michakaveli

I know my 1998 E300D TurboDiesel made quite a bit of knocking when my fuel recirculation lines that jump from one injector to the next, then back to the filter body, were leaking. It would actually get worse as the car idled and warmed up.

After cleaning the mess up, which was a pretty good mess as the injectors are in a vertical orientation, and centered in the head over each piston (or seem to be, they could actually be off center but that is not visually apparent from the outside) in deep wells that filled with fuel first, then overflowed and leaked out both sides of the cover, and on the exhaust manifold. The leak became very apparent at that point. But I did note the car idled louder, and even smoked a little when it was in this condition. Once repaired (a much more difficult job on this model than the W123 units with the injector body upper half exposed) the idle noise and smoking went away.

Good luck and I hope this helps. Jim

edit: I get next to no oil consumption between Delvac 1 changes every 6,000 miles. I have now driven the car about 21,000 miles or so and I have never seen the add oil light come on. My first oil change was after 3,000 miles and I put Mobil 1, 0W-40 in it. I used this once more, after another 3,000 miles and switched to Delvac 1 (5W-40), with a 3,000 mile change, followed by an extension to 6,000 miles for the next two. The third 6,000 mile event will come in April or so. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)