the car is a 1993 240 wagon in which i have replaced the engine due to low oil pressure being the result of a broken oil pump and continued driving (crazy isn't it)

anyway i have the problem engine out and on a stand.

this engine while driving after the pump broke never had ANY rod or bearing sounds at all. in fact it sounded great.

a mechanical gauge revealed at hot idle 3-5psi oil pressure and at 2000rpm around 30-40psi. the oil pressure light malfunctioned which is why the owner never new he had trouble. even after driving this car with a repaired oil light it came on at idle only.

nuff said.

the pan is off and the rod bearings reveal wear towards but not into the copper BUT the crank is smooth and shiny at all points where the rods connect.

the mains are worn but not to the copper and the crank is smooth and shiny.

my question is: based upon this data can i replace the main and rod bearings without sending the engine to the machine shop?

what about intermediate shaft bearings? is this normally a problem?

the cam journals look good with no scoring.

for the miles that were driven post oil pump break i can only assume oil was delivered via splashing yet the top of the engine does not appear to look oil starved.

anyway, informed feedback appreciated

In this part of the country 240 die from rust. Engines are dirt cheap(or
whole cars for that matter) with b230 being so robust I would have much more
confidence in a used engine than rebuilding,repairing,much cheaper too
--
Rene

normally i would agree with you and have acted upon that presumption for some time.

in fact the engine that went into this was used with low miles and cost 300. not super great but no too bad either.

however in looking over this engine with the bad bearings and nothing else wrong.... a set of main and rod bearings will cost me together $101 dollars and both sets are glyco (aka: federal mogul) so in this case replacing the bearings to get a sound engine with known low miles is worth it.

I agree with you.

I would "roll in" (install) a new set of mains and rod bearings.
To be safe, and for peace of mind, I would plastigage the clearance on all of the new bearings.

I had a freind who owned a BMW 325, and one night (after having a few too many), ran off the road and hit a culvert that was just high enough to fracture the cast aluminum oil pan and break the oil pump off the engine.

Being too drunk to drive, he proceeded anyway to continue on home, which was about 5 miles.
The next morning...still partly drunk, badly hung over and not remembering what had happened, he started the car and noticed the oil light on. He checked the oil, and finding it empty, poured 3 quarts of oil thru the engine and out onto the ground.....which he also didn't notice.
He then proceeded to my shop (which was another 8 miles) where I realized what had happened.

He asked me if I would repair the engine, and I said I "only if I don't have to pull it"

I removed what was left of the oil pan and removed the Main bearing caps.
The journals were shiny and still looked like new.....I couldn't believe it.
I pulled the rod caps, and they looked the same.
I then pulled the valve cover and inspected the cam journals.....No apparent damage there either.

I came to the conclusion that breaking the oil pump was the only thing that saved this engine.
If the pump had continued to operate while dry, it would have blown all of the oil out of the crankshaft and out of the bearings.
Since this did not happen, the oil film that remained lubricated the crankshaft, and cam bearings.

I went ahead and installed new standard bearings (which I did plastigage....every bearing clearance was within factory spec.), installed a new oil pump, and got a used oil pan at a salvage yard.

After I got it back together, the engine fired right up and ran quiet with good oil pressure.
The owner drove the car for about 2 more years before it was sold.

My point is to go with what you can see and measure, and not on what should have happened.

Just my opinion
Hope this helps
steve

hi steve

never thought about it until you mentioned it. this oil pump snapped off the result of a rock into the pan. the oil that remained stayed there for the same reason as the bmw........inertia

... oil pump broken off...

I removed what was left of the oil pan and removed the Main bearing caps.
The journals were shiny and still looked like new.....I couldn't believe it.
I pulled the rod caps, and they looked the same.

The first Corvette, 1953, was powered by the 'Blue Flame Six'. Obviously a six cylinder. The crank brgs were splash lubed, no pressure on those babies!

absolutely no scoring on any of the bearings or crank surfaces.
even the inside the cylinder walls have their cross hatching intact with no vertical lines.

i was quite surprised but happy to find this.

the rod bearings are all burnished with drak gray mottling throughout. the mains are worn but uniformly shiny and same silver like color. the rod bearings took the brunt of the low oil pressure.

the crank has quite a bit of brown colored dried oil on the turning surfaces front (1) and back (5) with minimal in 2-4.

i did find that there was a small slit in the oil o ring that set into the block. clearly this greatly contributed to the low oil pressure idle.

on a side note, once i removed the crank and all bearings leaving only the rods and pistons remaining the piston oilers in this very late production run 93 engine are clearly visible.

according the chasis number it is among the last 2000 240's ever built

Actually, after writing my first response, I reread one of my M-B owners manuals that I still had and it read that 5 psi is minimum [psi roughly converted from the M-B's actual "bar" scale] -- I had remembered that my cars all showed about 10 psi, which confused my recollection.

So I'm not surprised that your car, with 5 psi at idle, was just fine, not to mention the oil squirters helping a little, too.

Very cool! A squirter block that lives to see another day. I define spooge as any liquid or previously liquid waste or leftover, as compared to swarf, whose accurate definition has already been given above. But that's just me. Enough semantics.

You'd be surprised how little oil pressure is needed at idle speeds ....

I used to own some older Mercedes (1980's and early '90's) when they all had oil pressure gauges. At first I was surprised at all these cars' gauges behavior: about 10 psi at idle, although they all pegged over the top of the scale (~30 psi) when revved over about 2,000 rpm.
[btw, all this is converted from the M-B's metric scale]
Then I read their owners manuals, and they all stated, in black and white (so to speak) that about 10 psi was considered normal at idle; and the gauge should peg when revved above 1,500 to 2,000 rpm.

So it looks like your pressures at idle wasn't too bad, only about half of a M-B engine's idle pressure.

And if you were using synthetic oil, I'd guess you have nothing to worry about.

thanks for the replies.

i am going to clean up the crank of dried oil and install a set of std main and rod bearings.........plasti-gauge to verify all is good and button it up.

what grade of emery cloth is suggested to clean up the crank?

1200 with oil. Do you have the crank out ? If you don't, it could be hard to get the spooge out of the oilways. Otherwise carb cleaner ( the real deal flammable stuff ) and denim.

Greg

(:-) spooge ? (:-) that a nice word but the proper term in the machine trade is "swarf."

Swarf, also known as chips or by other process-specific names (such as turnings, filings, or shavings), is pieces of metal, wood, or plastic that are the debris or waste resulting from machining, woodworking, or similar subtractive (material-removing) manufacturing processes. Swarf or chips can be small particles, such as the gritty swarf from grinding metal.

I googled it and the definition above goes on but Spooge does not sound any cleaner!

FYI
On grinding machines a magnetic drum turns slowly while partial submerged in the surface of the coolant sump. Most of the swarf floats on top of the solution. The drum has a scraper blade attached to the outer surface and pushes the captured swarf off into a lump or pile into a trough.


I have a engine on a stand too. Been thinking about popping the pan for a look see. I have never heard it run as I got it out of a PNP w a five speed years ago. Supposedly?, it might only have 132K on the whole works!
I am more worried about piston slap but I do not know how one could check for that with out yanking the pistons for measurements.

Does anyone?
Phil

My opinion is you are probably OK, but to replace the main bearings, the crank comes out. My engineer background says take it to the machine shop and check it for peace of mind. I don't like repeating big jobs, so tend to take a more conservative approach. If crank is within tolerances slap it back in, if not you can decide from there. Should be minimal cost to have shop check crank journals. Mike

3-5 psi at idle is minimal, but probably sufficient. 30 psi is plenty. With no scoring on the crank, if you stick a new set of rod and main bearings in it ( and fix the oil pump ) it will be better than it was.

As mentioned before, it would be nice to check the crank for oval journals, but if they were, would it be worthwhile having it reground ? Would it be any worse than before the oil pump failed ? My guess is the answer to both questions is 'no'. The engine is already on a stand, what have you got to lose ?

How did the oil pump fail ?

Greg

here is a first:

the owner says he hit a rock on a long grass/dirt driveway.

he obviously hit it pretty hard because of the crease in the oil pan and the rack being separated from the cross member.

when i opened the pan the pump was laying in the bottom sheared from the block where it bolts in

Sounds like the bearings were getting enough oil for them to survive fairly unscathed. If they had a little wear this might have helped them survive the low-oil flow a bit better.

With no signs of damage, I'd replace the rods and mains and call it a day.

I wouldn't bother with the int shaft bearings, they're a pain to replace, plus they wear less, and as an additional point - they seem to be very hard to find right now.
--
'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)

you have to measure he journals of the crank to be sure. green plastigauge and new std bearings would be 1 one way, another would be a set of micrometers. good luck, chuck.