lately its been taking a long time for my car to start. i almost always have to crank it for about 2 seconds, even if its still warm, but every once in a while it starts right up. the car runs fine after a few minutes, but occasionally there is alot of smoke when i start it in the morning (gray smoke). i just had the oil changed and it is still doing this. my glow plugs seem to be operating normally. could this be a compression problem? bad fuel? something else? it wasnt doing this 6 months ago. it seemed to start when i changed to Mobil1 0w-40, but ive changed it back since then to 5w-40.

thanks

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1991 300 D 2.5 Turbo, 220k
also in the family:
1981 240 D 185k
1991 350 SD 185k
2006 S 500
2005 SLK 350

Small leak in a fuel line letting air in?

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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

How have you checked the glow plug operation? Have you checked the resistance of each individual glow plug? My opinion is that individually checking each plug, and checking for voltage at each glow plug while the relay is on is a good place to start.

SteveM.

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'93 190E/D 2.5 Turbodiesel 5-speed (daily driver)
'87 190D 2.5 Turbo rustbucket - parts car
'84 Dodge Rampage diesel - Land Speed Record Holder
'13 Ram 2500 Diesel
'05 Toyota 4Runner

After verifying the plugs are good, I'm with Kerry... might have a small air leak in the fuel supply lines (near the IP).

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This is the most likely issue on your make, model.

Do a search, many others have had this issue.

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1985 300SD
1983 300D
2003 Volvo V70

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i had all of the glow plugs replaced in the winter and the light is working like it should, thats good enough proof that they work for me. the glow plug light comes on usually when even only one of them is out.
the fuel line idea does make sense though. i ran diesel purge through my engine a while ago so i had to disconnect the fuel line. perhaps it has come a little loose.

thanks alot, thats the first thing ill check.

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1991 300 D 2.5 Turbo, 220k
also in the family:
1981 240 D 185k
1991 350 SD 185k
2006 S 500
2005 SLK 350

Don't be so trusting. These glow plugs are capable of failing at anytime, sometimes all at once. Besides it only take three to quit and they just won't start. Two, if it is wintertime.