I am new to the forum, just picked up a 96 xj manual and a few days ago it started squealing anytime I let off the gas, in any gear. Push in the clutch or get back on the gas even a little bit and it stops. Any ideas what causes this? Thanks

 

Throw out bearing maybe. If you put a little pressure on the clutch can you make it stop?

 

Vacuum leak at the engine?

 

Yes if I let out the clutch at all it stops

 

brakes???

just kidding. sorry I'm no help on standards

 

Well, which is it?

 

Does it do this at idle as well? If so, it's probably the intake manifold gasket. The back few bolts are known for being under torqued and coming loose. Usually a new gasket fixes it. The defining characteristic is that the noise only happens off pedal. Like driving down the road and lifting off the pedal, at a stoplight, etc. If you're giving any throttle input at all, it won't make the noise. The idea is that when you back off the pedal, it causes the throttle to close, which puts the intake manifold under vacuum since more exhaust is leaving than air entering. The vacuum then causes the whistle noise as it sucks in air through the gap between the manifold and cylinder head.

Now, none of this is taking into account the clutch pedal. What are you doing when pushing the clutch pedal in to cause the noise? Are you sitting still, driving, off/on pedal, etc.? I don't believe it's the throwout bearing, since those have always been more of a rattling sound to my ear. Completely different than the intake noise. When my intake manifold gasket went, I thought it was the serpentine belt at first.

 

Possible rear end gear whine? Mine kinda does what you describe, but I have an auto so its a slightly different scenario because of the clutch. Also I don't care cause I'm waiting for it to blow up so I can put full widths under it lol. My whine sound is kind of a whirring noise when I let off the throttle as I coast or slow down to a stop.

 

It's very unlikely that it would be gear whine. That would be speed dependent and have a much different sound.

 

Probably. I was just offering up suggestions

 

Unfortunately, I don't think it even matters anymore. I doubt the OP is coming back. I hate when new guys ask a question and then forget about the thread when they don't get solution right away. At least we tried.