OK, folks, help me understand some MB diesel basics here, if you don't mind. My 73 300D was a bear to start in the cold unless the valves were lashed just right. As I understand it, MB went to a hydraulic head a bit later, and decreased cold-start issues by doing so. Opinions on this? When, and on what models, did this change take place?

Thanks!

Chris

Chris,

I think this started with the original W201 190D in 1984, and continued with all new models thereafter (1986 300D in the W124 body, 1986 300SD in the W126 body, and all later diesels in all bodies). I think the biggest help for starting included bigger starter motors, higher temperature glow plugs, and on some models, fuel line heaters. The W210 models come from the factory with Mobil 1 synthetic motor oil, which also helps.

The higher temperature glow plugs were installed in the W123 Diesels at some point as I know the 1982 unit we have is equipped with much better plugs (sometimes referred to as "pencil" plugs rather than the old "loop" type plugs) than the 1975 240D. I have replaced the starter in the 1982 unit with one from FastLane listed for a 1985 300SD/300D and designated "heavy duty" along with Mobil Delvac 1 engine oil and good engine mounts, which all contribute to an original engine with 312,000 miles plus on it starting in zero degree Fahrenheit weather reliably.

The valves on my older cars were always adjusted and the 1975 240D was never as easy to start in the cold. I attributed that to the power consumed by the glow plugs and the less than snappy performance of the starter motor. My 1998 E300D TurboDiesel starter motor winds that engine over at a very high speed and that car starts in less than a second after twisting the key regardless of outside temperature. I think the starter motor would be good for about 20 mph if you could engage the transmission in Drive with it running.

So, I think the message is there have been more improvements than just the valve lash changing to a "maintenance-free" version. Good luck and I hope this helps, 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)

Jim -- your reply helps VERY much... very thoughtful response, and hard to find any argument against any of it. Thank you!

Chris