Good news, and bad news

Well, I just got off of the phone with MB classic. I haven't been around here much lately, so here's the skinny on what I've been up to.

After tinkering around for a couple of weeks with the 190Db, I got the car legal to pass inspection. All was good with the car and I felt the need to go for a short pleasure trip. I drove a round trip of 50 miles to a friends house as I had promised to show them the new treasure when I got it home.

By the time I got home, the engine had changed its sound a bit, and was sounding very harsh when starting from a stop. When I got home, I heard the expensive sound of internal parts no longer in spec. The car had also puked nearly a quart of oil - rear main seal had failed, and in this case, apparently caused enough of a failure to effect lubrication of the rest of the internals.

Now time for the parts hunt. I had a couple of local vintage people say that they would research finding parts. After several weeks, there was nothing more than empty excuses for no information in either regard. On to the dealer. Once again, a promise to research parts with no answers in several weeks.

I finally went online to MBClassic USA, which gets parts directly from OEM. They had fairly readily available everything EXCEPT piston rings.

I received a message yesterday when I got home from work to call MBclassic. I tried this morning to call - busy and directed to leave a message, which I did not. I just called them again this afternoon. I WILL be able to get pistons with rings. It'll be the expensive way around it, but I can now proceed to do a complete overhaul without the worry of not finding that some badly needed part is not available.

So, the good news is this - I can finally fix my ailing treasure that I've been so upset about being broken so quickly after bringing her home.

Bad news is this - There is absolutely NO possible way that I'll have it ready for the November shindig. She'll have to be unveiled next spring at the spring meet. I'll have to make do this time around without a Benz to profile at the meet.

I'll take some pictures of the two beasties that I have to "put back together again" for the November meet.

[kerry]

Can you further elaborate on how losing a quart of oil out the rear main seal caused lubrication problems in other parts of the engine? What parts? Why? One quart seems like a fairly miniscule amount of oil to lose and result in major engine damage.

It isn't so much that it lost the quart of oil. It depends on when it started dumping oil. It was not doing this when I started my little drive, and was running normal at my stop at the store. At my guess, this means to me that it could have possibly dropped that quart in about 10 miles.

Think of the path of least resistance. The loss of the seal leaves a sudden unrestricted path for oil to pump out of the back of the engine. Even under pressure a liquid will take the path of least resistance. In this case, it does appear that the failure was enough to cause enough of a reduction in pressure throughout the rest of the bottom end of the engine to prevent the bearings from getting enough oil to lube properly. It got enough to keep running, but not without doing something internally. It didn't sieze or throw a rod or anything like that. I do have a pronounced rod knock down in the bottom end. I'm not too upset overall at having to rebuild the engine, as it has really bad blowby anyway, and needs the attention. I was just hoping not so soon.

[kerry]

It's posssible that I don't correctly understand the role of the rear main seal, but I don't see how a failure in that seal could reduce oil pressure elsewhere since that seal is not directly pressurized. I can see how a rear main bearing could fail resulting in increased oil in the vicinity of the rear main seal with a subsequent leak but the causal relationship would be reversed in that case. The mechanical failure would cause the seal failure and not vice versa.

[leathermang]

" Sudden unrestricted path" .... I must object to this description of the situation....

If you only lost ONE quart of oil in Ten miles.... you were no where near UNrestricted.....

You can visualize this by thinking about walking ten miles and trying to pour one quart of oil out of a container evenly over that ten miles.... It would be a tiny stream of oil which was leaving your bottle...

So , while this may have happened at the same time as your problem developed... I think for the sake of others dealing with the physics of engines... that we should point out the lack of logic in assigning this problem to the rear oil leak... if your description of the amount of oil lost is correct...so I am with Kerry on this question...

I may be off base on what I'm trying to figure is the root cause of the problem in this case. I do know that I need to get busy and get the rebuild going. I'm estimating a couple of months to do this process. I'm going the slow route as parts are not going to be cheap, and I'm on a stiff budget, and I dont think I'm going to have the luxury of taking anything back that doesn't fit correctly, and I want to get it fixed before something catastrophic fails.

What I know is this, it was not leaking oil when I got it home and started working on the electrical. I'm estimating some 50 - 60 miles of misc. driving around getting inspections, plates, tests, and just plain wanting to drive it.

It went through no noteable quantity of oil in that timeframe.

I took it on a longer exursion to visit some friends in a neighbouring town. Car ran flawlessly on the way up, and then later on the way back towards home, where I diverted slightly and stopped in Wal Mart. The car still sounded normal.

I then do my bit there and leave towards home. I pull into the small town near me (Bridgeport, TX), and stop at a light. I go to take off from the light and hear a distinct rapping sound that disappeared as soon as I was moving. Sound repeated twice more through two more lights. I get home and check oil again, it's a quart down. The underbody of the car is one giant oil slick, as was the bottom section of the engine bay. The car then leaves a huge oil slick on my driveway by the next morning.

I pulled the car out of the carport and cleaned my driveway and the engine compartment. I then park it again and try to locate the cause of the leak, and find fresh oil coming down the back of the block and pan. I shut it down and find a new slick forming from the fresh oil. I also noted a distinct rapping sound that is notably louder when I'm looking around underneath, over and above the regular diesel clatter.

At least I can fix it. Words do not describe driving one of these oldies around. If there were laws regulating the amount of fun we could all have, I would have broken every one of them 10 times over.

[Larry Delor]

Diesel Power,

A friend of mine, who has moved back to Germany and opened his own shop, told me that he can get vintage parts. ( he has an early 50's Adenauer himself )
If you want, I can forward a list of parts that you are curious about, and see what kind of $$ he wants for them.

-Larry

[Lycoming-8]

Diesel Power, I can certainly empathise with you over the engine problems that you are having. In fall of '66 was driving a '61 190Db and it developed a "rod knock". Attempted to diagnose and fix the problem, but the lack of engine removal equipment and other necessary tools forced me to take it in to Richardson's in Tulsa to get everything fixed. Ended up driving the car for another 3.5 yrs and certainly enjoyed the ride. At the time I had been under the distinct impression that the '61 was a one year only car between the earlier Pontons with the narrow grill and the later Finnies with the wide grill like my '61-Db. What were the actual years of production of this combination of 190D engine, ponton body, and finnie grill? Often had to drag the parts guy at Richardson's out to see the car before he would acknowledge that certain parts were different for this car. The 4-speed on the tree was certainly unusual as well, unless you compare it to a DKW with the inverted 4 on the tree. In late '70 upgraded to a '68 220D/8 with 4-whl disc brakes.........what an improvement that was. Must be quite a hoot though, driving a 40+ yr old MB, hope you get the '59 up and running again soon.

Originally posted by Larry Delor
Diesel Power,

A friend of mine, who has moved back to Germany and opened his own shop, told me that he can get vintage parts. ( he has an early 50's Adenauer himself )
If you want, I can forward a list of parts that you are curious about, and see what kind of $$ he wants for them.

-Larry

Sure, I'm looking at saving every bit that I possibly can:

What I can remember right now:

Rear Main oil seal
Front Main oil seal
Oil Pan gasket? (was told that they don't have one?)
Crankshaft bearings (don't know which US yet)
Connecting rod bearings (don't know which US yet)
Pistons w/ rings (don't know which OS yet)
head gasket kit (supposed to come with head gasket, valve cover gasket valve stem seals etc....)
Intake & exhaust valve guides (according to MB classic one side is no longer available & I don't remember which)

I also need a rear differential gasket as mine leaks, and also if there is some kind of gasket that goes between the air filter housing and the intake, I need one there. My air filter housing doesn't seem to tighten down sufficiently.

It is the OM621 engine.

Thanx again.

[Mark DiSilvestro]

Lycoming 8,
My (long retired) '61 180b Ponton has the wider grill and fatter bumpers. This facelift started in '59 about the time the Finback 6 cyl cars were introduced. Some sources say the ponton bodies continued on the 4 cyl cars into 1962, after the 4 cyl Finback cars came out.

Happy Motoring, Mark

I'd add valve springs to your list - either 1 or 2 per valve. I had a '60 190Db years ago that I bought from a kid that drove it all the way from Salt Lake City to Connecticut - in 3rd gear! Can you imagine going only 45MPH that distance?! He got the tranny fixed in Conn. But I loved that thing. Had it for 11 years - never a problem with the engine or drive train. Can't say the same for the body. Also, remember that it has about 115 grease fittings! Good luck.