W110 fintail 200D climbing issue

[rsd]

I found myself in bad situation yesterday. I own 65 W110 , 200D engine is in a good shape , new chain , camshaft ... so I live in some sort of hilly place , NJ. there are couple of roads in my local area with quite steep grades; one is 17% and another road is even steeper , I do not even know exactly. Normally I avoid these roads by all means but yesterday... (b.t.w. the name of this second road is Breakneck road )
I had approximately a bit less than a half tank of diesel fuel. I want to say that climbing this road is a real challenge for my fintail , my MBZ barely makes it on the first gear , climbing hill itself is about 1500-2000 ft and it has the steepest part on the top ... I guess 20 % or more ... so yesterday I stuck on that steepest part of the hill and spend maybe an hour waiting for my wife with SUV to pull me up the climb ... The problem was not in climbing ability of OM621.198 but its "strange" behavior I was on the 1st gear doing just under 10 miles per hour going uphill , maybe 3/4 of throttle.. and suddenly engine started knocking so badly , lost its power .. I tried to shut it off but the engine just revved up instead and finally in 20 secs it stopped. so I stuck on the steepest part of that damn hill... I honestly thought that just killed my engine .. I tried to restarted it but engine cranked very reluctantly and did not start at all ... so I waited for my wife maybe 40 mins ... so she drove by I hooked the rope and she pulled me up the hill .. later on the leveled road I stuck the 2nd gear and the engine started right up ... no knocks of any kind .. so I drove the car home myself ... I honestly can't understand this situation ... MBZ 200D driver's manual tells 34/36 % climbing ability on the first gear ... and why did my engine die .. and why it restarted later without any problem? ..I could think about these reasons: lift pump went bad ? tank stainer ? the engne's tilt was so big that oil pump sucked air ? .... so could anybody with a more extensive MBZ diesel experience explain this to me ?
thanks a lot

[barry123400]

Must have been fun. Remember if a hill could not be mastered in the old days. A rearward assault was allowed. I would post this on the vintage part of our site. They are more familiar with this series. The only thing that comes to mind is something about the vaccum pump feeding oil to the engine if the daiphram is leaking. Check the vaccum pump breather line for oil. Worst as well when one end of the car is elevated but do not remember if front or back. People reported car wanted to pick up speed all by itself. Oil ingested in that fashion might cause the engine to run noisey and sound pretty bad. Pretty well has to be that or some variation if engine has no abnormal sounds now. May account also for why the engine would not quit. It had another new fuel supply. Somewhat logical but there are other senarios I imagine as well. That hill was no fun apparently. Glad nothing worse transpired.

[tscorda]

Adjust valves then check compression. Similar thing happened on my 1977 300D, OM 617 non turbo engine. My #5 cylinder was spent.

The other thing is get is started. Disconnect fuel line bringing fuel to each of your injectors. Do one at a time. The one that does not change the idle when you do this is the bad cylinder.

Also check obvious stuff, strainer in fuel tank if the 110 chassis has one, the fuel valves. Test vacuum pump on line that goes to brake booster if the 110 chassis has one should be pulling 26 inches of HG or better.

Hope this helps, Regards Tom

[300SDog]

Fuel delivery problem it sounds like to me. And that aint good because 1st generation bosch injector pumps were known for having weak bearings. And what you suspect about crankcase oil ending up at downhill end of the sump goes double for the injector pump having its own independent sump. Also I'd check out the manual fuel flow/starter pull knob device for linkage adjust, etc. The fact that it raced instead of shutting down quickly can probly be traced to this. Am not sure how much the vacuum pump has to do with it because the engine/fuel shut off on the 200D is mechanically operated not vacuum driven. So this might be your worst case scenario - a dead or dying injector pump with pull knob mechanism running a close 2nd.

Contributing and/or alternative factors can be porous fabric coated fuel lines between the tank and injector pump also return lines, a rusty dirty fuel tank and strainer as you said, and especially clogged fuel filters.

And regarding engine noise was it knockin or nailing?? Nailing sounds like a ball peen hammer striking steel and it's fuel flow related, generally sourced to bad injector tips. Meanwhile if you ever see a good used or rebuilt injector pump for the 200D reasonably priced on ebay then grab it. At/near 150-200k miles 1st generation bosch IP bearings were weak link on primitive diesel engines as i've said.

And shortblocks on old world MB diesels are not fragile, no reason to suspect internal engine damage from what you've said. Glad to hear the car came back to life. Also great to hear about 110's out there on the road.

And gotta hand it to you, must take nerves of steel to drive the primitive diesel on modern roads. Sheer courage, guts and determination even navigating the simplest intersection has gotta be a thrilling challenge. Keep the faith - 110's are staging a powerful comeback in certain circles and old world primitive diesel versions are considered cult classics, owned and appreciated by a select and elite few who dare to take them on the road fearlessly adventuring into realms of motoring that would strike terror in the hearts of many.

Meanwhile post some pics on the Vintage Forum - aint alot of dieselheads over there and you will probly get better diesel advice here, but lots of 110 and 111 owners.

[rsd]

thanks a lot for all your replies and thoughts. ye I really like to drive this car (unlike my wife, who plain hates my mbz ). driving of w110 represents the challenge of its own and on top of that with just 55 hp or less thinking ahead becomes quite critical ... sometimes the thrill of overtaking some slow truck or merging into traffic could be overwhelming ... basically the same range of emotions as in sport car just on the slower scale ) Regarding possible courses ...
I've changed fuel filter about 3-4K ago, As far as I could remember engine was knocking, similar to if anyone attempts to start the diesel engine with a starting fluid or very advanced fuel injection maybe ... I later attempted to restart the engine but cranking was extremely slow .. I remember that when I added oil into IP I overdid it and poured a bit more oil but it was like 10K miles ago .. . maybe it was a combination of a factors ... and regarding the other fuel path ...my W110 has a air filter with an oil bath so could it be that oil from air filter got into intake manifold ? and also my engine has a good amount of blowby. it is not that extreme but enough to get an engine compartment around air filter covered with oil . I also changed the timing chain an valve seals about 200+ miles ago so valves are OK. what king of tool do I need to get to the strainer ? I saw some plug in the middle of my fuel tank which seems to need an allen key of some enormous size .. like 21mm or more ??
I never checked my vacuum pump as well .. it still has some kind of seal from the factory ... and its only purpose is to produce vacuum for break booster.. so ,Barry, you say that if membrane in vacuum pump is bad or something .. could it be another path for fuel intake ?
Now 200D runs well as I it used to run ... no knocking and it looks like anything is intact for now.

Ruslan

[mbdoc]

A 1966 200D was my 1st MB back in 1973! IT too was a slug going uphill until I installed a reman fuel injection pump from a 220D & then it was great.

[KCM]

Originally Posted by rsd

I tried to shut it off but the engine just revved up instead and finally in 20 secs it stopped

The statement about the engine getting another fuel source sounds right, and a leaking vacuum pump would be the only source I could think of. When the diaphragm goes bad, oil can get pumped directly into the intake manifold, feeding the engine with "fuel". This could also cause knocking as the liquid non-compressible oil gets pumped into the cylinders. And shutting off the fuel at the injection pump will not stop the engine. The shutoff is positive on those models and shuts the fuel off mechanically. Being the car runs fine now, I would not suspect a major catastrophe. The fact that the problem happened on the hill climb might have been a coincidence. Take a look at the vacuum pump diaphragm.