Can the 617 injection leak into the oil?
 

I'm running a 5-40 synthic and it's very runny. This is the first time I've run a synthic oil and it looks like the oil level is a little higher than when I filled it a Thousand miles ago. I fear maybe the injection pump is leaking into the oil. I had the same problem on my grandfathers tractor that ended in the death of the motor. Funny thing is it was leaking/ burning oil at the same rate as the injection pump leaked.

I believe it is possible but quite rare...how does it run?

Could the lift pump seal be compromised? This could introduce fuel to the oil. Very hard in my opinion to make a determination something is going on. Reading a dipstick in different locations will produce somewhat different results. Can you smell diesel fuel on the dipstick?

You could send out a sample for evalution. Unless it is really pretty certain. Viscosity of 5w 40 at least to me sounds a little too thin for these diesels in summertime running. It may protect like a forty weight at operational temperatures it was designed for but will not have the viscosity of a forty weight. To compound this the oil in these engines may or may not run at as high a temperature as the oil product manufacturers intended. The viscosity of multi grades increases with temperature.

If all your trips have been just around town you may have made some increase in condensate level as well. Have you been out on the highways?

Sounds like a case for some oil analysis, from someplace like Blackstone Labs.

Yes. The little O-ring in the Picture is what can cause the Leak. The Valve Kit that Pelican Parts sells does not have the O-ring.

http://www.peachparts.com/shopforum/showthread.php?t=215770
Bosch FP/K22MW22 Feed pump There is a repair kit for these pumps. Bosch part number DGK301 The kit covers FP?K KE and KS pumps includes more parts than you'll.
The above is the Complete Kit+ extras because the kit covers other models.
I bought the Valve Kit from Mercedes and scrounged up the O-ring from the local BMW Motor Cycle Dealer.
There is also some sites that sell generic kits.

The O-rings listed below are supposed to be Viton but read the thread to be sure.

Lift/FUEL SUPPLY PUMP TINY o-ring
Bosch lists now 2 440 210 002 (MB 010 997 86 48) as replacement to the original black(perbunan?). And yes,the replacement is Viton.
The 5mmØ x 1.50mmØ 'O' ring is located in a groove in this bore and prevents engine oil in the IP from being sucked into the fuel re-circulation circuit. In most cases this O-ring has either hardened and broken up or completely disappeared.
http://www.peachparts.com/shopforum/showthread.php?t=261822

That is a good idea but He could get a Rebuild Kit for his Fuel Supply/Lift Pump for the Cost of the Analysis and change the Oil and see what happens.

The only other place Fuel can get into the Engine is the Injectors. If an Injector was bad enough to do that I would think it would show up as some sever Nailing after start up.

Diesel911, I have a spare lift pump. Should I be able to compress the cam by hand on the bench to see if it moves or is the spring really stiff?

Possible coolant getting into the oil?

wouldnt the oil pressure be too great for this to happen? wouldnt the opposite happen, oil getting into the fuel?

Once the Pressurized Oil gets past the Tappets it is not pressurized and there is a big port at the top of the front Bearing Cap that lets the Oil Flow out.

On other Bosch Inline Fuel Injection Pumps If the little O-ring gives out the Fuel Gets into the Crankcase.

However, at least 2 Members have said that they had Oil loss and could not explain were it was going and Rebuilding the Fuel Supply/Lift Pump fixed that.

And, when I worked in a Fuel Injection Shop I have never experienced the Lift Pump sucking in Oil from the Fuel Injection Pump so for Me that muddles the issue.

However, there is only 2 Places where Fuel can get into the Engine. By way of the Injectors or the Fuel Supply/Lift Pump. So I think the OP is left with a process of elimination.

It could be that if the O-ring gets old and hard the Lift Pump Sucks in Oil. If the O-ring is so bad it is nearly gone it could he Fuel leaks into the Crankcase.

The Spring is stiff. Try grabbing the Pump and pusing the Roller or Rod end of the Pump against a Wooden Door frame. That way you can sort of lean your weight on it.
It is possible for the Piston to be rusted in place.

If you remove the 30 something mm plug you can remove the Piston and the Spring.

If you remove the Large Plug on the Pump you will not have another Crush washer for it and that Crush Washer is thin and if it sticks it is hard to remove it with out bending it. I just put some Thread Sealant on the Plug and screw it back in.
If you use Blue Loctite try to get it only on the back 2-3 threads.

The funny thing is this is the longest the motor has held oil. I just replaced the head gasket 2 months ago and I haven't seen a coolant drop. I believe I have a fuel pump in my truck I could try and see if it it helps. The motor oil smells like diesel exhaust and it taste like nothing. I figured I might be able to taste the diesel, but funny enough the synthetic Rotella doesn't taste like anything. I've sent out for a kit from the lab you guys recommended and it should be here in a week. I'm thinking about removing some oil and then marking the dip stick half an inch above the new level to see if it changes. Let's hope I'm just crazzy.

We'll I sucked out a gallon and a half of oil before it was on the right spot on the dip stick. Where can I find the sealing ring.

Not sure if this is what you mean
Lift/FUEL SUPPLY PUMP TINY o-ringBosch lists now 2 440 210 002 (MB 010 997 86 48) as replacement to the original black(perbunan?). And yes,the replacement is Viton.

A Bosch Fuel Injection Shop would be or maybe the Dealer since there is a MB part number for that

I bought a regular rubber on from a BMW Motor Cycle Dealer and had to wait a week for it at $1.75
BMW motorcycle parts 5x1.5mm O-ring, cold-start enrichener shaft, part# 13 11 1 257 819

Or you can buy the compelet Fuel Supply/Lift Pump Rebuild Kit
The Turbo Diesel kit is Bosch kit# DGK301
The copies run a totlal with shipping included about $15 the real Bosch Kit is close to $30 some add shipping some don't
The Kit for the M Pump before 1985 is DGK128 but you need to verify that as I am not 100% Sure.

I ordered the kit. its impossible for the injection pump to leak diesel into the oil right? At least that's my understanding from your posts. Only the injectors and the fuel lift pump and leak into the crank case

Almost nothing is totally impossible. The later than your injection pumps apparently develop this issue or can.

The small o ring seal in the lift pump for some reason does not come with the standard rebuilt kit. Not hard to round one up though.
If your thoughts are right just draining a gallon and a half of the base oil mix is not enough. The oil is seriouisly diluted and has to be flushed. I would not drive on it.

Berry, the Mercedes Valve Kit is not a complete rebuild Kit. It does not come with the Little O-ring, Gasket or the large Crush Washer for the Big Plug on the Lift Pump.

The Kits that others sells have all that stuff and often more as the cover other variations of Lift Pumps. The Generic Kits do not have the Glass Filter Bowel that the Boack Kit has.

Well sort of have got Me on that. There is what is the most likely normal Cause and then there is some extremely unlikely Causes.

Please note that all Inline Fuel Injection Pumps pass some Fuel Past the Element Barrels and Plungers. If the Pump is OK and the Oil is changed at the proper intervals that is never a problem.

Special Cases:
You have had previously removed the Elements from your Fuel Injection Pump and when you put them back in you messed something up.

You have an M-type Fuel Injection Pump and drip timed it and managed to get the Element miss aligned or did not Torque the Delivery Valve Holder properly.

M or MW type Pump; the Housing is cracked inside.

This is a pic of a 6 Cylinder MW Fuel Injection Pump (This means I am not sure there is an O-ring down there on the Mercedes MW). It shows an O-ring that goes at the bottom of the Element. Pulling even one Element out of an MW Fuel Injection Pump is risky because moving the Element changes the delivered Fuel amount.

The only way I know to check for a leak is to pressurize the Housing and that would also work for a cracked Housing.
While that is best done with the Fuel Injection Pump off of the Engine cracks have been know only to leak when the Item is Hot and functioning.
I have no idea what a good pressure to test at would be other than the Max Pressure that the Overflow Valve is supposed to hold something like 18 psi.

M Type Fuel Injection Pumps don't have that O-rings sealing any part of the Elements. The Element seats directly on the Aluminun Housing on the Bottom end snd the Crush Whasher seals on the top.

If the Element Plungers or the Barrels are scored from passing dirt throuh them or the Fuel Injection Pump has been in use so long that normal wear has worn the Punger and Barrel out they can leak.

Injectors:
A broken Injector Pressure Spring will cause raw Fuel to go into the Engine and it is not going to Atomize. If that happend you should have an obvious miss.

If the Injector Nozzle is worn out some of the Fuel is not going to Atomize well and over a long time it can add Fuel to the Oil. The same if the Pintle tip is burned or broken off.

But, all those are extreme cases that don't occur often and not the first places to look for the problems you have described. Some of the Someone would have had to have done some work on the Fuel Injection Pump and messed up the re-assembly.

I ordered the complete kit from eBay with the small o ring in mind. I'm not quite sure what to think though. The fuel primer pump is only two years old But I had the injection pump out of the car for a month while I replaced the head. So maybe the o ring dried up. And maybe it's been leaking for a long time and I've never held oil long enough to tell. I know my dad replaced the o ring under the elements with a step by step play from a local injection pump shop. They told him that if he marked the the elements before he removed them he should have a problem. But I never noticed fuel in my oil until now. Is there a way to check the elements in the car?

I've already pumped the all the old oil out btw. Waiting until I put the rebuilt primer pump in to test if the problem is fixed. Think 40% diesel in your oil will cause long term problems?

No point to worry about that now as it already happend. When everthing is fixed just drive the Car and keep an eye on the Oil Pressre.

If there was some bearing issue there is chance there would be something in the Oil Pan.
I have I think it is 2 posts or threads were I told someone how to mark the Elements MW Fuel Injection Pumps in hopes of getting them back into the same place. However, it was an act of desperation as they had the Upper O-ring leaking.
One of the Threads was about one Month ago.

You Did not say why Dad was pulling the Elements out and did not say if he replaced the Lower Oil Rings or eve if there is lower O-rings.

I have only pulled one Element out of My spare Fuel Injection pump and that was only to write the Post I made on how to mark the pump.
I did not see any O-ring at the bottom but I also was not looking for one.

The Spare IP is buried under a bunch of stuff in the Garage. I need to clean out that area for another project I am working on. When I find the IP I will take a better look inside for the O-ring at the Bottom.

This is a blow up of one of the Pics I took when I pulled the Element out of the MW Fuel Injection Pump. Maybe that is an O-ring down there??? I cannot say for sure.

If your IP is leaking from there you will be the first to have that issue that I have read about.

Do you know if Your Dad replaced 2 O-rings per element or just the one at the Top. If He did replace O-rings were they one from a Fuel Injection Shop or Gasket Kit or were they ones He picked out from an O-ring Assortment?

I don't know for sure if there is a O-ring at the very bottom see pic.

If I looked it up corrrectly the complete Gasket Kit for the Fuel Injection Pump is $32-$45 plus shipping. I don't think the Governor gasket comes with that but that has noting to do with Fuel leaks.

Nothing to be overly concerned about. Rebuild the lift pump and monitor the situation.

At worse if the problem persists a cheap used injection pump would be the logical next step. As long as it is removed from a car with some fuel still in it all should go well if it came to that. .

You could have far worse problems remember. One important thing is not to keep running on thinned out base oil. That can create an issue of more serious magnitude in my opinion.

The oil is the only thing that creates a coating or cushion between metals. Get it thinner and you might lose the protection. Thin enough and you will for sure.

Diesels have serious thrust loadings. Gas engines have much less. You can seemingly maintain oil pressure with thinned out oil but it is not an accurate indicator that enough protection is present. You can use a cheaper dino oil for the current checks. No sense pouring expensive synthetic back in till the issue is known to be solved.

Try to visualize oil density or viscosity as a condom between metals. Take it away and you are screwed.

Without a doubt if continued use where done. Very short term there might be some slight additional hopefully neglishable wear in my opinion.

Us old timers used to discuss diesel base oils well before many members on site where even created. I do not want to see an oil thread.

I have postulated to myself that the reason the 617 does not last longer than it does in general. On the assumption top quality materials where used in construction and I suspect they were.

The average viscosity of the oil we have used was not really adequate to the task. Taking it a bit further running on straight 40 weight or 50 weight during the warmer season might have extended the average 617 engine life substantially. Multigrades claim to protect like a straight 40 for example. They just do not hold the viscosity index as well. My suspicion is even if you had straight kerosene as a base oil. Your oil pressure gauge would still hit the upper stop.

The proof to me is if you have an engine burning oil on say 10-30. Change it to a straight 30 grade and oil consumption will drop in half or more usually. The thicker or more viscosis oil is just not getting past the piston rings as easily.

This is not subjective as I have done this several times to reduce oil consumption. You have to study the multi grade literature. They usually claim it protects like a 30 weight for example but do not really claim it develops the same viscosity. It might for all I know if run as hot as the design paremeters for it where reached temperature wise. I supect they are not in the average engine anyways.

The high viscosity is what you are depending on for engine durability to keep the metals well separated. The lesser the viscosity the more the cushion if you wish is reduced. The oil pump is so powerful in the Mercedes diesels I feel it will not warn you the viscosity is very low. I would even go as far as to say 5-40 in warmer weather might drastically shorten potential engine life.

Easy enough to get data on this one. Who has run a UOA when running thinner oils in the summer? Any indication of bearing metals?

I'll ask about the o ring tonight for you. My pump had a lot of discoloration where the element set and that what he went off of. If I remember right the o ring was right below the shims. But I was to worried that he might mess it up to watch. The injection pump guy told us that even the smallest miss alignment Can cUse a miss fire and even not run.

Not really in my opinon as the slow wear in comparison from one viscosity to another is going to be very small in differential. So it would appear to be in the normal range in general by periodic test. Or until the wear is noticeable.

Existing wear undergoes an accelerating period once well established. The only proof would be to put two engines on stands and run them in identical service cycles for a very long time with different viscosities. The average 617 block should probably be capable of close to 500k before needing rebuilt. That's if it is lubricated properly.

It is really hard to find out what they are doing with all the inacurate odometer issues on these cars. I suspect some are making it in an unknown fashion. Some of the examples I have seen have acquired really substantial milage yet the vendors try to pawn them off as 200k mile examples. I have often wondered if they still had the original un rebuilt engine in them. Based this on some of them still seemed decently strong in the engine .In my opinion if the engine had been rebuilt they might have mentioned it but never did.

It was always said in the old days that an equalization of block and head temperatures should be practiced by letting the diesel engine idle for a few minutes before shut down. .Nobody or very few practice this anymore. On the 603 engines it may still be really advisable because of their head issues. I am not suggesting it would eliminate the problem. At the same time it would not hurt either at worse. Repeated hot spots not cooled off to average engine temperatures gradually may crack at some time. The metal thermally fatigues from the stress of the unequal cooling down.

Ill keep that in mind I just demoed the pump and a lot of black thin oil came running out of the fuel pump. Hopeful that my problem

Wel I replaced the I ring. Drove it around put can really tell. I'm going to hit the interstate to see if she doesn't gain oil. But my oil is leaking again:(

I've noticed that it's still creating up. I just remembered that I switched the delivery valves around on the injection pump after the head replacement. 1 and two to see if a miss fire would move with it. Turned out to be the injection pump timing. Could this cause the problem?

If you have an MW Fuel Injection Pump the Delivery Valve holder sits above everthing and I don't see how Fuel from up there would make it intot he Oil since the Elements are almost seperate units that plug into the Fuel Injection Pump Housing.

I don't have any comments left except that if there is lower O-rings that is about all that is left.
I think removing the Fuel Supply/Lift Pump (again) and let that pint or so of Oil Drain out (again). Calmp or plug off the Cigar Hose and the Injector Fuel Retrun line where it goes into the Filter and find some way to put the Fuel Injection Pump under Pressure. You can go as high as 18 psi and see if Fuel leaks out of the hole that you removed the Lift Pump from.

I don't know if the Hand Primer can provide the pressure or not and I have never read of anyone doing this so you are entirely on your own.
I think Cranking the Engine might burst something if you try that.

I've desided to put the car on hold until I have more money and time. I've got a new 300sd coming from Cali from some very nice people that desided that they didn't want it anymore. I really appreciate the help. I'm sure I'll be back on when I get the new car. I'm thinking that I'll just have a the pump rebuilt with bigger elements