well, thanks for clearing up my question about when to change my oil, lol....................but seriously, WHEN should i? i have a 87 300 td wagon, i did first oil change with delvac 1 at 1800 miles, i will do the nest one at 3000 miles and the third one at 5000 mile and THAT 3rd one i will do analysis, is that good?

The statement that oil technology has improved drastically is valid, but let's not forget that some of our cars are 20+ years old. A brand new gasser Mercedes won't put anywhere near as much as stress on the oil as our beloved W123 diesels and that's part of the reason for the extended drain intervals on newer cars. You're correct about newer MB's requiring synthetic (98+ model years if I'm not mistaken).

kobeck, your plan is AOK. You don't really want to do analysis on the first change (maybe two) after switching a car that has been on dino for years, because it will flush out some old buildup. That could skew the analysis results. At the second or third change the data should be good. Assuming you analyze at 5k and there are no abnormalities, you generally base your interval on the soot percentage, figuring 2% as the general limit. So if the analysis shows 1% soot at 5kmi, you can estimate that a good interval is ~10kmi, when the engine should kit ~2%. Disable the EGR if you haven't already, btw.


DA, I understand what you're saying about our older cars being harder on oil, but don't completely agree. ;) I also don't have hard data to refute the notion so the following is my opinion. The newer diesels produce less soot, so they can safely use the relatively high FSS interval. Hence the MB FSS upper limit near 20kmi (!) where many of our older MB's probably shouldn't be going past 10-15k. Gassers are a totally different story, they can often go 20k+ (all this is assuming non-severe service). I do think 616/617 are harder on oil than 601/602/603, which in turn may be a little rougher than the new 606 engine. Anyhoo, IMO it's a good idea to do at least one analysis on your engine so you have a rough idea of what's happening inside... :) :)

WHAT IS THE EGR ???

Exhaust Gas Recirculation...Which there seem to be many thoughts about what to do with it. It's an emission control that I kept seeing people here disconnect, and put one of these;) next to where they say they only use the car offroad. But I'm all for cleaner air, and if it's not working right fixing it. By controlling the amount of exhaust gas put back in the intake it cut nitrose oxide (NOX) one of the sunlight reactive gasses that make smog, but if there's lots of blowby dumps too much oily, sooty reside into the cylinders. I just going on second hand info, so anybody have more info?

how do you disconnect it?

Put a BB in the vacuum line which runs to it :)

If your EGR is working properly and seals tightly, the BB trick is great. Better yet remove all the vacuum plumbing associated & clean up the engine compartment. The "stage 2" mod involves making a thin blockoff plate you sandwich between gaskets under the EGR for a more positive block. The final solution ("stage 3") is to totally remove the EGR and fabricate a blank plate to cover the intake & exhaust openings! Photos are here:

http://www.meimann.com/images/mercedes/OM603_intake/

Mine was leaking so I went for Stage 3. :D :D

Note that this IS NOT possible for most 1990-1995 turbo diesels, which require electronic tomfoolery so as not to make the computer unhappy and take away your horsepower. It can still be done but it's much more complicated. The turbos up through 1989 have no such trickery. ;)

And Stage 4 is to get the Euro OM603 turbo-to-crossover pipe!

Ugh. I looked in to doing Stage 4, and basically it ain't worth it. You need the complete Euro exhaust manifold, crossover, and exhaust pipes. It's not just one or two pieces, you need to do everything. They really sent a kluge to the USA. If we could find a wrecker in Europe who would sell all the parts used for cheap, it could be a neat upgrade, and also allow bolt-on fitment of the Mosselman intercooler. :D :D I think the worst part would be shipping the large, bulky, unweildy exhaust pipe(s). Here's photos of the Euro setup:

http://www.meimann.com/images/mercedes/OM603_intake/

:)

gsxr what did you use to block the hole comeing out of the exhaust? I have the plate for a stage 2 but if I could figure out how to block that hole I'd do a stage 3.

Plain ol' sheet metal:

http://www.meimann.com/images/merced...EGR_plates.jpg

:) :)