Yeah I was driving down a back road and got on the throttle and the engine hestitated a little bit but still pulled hard. I felt the clutch pedal get a little loose and vibrate more than usual. I pulled into a parking lot and heard the engine knocking a little bit but real noticeable if you rev the engine a little bit (1000-1500). It knocks real loud and it sounds like it's coming from under the UIM or on the turbo side. The car does not pull hard as it usually does and it feels laggy. It will almost die every time I rev it to 1500 and then idle back to normal. It doesn't have trouble idling at all. Any ideas? I'm going to get a compression check in a few. Sorry if it's choppy kind of worried...

 

sounds like a clutch issue. Could be a bent prong on the pressure plate or maybe damaged the clutch fork. Maybe the clutch wasn't torqued down to spec and some bolts worked loose. I'd reccomend seperating the engine and tranny and having a look.

 

+1^^^make sure to check your map sensor too just in case it popped off...hopefully it just a clutch issue if not sorry to hear man...

 

It's been cooling off and now it has problems starting. Hesitates on throttle too. I think maybe a bearing issue.

 

^^ Yeah maybe not.

It's been starting fine. The front main pulley does not vibrate or move any out of the normal. The flywheel is still tight and in perfect alignment while the engine is on. I'm going to pull the tranny off tomorrow and check on the rear side of the engine. I still have no idea what the problem is. No cooling issues, idles fine, starts decently (two times it hesitated), boosts still and I'll tell the compression status tomorrow. It feels like it could be the clutch messing up but it seems kind of strange as it only has about 5k miles on it. (Spec stage 3) It has a lightweight flywheel also.

 

I wouldnt imagine a clutch issue causing the car to fall on its face. Possible slip but you would know the difference. What is your Vac reading at around 900 rpm? Pulling the tranny is a lot of work to just take a guess at. I would do the compression test and then go from there.

 

is the loud knocking and cutout only when the car is under load? ie while moving?
can you rev pretty freely in neutral?

 

Vacuum reads around 450mmHg or normal for this gauge. It's always been ~that. It revs fine and it seems to knock under load or when I let off the gas.

 

or ~16lbs @ 750rpms

 

http://www.youtube.com/v/k4quhEJCwy8

 

Anytime you hear a rotary knock like a rod in a piston engine, you know it's a bearing issue. This usually also effects compression in at least one chamber pretty severely, as the extra "play" allows the rotor to contact the adjoining surfaces and chews up seals and clearances.

Take a look at your oil for microscopic particles. If it were me I would go ahead and start pulling it.

 

Compression Test Results:
Cold engine compression
95 front, 95 rear

Seems kind of odd if the engine lost a bearing to have such good compression...

 

Well, if you've removed belts to eliminate belt driven accessories, and it is RPM dependent, the only things left are engine internal, clutch rotating assembly, or trans. And you can eliminate the trans by holding the clutch pedal in while revving.