Hi all .
I still struggle with my OM621.918 cold start problem.
recent compression test is about 300 +/- 5 psi in all cylinders.
I've changed the timing chain , installed fast glow plugs , replaced the camshaft with another used one with better lobes. checked all fuel lines for air leaks. installed rebuild injectors , checked the valves ..
My 200D starts much better but with the winter temperature dropped down I am back to the my problem, whet it is <35F , my MB doesn't event think to fire at all !!
I've noticed one thing: I put motor oil into my IP about 11K miles ago
so recently I was tinkering with the lift pump trying to check the valves , air leaks , e.t.c. so I've detached lift pump from the IP and noticed that diesel oil or maybe mixture of engine oil with diesel was coming out of the opening in the IP where lift pump connects... ,
As I said I've changed oil in my IP about 11K miles ago and added a little more than needed . but when I saw that mixture of oil and diesel was comig out ... I think it was more diesel than motor oil . I start thinking
is it normal for the old design IPs or maybe I do have an internal leak in my IP ? And also I've noticed a bit of diesel fuel on top IP , around delivery valves ... I am pretty much sure that all the lines are tighten ... maybe this could course a leak ?
Ruslan

I am unfamiliar with your specific engine......but from my experience most Bosch type Fuel Injection Pumps....the only way that Fuel can get into the Lube Oil is either from where the Barrel seats into the housing or if one or more of your Plunger/Barrel assemblies is sufficiently worn to allow fuel to pass by.....those are a metal to metal, very precision fit, and if they are leaking, you will need to go to a Fuel Injection Shop.....

There may be copper seal rings or "O" rings sealing the fuel gallery from the oil sump.....these would be on the lower portion of the Barrel.....and would involve disassembly of the IP.....again I would recommend a FI Shop....

As I don't know anything about your specific engine....I don't have any clue how easily a used FI pump might be to come by......

Bottom line...Fuel Oil in the Lube Oil is not a good sign.......

Sounds like you have an independent sump on your FI pump......where you have to check and add oil accordingly......therefore you should not have Fuel diluted lube oil in your engine sump......

SB

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Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

An old German, Mb mechanic mentioned something to me once about how "when the lift pump is bad, it will pump lube oil into the fuel tank" I have asked about that statement and no one has commented and I have never had a problem with that pump so, who knows

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

I did not notice the specific year and chassis type of you car, however the IP on the 190Db ponton listed in my sig is what I would consider to be the old style. On these IP's there is an oil sump that is not connected in to the engine oil system. Periodically you need to very carefully extract the contents of this sump (vacuum?) and replace with the correct oil until it flows out the overflow. Been a long time since I have done this, so am not sure if the overflow is protected with a plug or is open. Another way to tell these IP's from a newer one is the large Red oil filler cap on the top.

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150

Lyucoming,
W110 200D engine OM621.918 . IP has separate oil sump. I have not checked oil in IP for 11K miles so I am sort of wondering if it is normal that diesel fuel somehow gets into IP or it should not be at all .
thanks

Well, I got most of the info above from at least a couple of mechanics, one being a very well respected dealer mechanic and the other a very successful indy. I don't think it was something you would expect of a new engine/IP, but after some wear, both of these fellows seemed to be saying that you need to check what is in the sump every oil change. If it is heavily contaminated with diesel, just deal with it as noted above. Did not feel they were suggesting any kind of rebuild either.

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150

Lycoming is right,you should check the oil in the IP every engine oil change...Yes,it could be worn pump element,it could be worn lift pump plunger...you can find a lift pump from a w115/w123 and install it(bolts right on)...and check after say 5000m. However,the manual says that is normal to have some leak fuel in the IPoil ,but one should keep an eye on the level because the excessive amount cold enter the vacuum governor space and thus compromise its performance(loosen the 4 bolts of the governor to let the fuel/oil mixture flow out).
Use a syringe and a flexible hose to suck out the fuel/oil also thru the oil filler hole.A dry IP takes appr.200 ml. of oil.
As for the external(top)leaks-it could be the o-rings,the change is easy and similar to that on later models(to mid.-90-ies)...
Torque sequence:
1.Tighten 30Nm-slacken
2.Tighten 30Nm-slacken
3.Tighten 35Nm
The clamps that support the nipples should be tightened to no more than 8,5Nm !!!
P.S. To prevent the Ip from exc.amount of oil/fuel mixture,you could turn down(90 degrees) the overflow drip line at the inner side of the pump...number 54 on the scheme..