New member - and help needed already
 

Well first of all, I suppose I should introduce myself - Michael S., and I'm running a 1986 300sdl, the body's got 308000 on it but the engine was replaced with a +/- 160-180,000 mile engine back at 285,000 miles on the body - unfortunately I haven't got records on it for anything before we got it. It hasn't been cared for TOO greatly but it's in decent shape, and my dad (who is a lot better at DIY than I am, but I'm learning) and I have been able to improve it a lot over the last year. I'm listed as "mssdoglover" over at the Benzworld forum if anybody's noticed some of the issues I've had with the car over there :D

About me... 17 yrs, old, always wanted a Benz for a first car even though I'm in a Ford family... i have no idea why but I'm glad I've got the old girl, even if we do have some trouble every now and then.

Which brings me to my question - I've worked through a lot of issues, but I need a little more help with this one.

I've attached a picture of my #1 fuel injector, but #2 does this sometimes as well: I have motor oil (Rotella 15w40 dino) leaking out... at the base of that injector. I painted a red stripe along where it leaks out in the picture, but it basically comes out all the way around, not just under that stripe. 1. Why would there be oil there anyway? Doesn't make sense, if anything, shouldn't it be fuel leaking there? 2. How do I fix it? 3. How big of a problem is it?

We can't figure why in the world oil would be there. I'm not having any trouble with the engine, other than the leakage - and it's not a fast leak at all, it's just I occasionally notice slow air bubbles in the oil pool there, which means it's still leaking, and everything is pretty oily under there.

Hate to come in firing off questions, but does anybody have any ideas?

P.S. I was REALLY shopping for a 300SD with the more bulletproof (as I hear) 617 - but this was about the only specimen we had access to that had a halfway decent (meaning a few years newer, therefore less abused) interior... it was a toss-up. I'm just hoping it lasts several hundred thousand miles, or a few more at least - I'm a senior now and I'm planning to take this thing through college if it'll get me there.

Sorry for the false alarm... maybe I'll get the picture THIS time.

OK, I agree it is odd that oil would be leaking out of the injector area, (i am guessing the PC area, but I see no pictures, so...) anyway, you may have a valve cover leak soaking the injectors with oil, and a pc leak making bubbles of combustion gasses. just a thought.
John

How much oil does the engine burn/leak?

It's hard to say. I have NEVER added more than one quart in between changes, and I did that at 3500 or 4000 into my 5000 mile interval. I believe that that missing quart was leaked instead of burned, because there were a few oil changes over the summer when I drove those 5000 miles within a month or two - when I did that, it was still right where it belonged on the dipstick when I changed it. The time I had to add a quart was during a cycle in which it took several months to go that mileage - so I'm assuming that it leaks a quart in a few months and burns only a negligible amount.

Valve Cover Leak
 

Looks like a classic valve cover leak to me...

Me too. Clean it up real well and watch.

Feel the bottom of the junction between the crossover pipe and intake manifold. It's common for oil to leak from that joint onto the injectors. It's a whole other can of worms why there's oil in the intake manifold but that's common too.

The bigger problem IMO is air bubbles. That suggests you need new injector seals or, heaven forbid, to get the prechambers seated properly.

Are you sure it's not a fuel leak? How old are the return hoses?

Sixto
93 300SD 3.0

"Feel the bottom of the junction between the crossover pipe and intake manifold. It's common for oil to leak from that joint onto the injectors. It's a whole other can of worms why there's oil in the intake manifold but that's common too."
I'll check when I get out of school... but I don't think it's there because I think Id've seen it. We had the crossover pipe off about six months ago for something - and it wasn't a LOT but there was a little oil in there - not pools of liquid or anything but there had been a little oil blowing around in there. What does that mean?

The bigger problem IMO is air bubbles. That suggests you need new injector seals or, heaven forbid, to get the prechambers seated properly.
Injector seals, possibly. I doubt the prechambers have ever been out, judging by the lack of other maintenance that it seems to have been given previously. I could be dead wrong though. It doesn't violently bubble or anything, it's just every 15 or 20 seconds, sometimes, I'll see one break loose through the oil puddle. I haven't watched it enough to know a pattern yet.

Are you sure it's not a fuel leak? How old are the return hoses?
The return hoses are old but I don't know how old, and I scooped up a fingerfull of the leakage after it cooled off a day or two ago and it definitely doesn't smell or feel like diesel, it's exactly the consistency, odor, color, of the Rotella that I drain out when I change the oil. I'm pretty sure it's not fuel. We've had a fuel leak before, and when that happened, the cleaning properties of a slow drip of diesel running down the engine kept things sort of de-greased - it's definitely dirtier oil coating the thing now.

Are these just, in general, overdue maintenance problems that I can eventually work out, or is all this starting to add up to my engine being on its way out or something like that? :confused:

All the story we know on the car is that the reason it (supposedly) has a different engine in it was that one of the many previous owners drove it across Greensboro, or partway anyway, with a broken fan belt. Needless to say, this being a 603, the old engine was unsalvagable (so we were told). We bought it from a "dealer" in high point who seems to get wrecked and abused ones, in addition to some nice ones, fix them up well enough to resell, and then move them on, at a decent price, to people. Basically he's a used car salesman who happens to specialize in Mercedes. He knew enough about them to put it together, though - we've found a few loose ends he left us but we've fixed them all. Long story short we got what we paid for, and it's doing OK - but it's stuff like this that makes me think he wasn't too great at going above and beyond on maintenance. I get the feeling that this car has been "kept running" for more of its life than it's been "properly maintained" - I'm undoing what I can as I find it.

you're not TOO far away, if you need some help and you are down this way, drop me a line... my shop is pretty sweet for a homeowner.
John

I like this theory.

Welcome!

Im 17 and a senior in high school as well. This forum has been a wealth of information for me, as I am sure it will be for you.

Glad to have you here.

Just out of curiosity - and if you don't consider the question too nosy - would this dealer happen to be "Lloyd's of High Point"?

Not nosy at all - and yes, that's where we got it.

I don't blame him for much of what's gone wrong; even though there are cheaper ones out there I feel like he gave us a fair price on it, decent anyway, and he didn't claim it was anything that it isn't. We paid our money, bought a used mercedes diesel, and inherited problems just as we would have anything else - but it's been on the road for a vast amount more time than it's been in the garage, so by that account it's fine.

I enjoyed walking through his yard just looking at all the Benzes out there - we went up there about four times before we picked one out.