I was just on a long drive with my 1984 300SD and I stopped for fuel after about 4 hours driving. Temperature was in the 40s to 50s. After fueling the car would not start. The battery is new and all other electrical was functioning. I checked the fuse box, and they all seemed fine. The glow plug light went on and cycled through, but when I turned it nada. It was if the transmission was put in gear not park or neutral. I crashed the night and the next day the car started no problem in similar temperatures. I then ran the car for about an hour and turned it off, and it started again. Any thoughts? I could not find a similar post, but if you know of one. I would love to see it.

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1984 300 SD running SVO

possibly a bad coil in the starter solenoid. intermittent electrical problems are pretty hard to track down... im sure as the problem get worse, you'll be able to pin point it easier.

good luck

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-->1971 mercedes 220D; 617 951 engine, 4 speed

Could be a bad starter. Does anyone know if the SD has a junction box like the D that allows a person to bypass the ignition circuit and jump the starter under the hood? Look for a junction box on the right inner fender (?). If you have it, jump terminals 1 and 3 to engage the starter.

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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

That is good to know on how to short. I saw this post:

Procedure for Replacing Neutral Safety Switch on 126 Chassis

which indicates a similar problem. Thanks.

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1984 300 SD running SVO

I'm suspecting the engine-chassis ground strap. I went through this same scenario a few years ago and found that the bracket, the strap was attached to, was loose. I changed a perfectly good starter out, in the parking lot on a hot Texas summer afternoon, before I found out the real problem.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Thanks Sam. What does that grounding strap look like?

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1984 300 SD running SVO

I had a similar problem. After checking the ground strap, power from ignition, and the battery I decided to pull the starter and check it out on the bench. I have a manual transmission so I don't have to worry about the neutral safety switch. On the bench I was able to find a cold solder joint where the primary coil in the solenoid is grounded through the motor itself. Its just the solder joint just above the 17mm nut that the motor power comes from on the solenoid. I cleaned it us with a wire brush, added a bit of flux and resoldered it. Its good to go now and has not given me any trouble since.

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1998 Mercedes E300TD

1983 Mercedes 240D Turbo, 131bar injectors, Cosworth intercooler and 63' Ford Falcon radiator, Ardic Parking heater, Headlight wipers, Best 38.6mpg.

1973 Saab 96 Rally Car, 1.8l V4 with all the race bits

I got a lot to look at. Thanks for the ideas

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1984 300 SD running SVO

There is only one and it's BIG, about 00ga. and near the starter.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Next time it wont crank, run jumper from hot battery terminal to starter hot input, that will isolate starter.

Im betting bad starter, and you are lucky enough to at least get some warning that its going. Replace now or beware.

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Paul
Benz-less
I need an SDL !

It seems that the car starting intermittently indicates the solenoid and or Neutral Safety switch. Thanks everyone.

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1984 300 SD running SVO

Check the neutral safety switch, possibly your shift linkage bushings, they're known to do this.

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

possibly a worn out starter...mine just died this weekend. last few starts were kinda like a weak battery...then after about a dozen weak starts over 2-3 days it finally quit...starter clicks but no rotation. jumping did nothing and voltmeter shows a stron battery....pulled and tested, tested "ok" on the bench but we could see it turning real slow and very weak...enough to pass bench test but it's practically dead...

classic hot starter problem...heat increases the electical resistance...makes it hard for the starter to run...that's why letting the car sit and cool down sometimes helps...when copper gets old and corroded the resistance goes up over time...eventually needing to be rebuilt....

i'm guessing that was my problem and might be similar to your problem.

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1987 300TDT
1981 VW MKI Caddy 1.6 diesel, waiting on engine swap
1983 D-50 Power Ram 4x4 "Mitsubishi" 2.3 turbo diesel
assorted gas powered crap and motorcycles

RIP: 1984 300TDT, 1982 300TDT, 1984 190D 2.2, 1992 300D 2.5, 1987 300TDT, 1982 Maxima LD28, 1983 Maxima LD28, Isuzu C223 P'ups X3, 1983 Holiday Rambler 6.2 Banks turbo diesel, 1984 Winnebago LeSharo 2.1 TD, 1985 Allegro 6.5

I have the hot starter problem from time to time.. When I'm not so lazy I'll replace it. Probably have to strand me somewhere to motivate me.

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'79 300D, Ivory "Gunther" ......going
'81 300SD, Metallic Blue Silver, The Grey Ghost.....going
'87 300D Turbo ...gone
'05 CDI.... gone

I have the same issue. I have never been stranded though. I get my car jack out and a couple hard bangs on the starter and starts right up.

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VegStew
1983 300SD 70,000 WVO Powered miles
1990 300D In driveway with Head Off - Cracked