A couple weeks ago my 04 GTO started knocking pretty badly.
I was shifting quickly trying to get used to my new rip shifter. I clutched in second at around 5800rpm, and missed 3rd gear. My shift light went off and I shut it down. Don't think I bounced the rev limiter but I might have.

I then noticed a loud ticking sound coming from the passenger side of the intake.(i found that out later.) I was on a street so I pulled into a parking lot a half mile up the road. There wasn't any noticeable power loss, and it drove just fine. No warnings or engine light came on. Still, I trailered the car home.

Took the valve covers off and checked all the rockers and rods. Everything okay and nothing bent. When bumping over the crank, the rocker on the exhaust valve on the rear cylinder isn't moving... Lifter or Cam??

Today I took the heads off to check lifters. Pulled the tray, I can pull seven lifters, but the exhaust lifter is stuck. Only 1/8th of an inch is visible. Got pliers on it but still couldn't get it out. It doesn't appear to be at an angle.

Any suggestions or possible causes??? Maybe an oiling issue??
The car has small cam, patriot springs, t/s hardened rods and ls6 intake.

Any input is appreciated.. Thanks

 

I'm gonna guess lifter buddy. I don't think you wiped out a cam lobe...of course how much money would it cost to get a new lifter...or new lifters in general?

 

sorry to hear about this man....if you cannot get the lifter out from above...I think the only recourse is to knock it out from below...which means motor needs to come out. Remove oil pan and camshaft, might be able to get a long bar on it without pulling the crank. Bad thing is if the lifter bore is bitched up the block will need machine work and must come all the way down. Lifter bore can be bored out and re-bushed to save the block.

I can't forsee how one would get stuck, maybe the roller end came apart (needle bearings)? Is the lifter still oriented correctly or is it turned looking at the flats?

BTW I've banged my 04 off the limiter many times...don't know if that was a related incident or cause of the problem. If you had a mechanical over rev situation like you hit 1st instead of 3rd and the clutch was all the way out..then yes.

 

Perhaps one of the lifters shifted in the stock LS1 lifter tray. I've been told the LS2 lifter trays are better than the stock LS1's because they do a better job in preventing unnecessary lifter movement. While you are down there, I'd get some LS2 lifter trays from Thunder Racing....they cost like 30 bucks for a whole engine.

 

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