diesel don,

I noticed you have a five cylinger Diesel model, and so you will have five favored positions where the starter engages the ring gear. The intermittent nature of the problem is an indication that only one or two of these positions is damaged. When the starter engages the other spots it works fine.

The starter can also make the noises if it is having a problem getting the pinion gear fully engaged before the starter motor cranks. This is usually an indication the bendix/solenoid assembly failing, and this usually leaves marks on the face of the ring gear teeth.

By now you must be getting good at taking the starter out and putting it back in. I got pretty good at it on my 240D as, until the ring gear problem was fixed, I took the starter out a couple of times thinking it was the problem.

Good Luck, 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)