A couple of my glow plugs failed on my 1999 E300D Turbo just after 114,000 miles. Ironically this occurred about 3 weeks after I had to remove the intake manifold to replace the leaking delivery valve o-rings that had been leaking for some time. The threads on this website were very helpful and the o-ring replacement went off without a hitch. The glow plugs were another story. It’s new years day. I ordered the parts from Rusty Cullins at BUYMBPARTS.com a great place to get any part you need. I started off at 7:30 in the morning thinking this would be a 2 hour job at most considering that the most difficult part was gaining access by removing the intake manifold which I already had experience from just a few weeks prior. I had done my web research and found a very helpful article at http://www.mercedesshop.com/Wikka/OM606962GlowPlug Well the manifold came off in under 20 minutes because I already knew exactly what was needed. I attacked the #1 glow plug and just as warned I was cautious about applying too much pressure. I used about a half of a can of PB blaster penetrating oil just as a precaution. Starting with a 3/8” ratchet and a 12mm deep socket I attempted to remove the first plug. Applying about as much force as I could the plug wouldn’t budge. More pressure got it to budge making a sound like a creaking hinge on a stuck door. It was like snap snap. I worked it back and forth applying more oil and waiting a few minutes between tries. Finally after creaking all the way out the first plug came out. Even after the threads were clear I had to work it the rest of the way out by applying pressure sideways on the socket to pull it from the head. On to plug #2. I applied a little more force by using a 3/8 to ½ socket adapter. This was a mistake. Creak creak and then it seemed to be free. What happened was the plug snapped off below the hex and just above the threads. The core stayed attached so there was a little friction making me think that the plug was coming out at first but I was mistaken. Discouraged and realizing this was going to turn out to be more than a one hour job I moved on to #3. This plug came out as easy as a regular spark plug. Not to belabor the story #4 and #5 suffered the same fate as #2. For #6 decided that I couldn’t take a chance of loosing this one because the access was blocked by the oil filter canister and drilling would require some serious disassembly. I went back to the 3/8 ratchet and creak creak it came out just like #1. The broken #4 plug had the best access so I tried to do an extraction process on that one first. I took one of the old plugs and sawed off the hex section about where the plug snapped so I could gain some insight as to what the internal construction was. Turns out that the construction is a shell about 1/8” thick with the electrical core running through it. So I snapped off the broken section by working it back and forth with a pair of pliers and then used a 5mm drill to drill out the core leaving the shell intact. I then inserted a spiral type ez-out and tried to remove the plug. This didn’t’ work. Next I drilled using a 3/8 drill deep enough to clear the threaded section without drilling wide enough to damage the threads in the head and then drilled the 5mm hole deeper into the plug to sink the ez-out below the threaded section thinking that the extractor was expanding the threaded section and applying too much compression on the threads.. All the time I was spraying penetrating oil every time I got a chance. After breaking one socket and one extension bar and one tap wrench I realized this wasn’t going to work. Back to the web to discover that this is well documented problem to the extent that Mercedes has come out with a special extraction tool kit which goes for the tune of $1300 dollars. I stopped at this point blistered hands and broken tools and packed up the parts until the next morning when I called my local dealer. I explained exactly what I had done. He said it’s quite common and it happens to them all the time. I asked him what the worst case cost would be. He put me on hold for a few minutes and came back and said it would be about $1300 if they had to remove and replace the head. The web articles I read said this only was necessary in about 2% of cases since they came out with the special tool. I had the car towed to the dealer and after a day and a half I got it back washed vacuumed and with a bottle of dealer branded water in the front seat along with a bill for $2401.81.
Lesson learned…if you hear a creaking sound stop, put the manifold back on and have the dealer replace the plugs. If they break them off you’ll only have to pay the book rate.

 

Have not been working on the glow plugs but they say the CDIs are tough compared to the older engines. Referring to your write-up, I wonder what that could mean.

 

The plugs on the 99 are more than twice the length of the ones on the 87 I had. Probably because the 4 valve head is almost twice as wide as the older 2 valve styles. All that area for any blow-by from the seat is a recipe for disaster.
Here is a shot of the 87 plugs
http://catalog.worldpac.com/buymb/02...part=Glow+Plug
and here is a shot of the 99 plugs
http://img.eautopartscatalog.com/live/F110062530BOS.JPG
I couldn't find a picture of the CDI plugs but I'm guessing you are correct same potential problem

 

Wow, what a story. I replaced the 5 glow plugs in my 92 300D (602) last year and found the plugs not difficult to remove, similar to the older 616/617 engines. I'm saddened to read the newer models have such an expensive remedy to a simple repair. Makes me want to make my 123s and 124s last a long time.

 

i just got my 99 turbodiesel back from the shop and my guy told me that he wasn't able to get 4 of the plugs loose. I guess that he did the right thing by not trying to force them. I've had the car since new and it just passed 245,000 miles so i don't want to put much more money in it. Does anyone know what the dealer will charge to remove the plugs?

 

Surely MB and other car makers have thought about such a problem. Is changing the glow plugs similar in degree of difficulty to that of replacing the spark plugs in gasoline engines? Yet I have never heard of someone unable to remove a spark plug.

Comments?

 

http://www.youtube.com/watch?v=koghDoROFko

about how to remove a seized glow plug.

 

Does any one know the name of the $1200 part Mercedez makes for its dealers to remove 1999 glow plugs?

 

The video posted previously is for the CDI engine, not a 606.962. The prinicpals are the same but the 606 does not have the neat milled out areas surrounding the GP to allow sleeves/guides to be used.

This procedure works for most. http://alan.mcreynolds.googlepages.c...-mercedesom606

Its important to install a 3-4" stud in each adjacent GP hole so that you have some sort of reference of the angle needed prior to attacking with the drill.

If the hole does get buggered a time-zert insert seems to be much cleaner that helicoils.

I've got the extraction kit part number somewhere if you really need it; in addition to other sucessful extraction links.

 

Wow...Thanks so much. The dealer called yesterday and said they couldn't get the glow plug out and it was going to cost $4500 to fix it.
Now I find out that this is apparently a pretty common problem with this model so I brought that to the attention of the dealer. They were apparently unaware that there might be some better solutions than their ideas and agreed that we would all look for some better ideas.

I read on this forum that there was some part that MBZ actually designed to solve the problem so I am looking for that as well as any other reasonably prudent ideas. I am hoping to get back to them on Monday and compare notes. They are very open to any ideas that I can share with them so I will give them that. I guess the dealers just don't see that many of these cars and apparently MBZ doesn't have a very good system in place to keep them informed.

Any suggestions you have or references you have to potential places to get this fixed are appreciated. I see you are in the Bay Area and we live just north of San Francisco so I can get to just about anywhere in the Bay area to Sacramento in order to make sure this gets taken care of properly.

 

Here the GP extraction kit and part number. Note the WIS doc number too; you dealer should read it and "brush" up. http://www.startekinfo.de/etools/con...2002%2099%2000

Which GP is the problem. Is it broken, or just not comming out? $4500 sounds like the I'm gonna give up before i even try and pull the head and send it to the machine shop method......

I know of no dealer in the Bay Area I would use which is why I do my own maint etc. If I were forced to use a dealer it would be one who had a mech who was conversant on the 606. It sounds like your isnt if they didn't know the tools even existed.....

Failure analysis (breaking point) of Beru GP's (OEM). See post 17. http://www.peachparts.com/shopforum/...ow+plug&page=2

Extractions -
Post 31 http://www.peachparts.com/shopforum/...=broken&page=3
http://www.peachparts.com/Wikka/OM606BrokenGlowPlug

 

Thanks so much for your assistance. I really appreciate it.
Cynthia