My point being that it would not sink to the bottom and fit the scenario in a way that would make any sense.

My thinking too, but thought maybe some new scientific discovery.

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

A spun bearing might not decrease the oil pressure at all. The spun bearing can be obscuring the oil hole in the block if it is a main bearing, although a rod bearing is more likely in which case the oil is well distributed throughout the engine at that point and a spun bearing shouldn't be able to pass enough oil to drop the oil pressure to abnormal levels.

A spun bearing will often give the clunk-clunk-squeek sound as the rod moves around on the rotating crank through the irregular clearance, and squeek as it is binding in other directions. One of my brothers actually drove a Capri for months this way, ... really knocked once started. The car was worthless anyway (unlike yours).

__________________

Gone to the dark side

- Jeff

Babymog
That's a good point -there is only that one little hole in the journal. Could be the half of the bearing that is still flush rotates and blocks it.

Do not use the starter before turning it over by hand first...
if you have some anomaly then you could bend a rod...

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Well, I'm back.
I have found metal shavings AND an inner bearing race in my oil pan. The shavings look like photos I've seen of spun rod bearings. I am assuming the bearing race is left over from an old style vacuum pump that wore out.
So-
Does the crank need to be pulled and reground? Could the bearing race be from something else?

The way you determine if a crank needs to be reground is by measuring it. Although I'd assume the bearings would be damaged first. Start pulling them caps. If there's a bad bearing it'll be obvious.

I got the main oil pan off and right away noticed the oil pump sprocket swinging free on it's chain -it's retention screw's head is twisted off -pump seems jammed.

All rod bearing babbet except on no. 6 has melted, but the races are still solid with no discoloration. No bearing halves were jammed under their mate. All journals are bright and smooth, with no scoring, and surprisingly, all measure within specs for the original grinding (between 47.95mm and 47.96mm) -at 394,000 miles, it seems that this crank must have been replaced at some point before I bought the car, and frequent oil changes have paid off for all the miles I have put on it. There are some yellow paint spots on the crank. I did not see any babbet squishing out of any of the Mains, so I left those alone.

I have to figure out what's wrong with the oil pump, but as far as the rod bearings are concerned, is there any reason why I can't just replace the bearings? And is it ok to assume the Mains are still good?

Sounds like you got lucky. Clean crankshaft from melted babit and replace bearings. May as well change con rod bearings. New LO pump with sprocket and chain and you are back in a game!
Plus buckets of pride and satisfaction after engine runs again!

I think the main bearings should be checked more carefully as well.

And a thorough flush of all oil-lubricated parts including the oil cooler to be sure that there aren't pieces of metal hiding in there, check the oil pump (post-mortem) to see if it has ingested something (which could be in the system somewhere also) or seized for some other reason.

__________________

Gone to the dark side

- Jeff

What would be the best way to check the Main bearings? Would removing the cap and looking at the bottom half be adequate? I don't think I can get a reading on the journal without dropping the crank right?

Babymog -what would be the best way to flush those parts?

Clambake my 86 300sdl was losing power the same as you described.
My engine has 380,000+ on it. I thought I was running out of fuel.
Then my six cylinder turned itself into a five cylinder at 70mph.

You might want to pull the pan. Yours sounds as if you might save it.
Searching for a good 603 has been tiring with few prospects.

__________________


Experience : what you receive 3 seconds after you really needed it !!



86 300SDL 387,000? Motor committed suicide
81 300SD 214,000 "new" 132,000 motor
83 300SD 212,000 parts car
83 300SD 147,000

91 F700 5.9 cummins 5spd eaton 298,000
66 AMC rambler American 2dr auto 108,000
95 Chevy 3/4 ton auto 160,000
03 Toyota 4runner 180,000 wifes

Droping the lower half of the main bearings should allow for both a physical examination of the bearings and you would do a plastigauge check if all seems well. Hopefully they are all fine. Replacing the rod bearing shells and not checking the main bearings in your situation would not be the best.

Also cut the oil filter apart to see if metal reached it. Personally I would want to check carefully for any place some bearing babitt may have reached.

Unfortunatly just another diesel without an audiable lower oil pressure warning circuit. If a person likes their car especially it is not a large financial outlay to incorporate one. What makes it most desirable for these cars in my opinion is having those hoses in the oil pressure circuit to the oil cooler and return. Plus these engines have fairly high milage without the oil pump chain, sprocket etc never inspected usually.

Ahh -plastigage -I forgot all about those. I even remember seeing them in the "What's New" section in Popular Mechanics decades ago. I've never had a reason to use them before. Sure beats dropping the crank -thanks.

When I open the oil pump I am thinking I will find a ball bearing jamming it because of that bearing race I found in the pan. Where could that have come from -is that the type of bearing the old style vacuum pump would drop in there? Maybe I should attach a big rare earth magnet to the outside of my oil plug to catch stuff like that.

An audible warning would be a good idea, especially in a car with this many miles -I am going to look into it. Honestly I don't even remember looking at the pressure gauge when this all happened. I was so sure it was fuel related -because I had replaced that return line not 2 miles before -when it lost power, I fully expected to see fuel spewing.