WTF is This Noise?!
 

When I let off the throttle there is a crackling/popping noise that comes from the exhaust of my 1988 944 NA. It does not sound like a backfire or anything like that. It usually happens after I accelerate and then let off the throttle to slow down a bit. I think it sounds pretty cool and I was just wondering what it was. Our lawn tractor does this too if you cut the throttle from the bunny rabbit sign down to the turtle sign quickly.

OK, that's funny to me! :)

Vtec

The noise is from unburnt fuel in the hot exhaust flaring off...

Some cars do it, some cars don't. Some should, some shouldn't.

Most properly tuned/timed 944s won't

most likely the car's running too rich.

it's actually called an afterfire if it happens in the exhaust. backfires happen in the intake system and are VERY bad.

"From the bunny to the turtle" haha i love it.

Glad I could make you guys laugh :)

I do suspect that my car is running rich. There is noticeable, but not strong, smell of gasoline in the exhaust fumes.

Thanks for the explanation!

Sorry to bump my old thread, but I have a new noise now. It's sort of a screeching grinding noise. It doesn't sound like a belt. The timing belt is intact. It can be heard when I start the car. The car dies shortly after each start (another problem I'm working on), but I'm mostly worried about the noise.

http://i135.photobucket.com/albums/q...-22-30_182.jpg

Sorry for the quality. It was taken with my cellphone.

I've driven the same tractor!

That is all I have to contribute to this thread.....

http://forums.pelicanparts.com/suppo...eys/hiding.gif

Take care!

Probably the alt. belt too loose.

Would a belt make a grinding noise? I think it might be the starter dying because it seems to come from the rear of the engine and only happens when I start the car. I've only heard it while inside the car, so I'll see if I can someone to start it while I listen.