

Any help or advice would be greatly appreciated. I'm not sure this is associated with the brakes or what. :)

Answer 1

1.may be radiator leak...got coolant in it?

2 vacuum leak..lots of hoses and lines under hood

3 exhaust leak

4..u ask abt brakes...are the acting up? maybe master cylinder/power brake booster..[ runs on vacuum]

5 . a1991 has no carb...its fuel injected...know that so u don't sound like a dope at the repair shop...lol

Answer 2

It would be really hard to say.  It could be a tire, but then you'd know it by being flat.  Or like some others have said, could be an exhaust leak, or radiator leak, but then there you'd notice a smell of antifreeze as your driving.  Or it may even be something dragging down the road, as your driving.

Answer 3

I would agree with deltafox...

Answer 4

AHHH JAYSUS its a snake!!!!!!!

Answer 5

It is not normal but I have heard the serpentine belt make this hissing noise so it might be when you get that idler puller fixed it will go away..  Normally they squeel but my own personal car made this hissing niose it almost sounded like someone blowing really hard through a straw...  Mine is also a ford...

However it could also be a vaccuum leak...

Answer 6

This sounds like a leak at the exhaust manifold, probably an exhaust gasket

Answer 7

leaking radiator... sounds like steam escaping...... or your a/c freon...  see if you can locate the pssst sound.. would help determine problem..

Answer 8

vacuum line or its hot either one will cause a hiss juts tell them to fix it