Hi Guys,

1st post, in need of advice.

I have the knock of doom. The one everyone really never solves. The one that when you look it up on youtube, they say "thats normal, or I drive it like that, or I swapped the engine, or I threw all the parts at it, and it stopped"...

Before we go into all my findings, Im pretty sure its the number 2 wrist pin.

Main questions are: 1. Is this typical. 2. Does it mean more are going to happen. 3. Can I just change the one, and its gonna run another 200k.

Dont talk me into a 606 swap, Ill fckn do it, I swear!

Background. Car had been taken car of mechanically pretty well for as long as I can tell. I take care of it the same or better.

What I am not good at doing, is driving this thing softly. I was into it pretty good, and am most times, when I heard a "different" noise appear. Only drove it with the noise a few miles at as low as I could/side street rpms. Im not beating on it, but its driven at 36-4100 rpms for 20-50 mils at a time. I dont rev the piss out of it getting the the highway. Even though it shifts at 5100 if I let it!

Pre chambers are perfect. Injectors pop with in spec +/- 1850psi. Installed new pre chamber crushes and injector washers today.

Compression is: 1 320. 2 320. 3 360. 4 340. 5 340. appox 25o,xxx miles.

Cyl #2 has visible scoring on 1 part of the wall. Very minor, but its there. All other cylinder are clean, and crosshatched. Tops of pistons are clean/no pitting/heat damaged (this surprises me)

No bearing material in the pan.

Dropped the upper oil pan, and all rods are tight/not rocking.

Oil pressure is 20-25 at idle, 45-65 driving.

Noise can be audibly heard with a screwdriver to the ear at cylinder 2. Obviously it echo's throughout the engine, but it is definitely the loudest at cyl 2.


So... Back to my questions above. My concern is if I only change cyl 2, is it eventually going to happen to other cylinders. Meaning is this the beginning, and if I dont do em all, im doing it wrong.

Im happy its cyl 2, cause it means I dont have to pull the engine.


Personally, I would rather take the time to do the OM606 swap, than do a fresh/full rebuild on this engine.

If its just pull the head, and 1 piston/bearing assembly, Im ok with that (also timing chains).

Happy to hear your suggestions.

Thanks.

Tom.