bearing failure on AMG block?

[Busted]

I had a truck come in with what the owner thought was a spun bearing in a low mileage AMG block. I'm guessing that the stacked chips are the reason it didn't go to the dealer for warranty, but anyway . . .

The second main bearing from front (1st of the three middles) is shown below. It hadn't spun, but obviously failed badly. I'm looking for some more experienced opinion on why it would fail like that so I can make recommendations as to possible upgrades or driving habits.

Also, I'm guessing it's not a good idea just to swap in a good crank and new bearings, as there were metal flakes in the oil pan . . .

http://i20.photobucket.com/albums/b222/Byronm/DSCN1382.jpg

Opinions?

[More Power]

Perhaps either the bearing clearance wasn't right, an oil passage in the crank/block wasn't right or the owner ran it low on oil....

In general, a low/no oil pressure episode causes a main bearing failure toward the front of the engine (usually #1 main bearing) and a turbo failure because they are the last in line to get oil. I hear of this occasionally when an owner reports an engine oil cooler line failure.

Jim

[Busted]

that's good to know, I haven't pulled the #1 cap yet so I'll check it as well. Turbo is in good shape.

No evidence of oil leaks on the truck and cooler lines are original--are you thinking that the low pressure he mentioned might have been the cause instead of the result of the bearing failure?

What are the chances that bearing particles are distributed through the rest of the engine and may cause further damage if I just replaced the crank and bearings?

[Robyn]

With this type of catastrophic failure the engine needs to come all the way down and be totally cleaned and the cooler cleaned as well.

The oil goes through the cooler before it enters the filter so any crap can be sent to the cooler.

This is never a pleasant task but necessary to be sure the thing will live.

Be sure the oil squirt tubes are all in the main webs. If one is missing this can create a shortage on that bearing.

Best

Robyn

[Busted]

I was going to ask where the oil squirt tubes are located ;) Now to get the thing yanked and see what else is going on . . .

[john8662]

Probably an assembly problem initially.

I pulled down a 2000 or so model goodwrench 6.5 a couple weeks ago and it had six spun rod bearings, no spun mains. The only two good rod bearings were for cylinders 1 & 2 on that journal. Odd, crank is TOAST, but block is good, throwing it in the corner for another day.

I second the opinion of pulling it completly apart if metal is missing off bearings.

J

[6.5 Detroit Diesel]

Still waiting to see the pictures of that truck. Sounds like it is coming right out, eh?