Thread: 300 TDI engine bearing inspection

I'd do big ends definitely but while its out may as well do mains, i would reuse the bolts/nuts.
There has been a discussion on this previously.

I think you can use the bolts again, it is only torque to yield bolts that can't be reused.

At 310 k km you will be replacing all the bearing shells you can access with the block wherever you have it. You could use plastigauge to measure the gaps if you need convincing. The crank journals could also be a bit out of round and if so would benefit from machining.

Someone with experience with these engines will be able to tell you what generally needs to be done, you might get away with changing the big end bearings only. The cylinders will also have to be looked at although I think these engines are not too hard on the bores with cross hatchings still present when dismantled so new stand size rings maybe all that is required in this area.

If it's gotten real hot replacing them is pointless,the block needs to be checked for distortion before you do anything or your wasting your time. Pat

Thanks for the replies,
I think PAT303 makes a very good point there.
It turns over nicely by hand, but I guess that doesn't really count for much.

Run a straight edge across the block,any day light she's toast. Pat

So engine is out and fully stripped.
We put a steel ruler and an old engineers square across the face of the block in all directions but the smallest feeler gauge I had was a 0.2mm so this proves nothing.


Bearings and journals all look good for 310 000 K's.


Bores all have something funny going on. Shiny marks running up the bores like they have been polished. Crosshatch is still present outside the polished area.


Piston skirts all have marks on them, some worse than others.


It's off to the machine shop tomorrow to get an experts opinion.


Took a few photos to show we had done something today.

That is a 310k km engine ok, seen photos of worse bearing wear in less km.

As per the photos the bearings are starting to show the cooper base, the crank looks ok. New bearings for sure, I'd hazard a guess that you might be able to get away without machining the crank. But as you say the machinist will tell.

The bores will have to be done if you want longevity and with that will go oversize pistons and rings, the costs will start to mount now as the injection pump and injectors might need a service, the gearbox and transfer case might also need a bit of love.