Hissing Noise

[brenden84]

hey guys. this morning i got in my bronco started it up and it stalled right away. pretty normal but once i got it going again i noticed a hissing noise, sounds like air escaping through a hole like u would hear with a punctured tire except louder. its definatly in the engine somewhere and im guessing one of the belts. i think the engine stalled becuase there was too much strain on the engine, not being warm and all, like when u try to accelerate quickly with a cold engine. Thats why im thinking it might be a belt or something thats really tight, however, this happened overnight, nothing unusual was going on and then the next day the noise. i dunno.

any ideas?

thanks

brenden

 

[fbrown3]

I would check for a loose or dis-connected vacuum line, some times the power booster will start leaking and cause it. Thats what I found with an F350 I had a few years back. Good Luck.

 

[brenden84]

i did find two lines up near the fire wall that were disconnected. they were all attatched to a piece that held three vacum lines of some sort. i reconnected them and the noise still persiststs. it lasts still for about half a second after i cut the engine. im gonna take it in soon and see what they tell me. any more ideas would be helpful. thanks guys, peace

brenden

 

[Desert Donk]

A thought coming from me, one of the greenest mechanics on earth is a bit laughable. However, from your description it reminded me of a problem I had once. It was a loose exhaust manifold. Just a thought so take it with a tablespoon of salt.

 

[sweepersrgr8]

Do you have A/C? If it is happening still, after you turn the engine off, I would suspect a leaking compressor.

Also check the lines going to your vaccume canister, it could be leaking as well.

 

[brenden84]

no my a/c is all disconnected. wheres the vacum canister?

 

[james50cal]

Just a thought you might want to check your fan clutch. I doubt that is what it is but check to see if it is locked up. It will cuase the fan to spin all hella fast and you will get that rushing air noise.

 

[sweepersrgr8]

The vaccume canister should be on the passengers side inner fender. Most of the ones I have seen look like a big stew can with 2 small hoses going to it. Although I have seen a few that look like a ball, about the size of a grapefruit.

Pick up a vaccume gauge( they are faily cheap), and test all vaccume operated equipment, brake booster, pressure regulators, reservoirs, etc.

Check your spark plugs, make sure they all are tight, it could be a compression leak also. Look in the radiator for air bubbles(take the cap off, and let the engine warm up first).

Check your fuel pressure, you could have a failing check valve allowing fuel to drain back through the pump.

Sounds more like a vaccume leak, but just a few other items to check. Carbed of efi the Bronc should start, and run fine...If all is well.

 

[Wliebhard]

That vaccum fitting with three prongs simple adds fittings to a vaccum source, so if one is not used or capped, then you will have a leak.

 

[brenden84]

ok cool. of any of the things u listed is there any danger to me or the vehicle likely if i continued to drive it for a week or so?

thanks, i'll check that stuff

brenden