Hissing Noise At Plentum

[BlackendZ34]

The only way I can describe it is imagine the typical make a snake sound

 

HISSSSSSSSSS and just take off the "hi" part

 

so it sounds like a SSSSSSSSSSS at the plentum and just above it.

 

Sometime its not there and time times it is. Im guessing its air but Whats right below that or what do you think the issue is with the car?

 

Thanks

 

BLKZ34

[Guest Anonymous]

Plenum gasket leak.

[BlackendZ34]

Would All i have to do is take off top of enigne and replace gasket?

 

If thats it I think I could do that myself?

[Intimidatorz34]

Well when you say at the plenum and just above it......do you mean above it as in above where the plenum meets the intake or above as in towards the back of the motor near the firewall.

 

If its toward the back check the hoses to make sure they have not disconnected from anywhere. I had a vacuum line come lose from the map sensor and it hissed.

[OldsmoBeast]

yeah....definitely vacuum.....could be gasket, but also very well could be a broken line anywhere...those things go brittle

[BlackendZ34]

Ok so monday when i take the part off thats says 3.4 Twin DOHC and the ruff cast metal part thats further back , ill see hoses in back and a gasket in front?

 

then i should check for hoses that might of slipeed off? and if there is none replace gasket?

 

Can I crank the engine w/ the top off?

 

blk

[Stevo]

Holy Jeez I just noticed the same thing today.

 

I have a hissing air noise coming from the back of the plenum as well.

 

I was checking all the connections when I burnt the back of my hand. :x

[Guest Anonymous]

Ok so monday when i take the part off thats says 3.4 Twin DOHC and the ruff cast metal part thats further back , ill see hoses in back and a gasket in front?

 

then i should check for hoses that might of slipeed off? and if there is none replace gasket?

 

Can I crank the engine w/ the top off?

 

blk

 

Try to check the hoses before pulling the plenum. If you can't, pull the plenum, check the hoses and replace the plenum gasket. Don't crank the motor with the plenum off. You'll just hear the lower intake sucking air anyway.

[Stevo]

Well...

 

I located 'a' hose but I am not sure where the hell it goes.

 

Like I said. It must have just popped off the other day.

 

It's obvious a hose for suction into somewhere because placing your thumb on it does not change the engine's idle and I can't feel anything coming from it.

 

However. I do suspect the plenum will have to come off to reconnect it. FFS.

[LarryMartin830]

my 3.1 in my cavalier was doing that i changed the gaskets and it stoped