E-Class (W124) 1984-1995: E 260, E 300, E 320, E 420, E 500 (Includes CE, T, TD models)

93 300D 2.5 starts fine, then bad idle, smoke, until engine get warm, then runs great

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Old Oct 24, 2005 | 12:46 PM
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Question 93 300D 2.5 starts fine, then bad idle, smoke, until engine get warm, then runs great

Just bought a 1993 300D from down south. Here in Colorado, when cold (30 degrees F) it starts, runs fine for 20 seconds, then begins the clunking nailing sound and has heavy smoking at idle.

Once the car warms up, it's just fine, and the car runs and idles very well.

I did notice a tiny fuel leak at two of the injectors as well as some air bubles at the base of one of the injectors.

My theory so far is that the injector seals at least need replacement. Any help or advice would be appreciated.

Also, where is a good place for seals or injectors and does anyone have a link for injector removal/replace procedures?

Thanks
Bob
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Old Oct 24, 2005 | 12:51 PM
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From: Northern Cali
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when was the last time you replaced your glow plugs?
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Old Oct 24, 2005 | 01:28 PM
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gplugs

Originally Posted by NorCal124
when was the last time you replaced your glow plugs?
Just bought the car, haven't done it. However, once the car starts, are the glow plugs important?
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Old Oct 24, 2005 | 02:29 PM
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the glow plugs are to diesels as spark plugs are to gasoline engines. the best u can do right now is to begin eliminating the problems. start off w/ small things like a new air filter,fuel filter, glow plugs, or some diesel fuel system cleaner and then work from there. if you start off w/ the small problems first you're pretty much doing as much as you can before taking it to a mechanic. if funds aren't an issue, i suggest doing a big tune up first and see what happens (oil, filters, other fluid changes). but if you see that the injectors are leaking address them immediately.
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Old Oct 24, 2005 | 03:07 PM
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Question gplug clarification

Originally Posted by NorCal124
the glow plugs are to diesels as spark plugs are to gasoline engines.
I'm new to diesels, so forgive my ignorance. Beyond assistance in starting the car, do glow plugs continue to "glow" and provide fuel ignition even after the initial start?

Perhaps I misunderstand how diesel engines work. I thought that the compression in the cylinder causes the fuel to burn.
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Old Oct 24, 2005 | 03:36 PM
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I'm not an expert in diesels either but I am certain that the glow plugs are a part of the ignition system. Ignition in diesels does occur because of compression, I believe glow plugs heat diesel fuel to a combustable temp. Are there any diesel mechanics or experts out there that can chime in?
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Old Oct 26, 2005 | 11:55 AM
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Lightbulb g plugs

From what I've read on the net, the glow plugs heat the prechamber to 1500 degrees and the gp relay continues to make them glow for a short time Iin seconds), depending on sensor signals it receives. After the engine warms enough, they shut off.

So, one or mor bad g plugs could be my problem and is certainly the first place to look given the fact that when the engine is warm I don't have the described problems.
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