Thread: Rotating assembly repair without removing engine?

I just purchased a 2002 GTP coupe with 84K. The car is in mint condition except for the motor. At about 4000rpm the motor has a knock somewhere in the rotating assembly. It also appears to have a problem with the LIM gaskets; water in the oil. I plan on replacing the LIM and supercharger gaskets soon. Scanned the PCM - no DTCs

Question:
In the case that the knock is not from a missfire, what kind of rotating assembly repairs can be performed without removing the engine? The knock sounds like a rod bearing or piston slap.

Any comments are greatly appreciated.
...hope I posted this in the correct section

Originally Posted by BillBoost37

It's tough to sneak the flywheel out w/o unbolting the trans from engine. If you want to fix any part of the rotating assembly and don't take it to a machine shop (in which case a used motor is usually cheaper) then you will have the 200 mile motor. In about 200 miles it'll likely fail again.

werd.

All

Thanks for the comments.

The reason for the question is that all my tools are up in Pennsylvania and I now live down here in Texas. My garage is all jammed up with crap anyway...didn't want to leave a motor on a stand in my driveway. Our HOA would have a seizure!

I'll start with a compression test. If that's good I'll probably drop the pan and unbolt the caps to see if any bearings are toast. If any journals are bad the motor will be removed.

...or maybe I can fix the cranksaft with my Dremel tool...just kidding.

Any other suggestions for troubleshooting?

Thanks in advance,
Love this forum!

I isolated mine by raising the rpm untill I heard the knock and then used a test light connected to ground to short each wire at the coil untill the noise quit. I used a small piece of vacum hose between the wire and coil tower so as not to damage the wires. This may help you isolate which cylinder. Most of the time I find its the rod bearing and fyi do not reuse the bolts.

Sorry for replying to an old post but I just wanted to give an update and ask a couple questions.

I unbolted the down-pipe, removed the upper mounts, jacked the engine up, removed the lower mount bracket and dropped the oil pan. The mount bolts are hellacious and it was hell getting the oil pan off this car due to the interfering pickup tube. I used a 15mm pivoting ratchet wrench to remove the mount bolts.

Anyway, I removed the rod caps and someone has been in this engine - big time. Three rod journals are trashed and it has mixed bearings; std, 0.010 etc. I made the decision to rebuild the short block.

Question: What should I replace on the transmission while I have this thing apart?
Question: I would like to eliminate the balance shaft. Should I just mig weld the rear oil galley closed or is there a better/safer way? I was thinking milling a rod down to fit the hole and just spot welding it in.

Thanks in advance for any replies.

"On the trans. Pick up a set of channel plate gaskets. Then go in and replace the 4th hub clutch shaft. Frequently you can pick them up off Ebay for $45ish. Pull the side pan, oil pump, then take the valve body and channel plate together. That way you don't deal with the checkballs or two more gaskets. Zip up the 4th clutches and slide in the new shaft. Reassemble and enjoy knowing you won't lose 4th due to sheared splines."

Thanks you Billboost37
Great info.

I've rebuilt the valve body on the 4L65E's but going any further than that may not be within my realm of expertise. Especially since I'm unfamilliar with the 4T65E. I guess I'll know better when I get in there.

Any experience with removing the balance shaft on the 3800?

Thanks