Hi guys,

I need some help here. I have a '96 SS with 10K miles on it. The other day I started it up and headed down the street and when I let my foot off the gas I got this big POP!! I dont think it is a back fire because it would happen when I was on the gas. Any ideas?

 

Whereabouts did the sound come from? It might be that you have a busted transmission mount if it came from the console, and sounded like a "thump."

 

It comes from the exhaust, sounds just like a backfire!

 

That's no big deal, every f-body does that. Totally normal. Certain exhausts can make it worse though.

 

try checking your coil wire and plug wires and plugs.If valves are too tight it can pop too.

 

Thanks Guys, I just took it out and heated it up a little and knoticed that it is much less significant after the motor heats up. I was thinking maybe I have a vaccum hose off somewhere?

 

that's what the AIR pump is for.....it helps the cats heat up. once they're heated up there is a significantly less amount of popping. you should hear it with my cutout! sounds like fireworks are going off under the car when im doing 80 / let my foot off the gas and when i get back on it, BOOM!!!!!!!! lmao

 

I've got the same kind of deal. It's only happened a few times, but if I just start it up and get going, sometimes on the 1-2 shift it'll kind of clunk. I can really only hear it if the window's down. It's only done it once or twice in the few times it has happened, then it goes away. So I figure it's not that big of a deal. *shrug*

 

With my cut-out, when my engine is cold, the backfire sounds like gunshots and it backfires less when it warms up with no loud pops. Its perfectly normal, even when I cap mine, my "quiet deep sounding" muffler backfires. I've heard many new SS' with stock exhaust still backfire as well, but if you are worried, i'd check your coils and wires, but I don't think that's the problem.

 

My car backfires loudly when cold, a few times when warm.

Do you guys know what causes backfire. Is it fuel thats being burnt up or something like that?

 

A backfire is unburned fuel mixture being ignited in the exhaust system.

 

And certain exhausts can make it worse?