Glow Plug Hater - PeachParts Mercedes-Benz Forum

longshore1 · #1 08-18-2006, 04:10 PM

Eight months ago I tried to replace all my glow plugs in 1995 E300D, one of them broke and I tried to drill it out, WHAT a mistake and it cost me a new head and a ton money. So I went to replace one that burned out and it broke again. these plugs have been in for 20,000 miles and I put anti seize on the threads so they would easier to remove in the future. Now its back to mechanic so hopefully he can pull it out or have it sent to a machine shop. I am I retarted or what.

I soaked it in screw loose, loosened it, tighened it and it was coming out fine then SNAP!!

How does everyone else replace these things without them breaking? I could have bought a newer car since I bought the thing twice already. Is it these engines or what. I used Mercedes plugs since the one that broke last time was a bosch.

just thought I would ask since the simple act of replacing a glow plug has cost me a lot of money and frustration. Iam going to mix a stiff drink and try to forget till monday when it goes to the shop.

activ123 · #2 08-23-2006, 01:28 AM

Am in the middle of your saga now with my 99e300td. After wringing the nut loose on a GP I decided that I'd just let the dealer fix it. Then I found out their worst case price. $1000 if I'm lucky, another $2400+ if I'm not. Gievn that price, it seems only reasonable to give it a shot.

The plan is to put loosening oil on the GPs everyday twice a day for a full week and then try and loosen them. Since I wrung the "nut" loose, drilling should be relatively (famous last words) safe since I only need 1/2 inch for an easy out to get a grip and I'm up near the head of the GP (as opposed to way down inside the head). I won't try drilling the broken one out until all the others come out fairly easily (after continuous bathing in oil) If two weeks goes by and nothing budges, then I figure fate will have decided my course of action and I'll button it all back up and drive it to the dealer and cross my fingers...

One thing I seemed to discover in my quest for information on this problem - the previous GPs (in years gone by) were much better design - short, squat, and fat - no breaking problems there. Wonder what the engineers were thinking on these...

Andy

sokoloff · #3 08-23-2006, 08:22 AM

Lots of good stories/opinions/successes/failures - do a search for "broken glow plug" to read them.

Here's mine - http://www.peachparts.com/shopforum/showthread.php?t=109101&highlight=broken+glow+plug

Len

aklim · #4 08-23-2006, 08:56 AM

Not a gaurantee but I think you are fine. I had the same issue and had drilled it wrong so the machine shop had to fix my "oopsie". Fast Forward to 1.5 years later and it came out just fine.

TheDon · #5 08-23-2006, 09:01 AM

thats the only issue im not going to buy an E300D, the glow plug issue, and MBZ knows about it, i think they even make a tool or kit for when that happens, my neighbors father in law was almost shafted by the local MB dealership because when they changed the glow plugs on his sprinter one plug broke, they tried to charge him for a new head, he called customer service and got in contact with some one up in the chain and he only had to pay for the glow plug job and not a new head

aklim · #6 08-23-2006, 09:08 AM

Quote:

Originally Posted by TheDon

thats the only issue im not going to buy an E300D, the glow plug issue, and MBZ knows about it, i think they even make a tool or kit for when that happens, my neighbors father in law was almost shafted by the local MB dealership because when they changed the glow plugs on his sprinter one plug broke, they tried to charge him for a new head, he called customer service and got in contact with some one up in the chain and he only had to pay for the glow plug job and not a new head

Yes and no. They have a tool kit for the plug problem but it didn't work. Nothing in it would be able to make it work and I had to master MB techs look at it and couldn't figure out how to work it.,

#7 08-23-2006, 09:09 AM

You don't want to buy that tool kit though. It is heart-stoppingly expensive.

aklim · #8 08-23-2006, 10:07 AM

Quote:

Originally Posted by mrhills0146

You don't want to buy that tool kit though. It is heart-stoppingly expensive.

It didn't ahve the inserts for the 210 for whatever reason. We checked the parts list and none of the helicoils would fit.

longshore1 · #9 08-23-2006, 02:48 PM

well the head is coming off and going to be sent to a machine shop. well see what happens. be careful drilling one out the drill must be at the proper angle or you go into the head

1983/300CD · #10 08-23-2006, 04:30 PM

Make sure you ream the GP hole every time. That should stop carbon from gripping it if the tip baloons.

aklim · #11 08-23-2006, 10:19 PM

Quote:

Originally Posted by 1983/300CD

Make sure you ream the GP hole every time. That should stop carbon from gripping it if the tip baloons.

I never had that happen. Even after 55K and a stuck plug, we took it to the machine shop and they said the prechambers were clean.

activ123 · #12 08-30-2006, 02:15 PM

e300td.

The glow plugs has been soaked in Liquid Wrench for four days - three have come out with little problems. One is pretty much stuck although it does turn back and forth. I figure I'll switch to Marvel Mystery oil tonight. I have two wrungoff heads now though. These things are not on a 90 degree angle to the head so I'm wondering if the angle changes from cyl to cyl.

Does anyone have a diagram or specific knowledge about the angle of the GP ports on the 606 head? They all seem to be angled slightly towards the rear of the motor, but are they all at the same angle? It's hard to tell. Since I have to drill twice (thereby doubling my chances of messing up!) I figured I'd ask...

thx

Andy

dieseldiehard · #13 08-30-2006, 04:12 PM

There is a machine shop here that has successfully removed stuck GPs from the 606 heads, the dealer sends them there occasionally.
The fellow showed me how he gets them out. He sets the head in a flat bed then mills them out using progressively larger boring tools (not with a hand operated tool!) then when he finally gets close to the aluminum thread he stops tha process and then uses a tap to push the remaining GP material that is in the threads out. Its a very slow process. But you don't wind up buying a new head.
As I said elsewhere, if I owned on of these engines I would be replacing GP's every 18 months.
And I would use some Alunox on the threads of new plugs when I installed them.

connerm · #14 08-30-2006, 04:55 PM

1995 e300d 171,000.

It is my understanding that the primary issue at hand is that carbon accumulates on the tip of the gp which keeps it from sliding out of the prechamber. Breaking the threaded part might be the result of trying to remove the stuck gp tip. Still sucks.

Motorhead · #15 08-30-2006, 05:01 PM

One trick I learned in my VW aircooled days was when a spark plug was stuck, we went out and drove the car, got it hot and the plug usually removed easier. I think the soaking is a good idea.
Get the engine hot (operating temp). Get your tools ready. Just before you are ready to loosen the glow plug, COLD quench it with penetrant, WD40, or best yet, buy a can of the aerosol "AIR" spray that you use to blow computer key boards clean. Turn the can upside down and it will spray VERY cold liquid. This will locally "shrink" the glow plug metal while the head is still hot and expanded. This little bit may be enough to get it out. Don't over torque the new ones.