So, as of two nights ago my car's been making some strange noise.


It's NOT pinging, otherwise I'd be crying.

When I start my car, it makes this hellish knocking noise like there's a pebble in my exhaust. The noise stops after a few seconds, but whenever I stop giving the car gas (I.E. on shifts, stops, etc.) it makes the noise for a second. Anyone know what's going on?

It sounds like the noise is coming from the rear of my car, should I be worried about some problem in the driveshaft or something?

 

sounds like something might be loose. (duh) is it a turbo??had a similar sound and it was my wastegate accuator flappy thingy

 

Not turbo, it's an 89 GTU.

It sounds solid while the car revs, but when the revs start to fall it knocks for a second.

 

Bumpittybumpbump.

 

does it make it when you first get on the throtle too? it could be the exhaust hangers are loose and the exhaust is banging on something. happend to my dads car

 

Nope, it only does it on startup and when I stop giving the car gas.

 

are your cats gone? could be some little backfires?

 

backfire.

 

Really, just a backfire?

My cat is still in, looks to be one of those ghetto universal ones though so it's internals are probably shredded by now. Could that be the reason that it wasn't making that noise before a couple days ago? (I mean, could the internals have just recently been thrashed due to a couple redlines, and be backfiring because the cat is essentially hollow?)


If so then that's good news, I'm planning on replacing it with the
Racing Beat Street Header/Bönez Cat System

for $450 in a month or so.

 

You'll get backfiring with that setup too.

 

When i bought my car i kept hearing a rattling noise and i couldnt figure it out. Turns out the insides of one of my cats had broken into pieces and was rattling around inside it. Hope u figure it out

 

Backfiring is fine with me, I was just afraid that something was hopelessly F***** up.

 

UPDATE:

My cat DOES have an air pump leading into it

Now I don't know what the hell is going on. The cat. looks pretty solid, not cheap.


Then knocking/rattling noise vanishes after the car's been warmed up.

Any ideas?

 

Anyone?

 

Whats the Golden Marmoset population like out there in San Jose? Little bastards will get into anything......