Well, yesterday the 83 300D started starting hard, run rough and puff smoke. It would do this for a few seconds then smooth out and run great. Starting warm/hot it turned right over, but cold (even in ambient 70 degree weather) it turns over hard, runs rough and puffs smoke for a few seconds. Classic bad glow plug signs.

Today I metered the glow plugs out and numbers 1, 2, and 3 all read .4 ohms, Number 4 reads 586 ohms, and number 5 reads 750 ohms. So.....I'm assuming #4 and #5 glow plug are toast. Now the question(s)

First, which ones are #4 and #5? I'm assuming they are the back two plugs (closest to the firewall) and not the front two (which look to be the easiest to get to)

Second, what is the best way to R & R them? If the bad ones are the back two plugs they look to be a little bit of a bit#h to get to. I've replaced glow plugs on my TDI Jetta and it is not too rough, but these look like they have been in the engine for the last 20 years so I don't want to screw anything up.

Thanks for any help.

Glenn

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2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)

Good assumption.


Ratcheting combination wrench.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

I remove the Fuel Injection Hard Lines so I have more room. But, that means I need to bleed them of Air when I install them.
Others leave the lines on.

New Bosch Glow Plugs do not come with the little Nuts. People have said to stuff Rages down below where the Nuts might Fall.

If the Glow Plugs are removed it is a good idea to use a Glow Plug Reamer or some alternative method to clean the Carbon out of the Glow Plug Hole. Plenty of info on that in the DIY section.

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84 300D, 82 Volvo 244Gl Diesel

I have replaced + reamed mine on my 85 300 SD without taking the FI lines off it is difficult but can be done while perched on top of the engine. Probably easier if you remove the lines but make sure you do not crossthread them on reinstallation which is what i was most worried about. It is a good idea to stuff a rag under the one you are working on so you do not lose the little nut.

To avoid cross threading screw them in by Hand before tightening.
A Neverseeze type compound on the Threads can help the come out easier the next time.

Only Bosch or Beru Glow Plugs hold up well.

I had an experience where the Tips of 2 Autolite Glow Plugs became swollen and I barely got them out of the Cylinder Head.
I replaced them with Monark Glow Plugs and some of those failed in 6 months.

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84 300D, 82 Volvo 244Gl Diesel

Had two Bosch replacement glow plugs, so after about 2 hours of playing around I had them swapped out. Car starts immediately after turning key now, no smoke and smooth idle. Looks like that issue is taken care of. Thanks for all the tips folks.

Glenn

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2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)

Two hours? Sounds like you had a rough time. I can do all five in under an hour.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Naw, the only rough one was number five, but I got interrupted twice by the wife and son needing something, so it took a total of two hours. Actual work time was about 45-50 minutes .

__________________
2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)