My dad has a 81 300CD and the glowplug indicator light does not come on at start up and runs a little rough after starting. Up until now, the glowplug indicator light has come on and it has started quickly. Is this simply the indicator light not coming on because the glowplugs need to be changed? I have a feeling this is the case, but I would like to get some feedback. Thanks

My dad has a 81 300CD and the glowplug indicator light does not come on at start up and runs a little rough after starting. Up until now, the glowplug indicator light has come on and it has started quickly. Is this simply the indicator light not coming on because the glowplugs need to be changed? I have a feeling this is the case, but I would like to get some feedback. Thanks

Joel,

I just went through this myself about 2 months ago.....and I have to ask...did you try clicking on any of the DIY articles listed way at the top there? You wouldn't believe all the advice you get, complete with pictures and step by step processes..

I'm not trying to be a jerk here, as I know where you are coming from, but I know that some of the guys around here are just a little tired of repeating themselves.

Take a look, I bet you find the answer in less than 20 minutes.

__________________
1998 W202 C230 - The money pit of late.
1984 W126 300SD (356,800 miles) Gone to the wrenchapart
1984 W123 300D Gone to the wrenchapart
1972 W108 280SE 3.5 (sold but not forgotten)
1986 Buick Grand National 3.8l Turbo (86k miles)
1966 Glassic Model 'A' Replica http://www.glassicannex.org

http://banners.wunderground.com/weat...Round_Rock.gif

Its very easy to troubleshoot and correct. Check out the lesson below.

http://dieselgiant.com/glowplugrepair.htm

__________________
1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair

GP's bad..


Jonathan

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Blue Ridge Mercedes
Jonathan Hodgman
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Enthusiast Service, Restoration & Tuning.
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Located in the Atlanta area
Specializing in all pre and post merger AMG's including Hammers and DOHC M117 engines.
Mercedes Repair Atlanta

Why did you duplicate this thread in Tech Help???

No glow plug light at startup
http://www.peachparts.com/shopforum/showthread.php?t=159241

I had the same problem.Went on diesel giant web site,real easy to find the bad glow plug and replace it. I had 2 bad glow plugs,starts better with new glow plugs.

any chance the word - intermittant - is of description? my case. sometimes the glow plug light is illuminated. sometimes not. 83 240d. always starts. as long as i wait the 3 to 7 second wait period. key in 'glow plug position'!? whatever. punctuation.

Sounds like you have more than one glow plug out. Remove the large plug at the relay box on inner left front fender and check the pins on the plug with a DVM. You should read less than an ohm on each pin. The burnt out plugs will read infinity. You will need an 8mm and a 12mm wrench to replace the plugs.

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Auto Zentral Ltd.

'84 300TD 250K+ owned this baby since '90.

I've had only a couple incidents of no preglow dash board lamp lighting over the years. Each time, testing the GPs one by one with the ohm meter and looking for a completely shorted (infinity) reading has pin-pointed the culprit and when I replaced it everything is restored to normal. Last week the dash board light starting failing to light and from the progressively worse hard starting I was getting every day I knew I definitely had one or more GPs failed. Got the ohm meter out, pulled the connector on the firewall GP circuit box and found one showing a completely short. Two others showed 40 or 50 ohm readings. At the time I ignored them and replaced only the shorted one. Now, she starts great but without the preglow dash board lamp coming on. The weird part is if I perform the following cycle -go to position II, no GP light), wait a few seconds or until the seatbelt buzzer goes off, then back to off, then back up to II again, the GP lamp then lights up.
Now I know someone mentioned that the ohm test was not that accurate and that ANY reading above 1 ohm indicated failing or failed GP, so is my dash board lamp reacting to the two GPs with reading more than one ohm when cold?

That is probably the case.

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Auto Zentral Ltd.

Thanks AutoZen,
So that my findings may contribute to Glow Plug lessons learned, I'll post my results when I swap out the ones reading 50 ohms.