I purchased my 1998 E300 with 16K miles in 1999. Since that time, I have put 63K miles of primarily city driving (with a few long summer trips) on the car. I change the Mobil 1 5W-40 every 5K miles religiously. Driving to work and back (about 12 miles), I rarely push the engine above 3K RPMs. This weekend, however, I noticed a large cloud of black smoke while merging semi-aggressively into traffic. I accelerated subsequently harder to see if it would happen again, and each time the engine was pushed to about 3.5-4K RPMs, smoke would appear (during the daylight, by the way...not in the headlights of cars behind me). I have read that sometimes the hardest driven diesels hold up the longest and that the Italian tuneup is not always a bad idea.
Is black smoke normal from a well-maintained, calmly-driven OM606 E300D-T? Also,
What is the proper way to burn off these "deposits" - for example, is using gear (3) instead of (D) on the highway for about 5-10 miles sufficient to "clean-up" the engine? Is there any risk of harming the engine or 722.6 transmission in this vehicle...Is an Italian tuneup beneficial on a newer diesel like the 1998 or more suited for W123 OM617s? Sorry for the long post and maybe frivolous concern.
05-20-2007, 06:22 PM
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