Determining Bearing Wear

[Arc]

If it was mine I would run it with those rod bearings. New ones will have the exact same wear pattern after a few miles. Gasket maker used from a tube is hard to lay down in a good thin pattern and should be used in a caulk gun. Usually that kind of mistake is by a young guy just starting to learn how to use Rtv. I know I sure did put it on thick years ago and I also found it gumming up every hole in the engine.

 

[Chris142]

Looks like it was assembled dirty to me, someone had to pan off. Went to unch and did not clean the dirt off when they got back.

https://www.mahle-aftermarket.com/m...b-2-1114-engine-bearing-failures-brochure.pdf

 

[Trav]

If you can hang a fingernail the on the crank it definitely needs work but if not it is usually serviceable. You realize the tdi engine is still in the euro van not out where he can just remove the crank and send it off to the regrinder.

 

[crashz]

You've come so far! Thanks for taking us through this journey!

As far as the bearings, I'd like to know the damage, so I'd use plasti-guage to check the clearances, but I'd likely replace the bearings as well. The amount of work to drop the pan was just ridiculous, so knowing the old bearings are in place would eat you alive.

 

[97prizm]

Following on from my troubles with our VW T5 HERE (worth a look if you like blocked oil pick ups from excessive RTV use), I'm currently looking to determine if any serious wear to the engine bearings has occurred.

To confirm, before my strip down, the engine operated perfectly with no abnormal noises. The only reason for the strip down is due to random and intermittent oil pressure lights.

The engine has had an undocumented rebuild at some point in the past, and still uses standard size bearings.

View attachment 313154

The crank is perfectly smooth with no scratches that can be felt with a nail or anything untoward.

View attachment 313155

The lower cap bearing seems to have lost it's initial coating in places, but again, is totally smooth with nothing I can feel with my finger nail.

View attachment 313156

And exactly the same for the upper bearing. Slight coating loss, some scratches but nothing I can feel with a finger nail.

View attachment 313157

How do I determine if these need to be replaced? I've done some googling and haven't come up with much.

If there's no scratches, making, or bearing wear, I'm wondering if maybe the oil pressure sensor is bad?

 

[ripcord]

If there's no scratches, making, or bearing wear, I'm wondering if maybe the oil pressure sensor is bad?

Probably not. The oil pickup was mostly plugged with RVT from the last guy who used way too much when putting the oil pan back on.

 

[Exhaustgases]

Sorry I just can't resist. In that first picture there's not enough finger nail to catch on anything.

I've seen videos of the factorys over doing the RTV, as well as the many praised experts on youtube.

 

[CarbonToast]

Im going to say that bearing is just fine and looks new.

For comparison. Here is a picture of bearings from a 106k mile BMW M5 v10. Bit more worn...

 

[ripcord]

Im going to say that bearing is just fine and looks new.

For comparison. Here is a picture of bearings from a 106k mile BMW M5 v10. Bit more worn...
View attachment 313225

They must not have used the special 10w-90 oil in it, lol.

I was in an O'Riellys and a guy came in and asked if they had any 10w-60 oil that it calls for in the owners manual of the Beamer he just bought. The guy behind the counter had no idea oil came in that weight, either. I just bit my tongue and kept my mouth shut. Poor guy.

 

[Bailes1992]

Appreciate all the advice guys. Those M5 bearings really put the situation into context.

I think I'll stick with my original plan. I have Plastiguage being delivered tomorrow, I'll check the clearances and report back here for those interested. If the clearances are acceptable then I'll just resemble with new rod bolts.

The oil squirter was £50, not particularly pleased about that and I'm still unsure if it can be installed with the crank in situ. Wish me luck!

 

[Cujet]

Just an FYI, the reuse of a bearing carries a significantly higher risk of spinning. The bearing is held in place by being crushed a little. There are anti rotation tabs, but they do not carry the load.

It is the loss of crush fit that is the issue. A new bearing crushes and is tight. A used bearing is already crushed.

 

[Bailes1992]

Update in the project thread for those interested. Looks like I've just got away with it. Factory spec is 0.022-0.042mm, It's measuring smaller than 0.050 and bigger than 0.038mm

 

[Exhaustgases]

Update in the project thread for those interested. Looks like I've just got away with it. Factory spec is 0.022-0.042mm, It's measuring smaller than 0.050 and bigger than 0.038mm

Yeah dimensionally fine. What about embedment, and the cause of the scratching?

 

[Bailes1992]

Yeah dimensionally fine. What about embedment, and the cause of the scratching?

Low oil pressure which is why I'm here in the first place.

I can't feel any of the wear or scratches with a nail. Everything is perfectly smooth.

 

[Exhaustgases]

Let a machinist feel it.