What exactly do you mean by a knocking sound? Does it vary with engine RPM?

 

It doesn't have any sound of knocking when its idle but when I start getting up to 3-4k rpm I hear it and also when I take my foot off the pedal I hear it for a couple seconds. Its also constant when I keep the rpm at around 3k...the sound is constant and repeating. Not just a single sound like a piston slap. I've also checked the heat shield and its secure.

 

Something in your turbo? 3Kish, when you hit positive pressure, your turbines might be doin' some monkey business.

Is your OEM uppipe replaced? Catalyst in the turbo? :eek3:

 

Stuck valve? I've dealt with a couple of these lately and it was kind of a banging noise that would go in and out depending on RPM..



Get under the hood and rev it, if the sound is coming from the passenger side head I'd bet it's a stuck valve.




You might also want to check your oil for metal.. just in case.

 

I just put it up on ramps and i heard it start to knock at lower rpm's when the car was under load. I don't hear anything when i slowly accelerate only when its under load (or accelerate more quickly). I tried to put my ear as close to where i thought its loudest and it sounds like its coming from around the 3rd cylinder. If the catalyst in the turbo was bouncing around wouldn't the clatter be kinda random? This sounds more to me like a metal knocking sound that's continuous but always the same as in its not random knocks...it follows the rpms. I will try checking the oil and try to inspect the turbo/uppipe this weekend. If I have to rebuild the engine..what would be the best route to take? Are we looking at like a $3k job? Thanks guys...

 

If it's coming from the area of a cylinder, I'd start to wonder if the rod was ok. A bad turbo or valve is more of a high-pitched noise of tapping/scraping. Knocking usually points to the bottom end or cylinder parts.

 

So I ended up checking oil and found no flakes...then took the Turbo off and there's lots of shaft play..I'm hoping that's it..I mean it has to make noise when it gets spinning right? The up pipe was intact so none of that got sucked in but the Turbo itself must make noise when it gets spinning rapidly...?

 

Did it end up being the turbo?