I have a 1983 300D that I am sure has a GP problem. I searched the forum but could not find an answer for this. It has been cold and the car will not start. It is plugged in and the valves have been adjusted befor the winter. I went out to see what was going on last night. Installed a new battery. Glowed the plugs then noticed that when the relay kicked off, the GP came back on. This does not happen in my 85 TD. I thought I read somewhere that if the light stays on, it indicates that at least 2 plugs are not working. Is this true or did my brain freeze in the cold last night?

If anyone can point me in the right direction I would appreciate it. I will go out with a meter tonight and test per Diesel Giant.

Thank you!!!!!!!! Oh, Hapy New Year to all!

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Paul

1991 300TE (280,000)
1985 300TD (432,000 miles - retired)
1976 300D (225,000 - retired)
1975 300D (165,000 - retired)

Did the plugs come back on or the glowplug light come back on? If it was the light, then yes that is an indication (on some models) of problems with the plugs.

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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

thanks! It was the dash light. When I try to start the car, it feels like only one or two cylinders are trying to catch which in my feeble mind is telling me the others are not getting enough heat.

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Paul

1991 300TE (280,000)
1985 300TD (432,000 miles - retired)
1976 300D (225,000 - retired)
1975 300D (165,000 - retired)

Test the plugs and the wiring from the plugs to the relay with an ohm meter. It only takes about 5 minutes and will tell you a lot.

When I had 2 that were "out of spec" the light would not come on at all. Mine are all less than .7 ohms now and cold starts are surprisingly easy.

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AJ

1985 300D (SOLD)

I will be out in the cold with my meter tonight!

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Paul

1991 300TE (280,000)
1985 300TD (432,000 miles - retired)
1976 300D (225,000 - retired)
1975 300D (165,000 - retired)

Your problem may be similiar to mine which I am discussing here: http://www.peachparts.com/shopforum/showthread.php?t=268655

I have a little more troubleshooting to do, but I think I'm getting close to pin pointing my problem. I'll post to my thread once I have things figured out

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Pictures of the MB: http://s230.photobucket.com/albums/ee41/EricandRobyn/1981%20Mercedes/

1981 300 SD with a Goldenrod water block and Injetor line heaters. EGR is missing

1999 F-350 with HP X-over, Dahl 100 Fuel Filter, Coolant by-pass filter, CCV mod, Tymar intake.

Both on single tank WVO blend

unplug plug at relay (drivers front fender) clamp test light(looks like ice pick) lead to fuse (metal bar at end of relay) touch block with point to make sure light works. now touch each lead in the plug if light lites glow plug (and wireing) is good. if they all dont light touch the end of glow plug at head. if no light that glow plug is bad.

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His 2000 TDI Jetta 5 speed
Hers 2002 TDI auto Beetle
Toy Mercedes diesel powered 1995 Jeep.
Work 2003 Cummins quad cab 1 ton

thanks guys.....will be looking tonight

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Paul

1991 300TE (280,000)
1985 300TD (432,000 miles - retired)
1976 300D (225,000 - retired)
1975 300D (165,000 - retired)

This won't tell you if a glow plug is good or bad, just that you have continuity. You could have a plug at three or four ohms of resistance and still have a light. If the plug is open or very high resistance (20+ ohms) then you are correct, but this is not a definitive test. A meter between the plug connections and ground will give you a more definitive idea of the condition of your wiring and plugs.

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mjk

'84 300SD 119KMi (Liesl der Diesel)
'84 300D 326KMi when the oil left (former parts car)
'82 300SD 253KMi (new parts car)

yes, I have a meter and will be checking per the Diesel Giant procedure. I have ordered new plugs and hopefully the will be here tomorrow.

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Paul

1991 300TE (280,000)
1985 300TD (432,000 miles - retired)
1976 300D (225,000 - retired)
1975 300D (165,000 - retired)

You are sure your block heater was working? Testing existing glow plugs before ordering the plugs might save you money as well.

ok...I finally had the weather to check and deal with this problem. First, only one plug made the grade. The other four were from 15 ohms to infinity. So, as I was changing them, three broke at the core when I tried to take the nut off. No big deal, got them out and replaced all five with good results when I tested with the meter. I then added a new block heater...the kind that goes in the radiator hose purchased from diesel giant. Also replaced the fuel prefilter which did not look good. then the big test.......it took a bit to get fuel to the injectors since I played with the filter and had the injector rail off but if started just fine and the glow plug light does not stay on anymore.

Conclusion: bad glow plugs, possible weak block heater, possible clogged filter. I think it may have been the combination that made it impossible to start when it dropped into the low teens.

Thank you all for your help and advice.

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Paul

1991 300TE (280,000)
1985 300TD (432,000 miles - retired)
1976 300D (225,000 - retired)
1975 300D (165,000 - retired)