Thought I would share some good news about this job. One of the main reasons I bought this E300 is that the dealer did glow plugs twice in the past 3 years. I took this to mean they all were done and I had a good shot at not having to worry about this job...noperooni. End of Jan, #4 went then #1 went sometime in the last month. Didnt know it because I was using the block heater but ohm testing showed so. After reading many reports here and other forums of nightmares with these I prepped myself as best I could, primarily plenty of PB, engine warm-kept warm w/block heater and buying a HF 18V 3/8" impact driver prompted by bsmuwks recent thread. (EDIT:87.5 Ftlbs but still a EDIT POS:rated at 300 ft lbs maybe good for about 20)

Decided to do all six, expecting to stop if I ran into trouble before breaking anything. Put the car on ramps. Manifold came off easily, driver moved things quickly. Getting the allen bolt underneath was no problem either, just a 18" extention to get to it. Man that EGR was a mess. I used the driver again on the GPs and 2-5 came out like butter but 6 was tucked behind the oil filter so used hand tools. #1 did not budge with the driver!(Ding Ding we have a winner!)

I tried gradually bigger socket wrenches 1/4-3/8 to get #1 to move-all the while praying I wouldnt break the GP. I ended up using my 3/8 long handled torque wrench set to 20ft lbs using a CCW 1/2 then CW 1/4 step routine, with frequent PBlaster squirts and waiting for it to take. Lots of 'carbon squeaks'-nerve racking! Tedious and time consuming, but I dont think there is a fast way to remove a stuck GP. Did this routine on #1 and 6 for a couple of hours...then success 6 came free followed by 1. Time from IM off to #2-5 GPs out, 90 minutes. #1 and 6 another 3-4 hours. (well I did change the oil too so thats a plus).

I dremelled the element off one of the known bad GPs, drilled it out, mixed some JB weld and made a reamer with a shortened off 13/64ths old drill. Put it in a plant to hold it upright and called it a night. This morning, after a late start...friends plumbing issues, I reamed out the GP holes. #1 was incredibly fouled compared to the rest. I noted that 2-5 really didnt need reaming, nor 6, but 1 was caked especially at the element. 6 not so much, but the shaft definately.

Buttoned up with a cleaned out EGR, zipped the IM bolts in, final torqued IM 15 ft lbs-20nm, GPs 20 ft lbs-27nm, and good to go.

Pretty clear, which GPs were replaced by the dealer. I read that there is a difference between proper torque and proper seating. #6 GP was coked up the shaft, which maked me think it was either orginal(not likely) or not seated fully and soot was able to get around the element.

Pictures included I like pictures

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__________________
Treetops
06 E320 CDI 127K Miles
87 300TD 231K Miles

99 E300 269K Miles-Sold

I was really surprised at the amount of baked on soot that kept coming out of #1 GP hole. 2-5 barely had any and six wasnt terrible either.

Man...cleaning the EGR is not fun, messy and wow there is a lot of gunk. I used MAF cleaner as I had read warnings not to use brake cleaner. Some reports of messing up the EGR valve. If anything knowing its cleaner is something to me, overkill perhaps, but hey why not kinda point of the exercise.

I would not tackle this without the forum and those who went before me. Take your time, be patient with the GPs(probably the #1 reason others have broke them off) and no wonder why it costs a pretty penny to have a pro do it.

End of story

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__________________
Treetops
06 E320 CDI 127K Miles
87 300TD 231K Miles

99 E300 269K Miles-Sold

Great job! I've got to do this on my '95 with NA OM606, not looking forward to it at all.

So do you think the HF impact wrench reduces the odds of breaking a glow plug?

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Kroil is actually a bit better than PB.
Using anti seize on the replacements is a good idea too.

__________________
1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

Well, possibly yes because the 'real' torque value of the HF driver is unknown (very suspiciously low). I, naively, believed the driver was over powered for the job at 87 Ft lbs, but even at full tilt on a freshly charged battery it didnt do a thing. I think I tried the CCW then CW method for about 30 mins total(multiple attempts) and didnt get anywhere with the #1 GP using the driver. Results maybe different with a better/true to spec design...YMMV

Patient back and forthing with a good torque wrench set at 20ftlbs or so is what did it for me. (Its HF too so I suspect I may have gone over that) Also seems the Beru plugs shear at about 40nm or 29 ft lbs. The bosch ones I took out seemed to hold ok at 20.

I have not seen Kroil in my area at the usual advanced auto-zoo-napa, would like to try it tho. I was tempted to spray brake cleaner in there as well(maybe would have seeped past the threads to the baked on soot) but didnt.

__________________
Treetops
06 E320 CDI 127K Miles
87 300TD 231K Miles

99 E300 269K Miles-Sold

Penetrating-Lubricating Oils

How about direct from the maker ?

__________________
1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."