95 E300D glow plugs - broke one...now what - Page 3 - PeachParts Mercedes-Benz Forum

G Tirebiter · #31 07-22-2006, 12:54 PM

I just replaced all 6 glow plugs in my 95 and found that 5 of the six came out with nary a hint of a problem. The sixth however was a bear. Having heard about breakage problems, I was not at all happy when upon the first turn of the wrench, the recalcitrant plug emitted sharp pings of resistance. Subsequent turns revealed a persistent desire to remain in place.

I briefly considered abandoning removal of this plug but the situation had quickly escalated to a me vs plug mentality.......out came the WD40. The project had begun as an IP valve o-ring replacement so between o-rings I doused the plug with WD40 and gave a couple of turns, then more lubricant. With time I was able to back the plug off of all threads however, it was still very snug in the well and could not be pulled out.

At this point I didn't know how I was going to get it out and considered starting her up in hope of using the engine compression to my advantange (did you know that the engine will idle quite happily without the intake manifold in place? Cool to watch intake valves operate...). But with IP project still ongoing, I decided to apply more patience, more lubricant, more turning, repeat.....and finally the bugger came out.

Hopefully I will get another 200k out of these plugs and not have to deal with them again.....

aklim · #32 07-22-2006, 04:50 PM

You know, it costs $10 and a couple hours work to make sure it doesn't. Why not? I mean, what does it really cost? A gasket and that is about that. Besides, you can clean your intake out and not have the oil crud in the intake. Gotta be worth something.

nhdoc · #33 07-22-2006, 05:20 PM

I agree that the glow plugs should be removed and checked every year or two to prevent problems, reinstall with anti-seize and clean the intake while its off, check the injector lines, fuel lines and return lines...these are all good things.

Also I suggest tackle the job when the engine is HOT, as soon as you shut it down remove the intake manfold and get right on them...parts always come apart easier when hot and when mine were done on a hot engine all 6 came out without a hitch. AFAIK they were the originals in there for 7 1/2 years.

aklim · #34 07-22-2006, 06:06 PM

I did mine a year and a half after I had them done previously and they had no issues. This was with 55K added to the clock. There was about 65K when I got it and it siezed. I made the mistake of trying to drill it out instead of a head job. In any case, I had them disassemble the thing and I saw there was not that much carbon in the prechambers that could have siezed the plug. Once we drilled out the threads, the plug came out easy. Unfortunately for me, it was drilled at a wrong angle and I needed a machine shop to fix it.

#35 07-23-2006, 09:49 AM

I have a 1996 e300d. Similar story. A few years ago I replaced all 6 plugs. No problem. I had another one go bad this past spring (I guess because the GP light and CE light came on). Four of the six came out fine. One creaked and squeaked on it's way out. You could tell there was some sort of major friction. The 6th seemed to turn fine but I noticed it wasn't backing out of the head! It just kept turning and turning and that is when it dawned on me that the damn thing was broken. The compression seal is still good but that plug is "in there" . Debating the next move. Once I square it away, I will be removing them on a periodic basis. I don't have a reamer but I will get one. I have 230k on the car. I'm also thinking of just leaving it in there for awhile as an experiment as to how it will start this winter here in the NE. I do hate the check engine light and the dash display reminding me of the problem though.