I was driving around for rougly an hour and a half with no problems, within that time period I turned off the car a few times and went places. Everything was fine until it started and made a very weird noise from the engine. I popped the hood and checked it out, it seems to be coming from the top left of the engine. I can hear my right cat vibrating from it as well. I drove home, it shifted fine but at low speeds I can hear something clunking around. I got home and let it rest for a few minutes and started it back up. It idled for a while, all my gauges are fine, volts good oil good then it dies out. Start it again and the check engine light is on. The best way to describe the sound is a knocking.

 

Go get the code checked out. Sounds like a cat could be clogged but im not forshure.

 

I understand you said you weren't sure but would a clogged cat make a severe knocking noise? How about the check engine light? Also, I meant to say that the noise is coming from the top RIGHT part of the engine, near the throttle. Anybody else have any advice? I'm taking it to a shop Saturday.

 

it could almost be anything...a slight clunkin sorta sound could be caused by the cat bein clogged but it should be alittle more high pitched...the code will give u the answer...i hope it aint anything bad man

 

i doubt that it has ANYTHING to do with ur cat. take it from an old g... thats just wishful thinking... sounds like serious interna l engine problems... check the code, then get back to us....

 

Bad news! Pulled codes, one of the heads was slightly leaking oil over time but not enough to notice. Eventually the spark plug blew and the engine might have sucked up a small porcelain piece.. There's a possibility it has blown out through the exhaust, we didn't find any pieces in the engine so far. They're gonna strip it down, replace the boots, plugs, and see how she runs. If they do a compression test and everything seems fine I'm gonna have them put in a new header gasket, if somethings off then I'm pretty much ****ed. I'm not interested in buying a new engine.

 

I'm guessing the knocking noise was the cylinder firing.

 

I should be getting an update tomorrow.

 

The sound could have been the compression leaking around the "blown" plug. Hopefully the porcelain didn't damage the piston.

 

Dang my 03 started this knocking noise yesterday and dont know whats wrong with it...it goes to the shop in the morning. It has new plugs in it so i hope it isnt anything like what happened to yours....but that sounds about right. but dang mine is making noise from right around the TB. But mine has a tune would the check engine lite come on at all if there is a tune in it? mine hasnt came one so i dont know...im sorry about your car that sucks!