Rattle, hopefully not of the death variety

[Andini]

I just obtained a 1990 YJ with around 212,000 on what I think is the original 2.5. It pulls strong, and under load doesn't make any rattles that I think are uncommon (although the water pump is starting to make a "replace me" noise) My question comes about when I unload the motor i.e. disengage the clutch. Sometimes (not always) I get a big rattle, which I can't locate, it's either in the rear end, or in the motor. I can't locate it because it generally happens at low speed, and tends to be accompanied by a motor stumble. Any ideas what might be making this happen.

Gears, tires etc. are all stock

Thanks for the help

[Jeffy]

I'd check the engine mounts to see if they are still intact.