I own a 1994 MB S350 turbo diesel. its the W140 body and i have the original 350D engine on it. the car is giving me a hard time starting up when its cold out. its around 35 F at night and around 45 in morning. im having trouble starting it up. if anyone can help please tell me what to do.

thanks for all the help

Any record of the glow plugs getting replaced? If not I'd start with changing them. Use only Bosch or Beru, all the others are junk.

The GP light is coming on, right?


You are going to have to remove the intake, so get a set of gaskets. GP's on a 603 are not that big of a job, now that I have done it a million times I could probably do it from start to sitting down drinking a beer, in a couple of hours max. Unscrew the hard injector lines, zip the bolts out of the manifold, disconnect all the sensors, thats about it.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

There have been many posts on the subject of hard starting since the weather began to get chilly in parts of the country. All Diesels before the latest batch of CDI models have the same basic needs to successfully fire up in the cold. Read all of them.

Glow plugs failing in the more modern pre-chamber equipped, glow plug equipped models like yours have some tell-tale data that the glow plug light or your intrument panel provide as you experience plug failures. I is rare that a plug fails and you don't get a signal - the glow plug energizing/waiting period indicator light on the dash is the first of those, meaning it won't light if a plug is burned out or disconnected, etc. - and then there are check engine lights/warnings and little diagnostic sockets you can tap into to find out more.

If you don't have any indication of glow plug failures, chances are it is something else. Look through the last few pages of posts for threads with "cold starting" cited as the problem. The issues range from batteries and charging system issues to bad compression/cylinder head problems or in the case of the 350 engiine, bent rods. But you need to read up, and then look for additional, defining symptoms. 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)

I think the glow plugs continue to heat after the light goes out. Some 603 engines have optimistic indicator lights. If it is 30* or cooler let it glow for 30 seconds or more then try to start. If that doesn't help I agree on checking the glow plugs also. You may have 1 or 2 out.

Chuck