Finally got to the point where I had lost 2 glow plugs and couldn't get the car started without much cranking, smoke and drama. Pre-glow light was also not working.

Took to the dealer (I've screwed up my back to the point where "shadetree wrenching" by me may no longer be an option...) Told them to replace all glow plugs and ream the bores. Runs GREAT when warm. Started cold yesterday morning (although preglow light did NOT come on initially) started promptly but there was a definite miss/rough run on one cylinder for about 15 seconds and some white blue smoke. Shut down and tried to start again and the preglow light DID come on for the second attempt...

Took the car back, they found a leaking cloth/rubber injector return line (replaced them all) and said to try again at cold start this morning. It IS actually better today- car started promptly but it would briefly "cough" intermittently for the first 15 seconds (maybe 8 "coughs") few puffs of smoke, then ran smoothly- though AGAIN, preglow light did NOT come on initially. Again, as yesterday I shut down and tried restart- glow light came ON for the second attempt (as it did yesterday), then started and ran fine.

Any suggestions on what this could be??...bad preglow relay?? Glow harness short? Hate to complain about what is a seemingly small hiccup...is it worth following up?

Thanks,

J.G.
Any suggestions on

If the light's not coming on initially, something is wrong. Don't know what it is, but I'd take it back and have them fix it. Could be as simple as a poor connection.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

What kind of cold starts temps are we talking about here? If you are close to 0 or below, your engine will not like starting cold even though you get it started.

If it is cold, coughing, smoking, missing is the norm. Best to plug it in when it is cold.

But as Kerry said, it seems there still is something wrong with the glow plugs/relay. If the light comes on at least some of the time you can rule out a bulb. I would then move to the relay box and check the connections there (with a multimeter). Then on to the glowplugs themselves. Check to see that the box is getting voltage all the time and each GP is getting voltage every time you energize them.

I know you said you couldn't do it, but whoever you have do it should check into this.

__________________
2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

Ambient was about 30 degrees at start this am vs. about 24 yesterday...not terribly cold. I've tried different bulbs in the cluster- all work fine. It was just an exact repetition of behavior for the last two days- no glow light first try (start after counting off 15 seconds). start, run about 20 seconds, shut down, try again and the light glows for the second try.