ahh operative word "properly maintained". last MB service was '99. then the local gas station mech just changed the oil as far as i can tell which is all i wanted to make sure off.
i misunderstood steve's reply and see that there is no adjustment for A/F ration which is usual on many cars these days. the car i had this same situation on was a little mitsu turbo that had a fairly sophisticated head (for its time) that had three valves per cylinder. the third valve was there to ensure a clean burn. it also didn't have an a/f adjustment. i remember the reading after i changed the plugs after it failed was way under the limit. i just draw similarities because that car also had limited use throughout the year with trips typically < 5 miles. i religiously changed the plugs every time i brought it in for inspection in the 9 yrs i had it and it never failed except for that one time.
bottom line, i guess my options are limited. i'll change the plugs and take it in for inspection. then i'll just have to go from there.
thanks for all the input.
Last edited by jsmith; 09-02-2001 at 08:56 AM.