On my 93. When you're idling and you rev the engine to about 3 grand and let up and when it gets back down to around 1500 it will go POP kinda loud. Sometimes it will do it if you just rev it around 2500 rpm. I have absolutely no idea what it is, It never does it in gear or while driving. Only while you're setting still. I think it'* something in the tranny, It shifts perfectly with absolutely no slipping or anything. But the otherday I was trying to get it to do it and it did and when it done it it rolled back a little bit then caught like it had released itself from park for a split second. I dont know if that was related or not. But anyway I would like to get this one figured out. :(

This is totally normal. Please don't free reving the motor unless you have a good reason.

Could you please explain to me what it is then so I will not worry about it. I've never had a vehicle that does this.

Get up from a nap. Walk 3 feet..then run at 50mph for 30 feet.. then stop quick. That'* what you are doing to your motor.

Essentially it'* a backpressure/backing off noise that is the motor changing from high rev to slow down mode.

No whatever it is is inside the tranny around the bellhousing area. I'm going to crawl under it this evening and check the torque converter bolts, Flywheel for damage or looseness. But I dont think that'* the problem either. I just figured someone may have had this problem before.

Billboost is correct,the pop you hear in in the cat. converter I accidently did that one day when I got out my foot slipped and hit the gas and let off and it popped.

Well...cat or not.. I'm unsure.. it'* exhaust gas related basically. It'* the sudden release and reversal from rev to coming back down. Not all vehicles do it..usually it'* the faster reving engines.

Did yours jar the whole engine compartment when it done it? Mine sounds like taking a hammer and smacking it against the top of the trans.

Well I went out and looked at it this evening, And there'* no doubt it'* coming from the trans.
When it popped it rolled a little again like it'* coming out of park for a split second. It doesn't roll every time it pops,and it doesn't pop every time. just every once in a while.And when I put it in neutral and rev it a little the speedometer goes up then it pops lightly but it does it real loud in park. The speedo thing I never noticed before, But there'* no doubt it'* all related. It'* like somethings catching inside the tranny when it comes back down from a slight rev.