'98 E300 TD with glow plugs stuck in head - Page 2 - PeachParts Mercedes-Benz Forum

milner351 · #16 02-20-2009, 11:29 AM

So far folks I've used every trick I know from 20 years of playing with all things mechanical.

I have not updated my thread recently because I have not made any more progress and have had to work on some other projects in the mean time.

I have drilled, re-drilled, tapped and re tapped the body of the glow plug still in the head.

I have used a slide hammer device I put together from threaded 3/8" rod - even used an air hammer against the slide hammer in both directions - and still nothing.

I have the 12x1.25 tap for the head threads now - and I've chased the head threads at least an inch down into the hole - I'm pretty confident now that all of the threads from the GP have been removed from the head itself....

However, it still won't budge, it is still sealed well - as I filled the hole with Kroil penetrant and it was still full the next evening when I came back to work on the car.

Last night after drilling deeper and tapping inside the GP further for the 3/8" rod, I heated the head around the hole with mapp gas and it still won't budge.

I'm about ready to put the rest of the things together to get the engine started (minus the intake manifold) and see if I can get it started and running with some type of "shrapnel shield" over this hole to see if the pressure of combustion and the heat of combustion will break this darned thing loose!

I'm pretty much out of any other ideas.... I'm most likely going to have to use one of Evans' threadserts if I drill any bigger - and drilling perfectly straight is not easy - the drill runs into the IP - a friend is letting me borrow his 90 degree drill this weekend - that may help with alignment.

KarTek · #17 02-20-2009, 11:31 AM

Put it back together and drive around until the GP blows out...

milner351 · #18 02-20-2009, 12:52 PM

that's what I'm thinking!

Matt L · #19 02-20-2009, 12:57 PM

Quote:

Originally Posted by JimmyL

Anybody know how much that tool is for the OM606? And does anybody around here have one? Is there one in the tool rental program?
Thankfully I don't need one at this time.

I kind of have a nagging question on this issue. Everybody keeps saying use an anti-seize product for the glow plug threads, but aren't these breaking below the threads or are they breaking somewhere at the threads?

I don't recall the exact price. $1600 comes to mind. I definitely remember that it was between one and two thousand dollars.

I very much doubt that there is one in the rental program. If I owned that tool, it would never leave my garage and another person's hands would never operate it.

aklim · #20 02-20-2009, 01:00 PM

I've seen one at an MB shop. Didn't even have the right inserts for our heads. I tried drilling it out but got the angle wrong and ended up almost making the head FUBAR. Fortunately we managed to drill a new seat so one plug sits lower than the other.

connerm · #21 02-20-2009, 01:36 PM

I changed 4 of 6 in my 95 last May. Two were really stuck. Tried the low torque impact driver on both for at least 30 minutes - nothing. Next time I'll try to remove them with the engine at operating temp or warmer AND I'll spray them down with freeze spray. I already have two cans of the coldest stuff that's easy to purchase. I figure I'll isolate the gp with a styrofoam cup and spray away. The freeze spray and some carbon cutter liquid may just be enough. Major design flaw in an otherwise good engine if you ask me. Seems the GP manufacturers could shave a little down when they make em.

I thought about machining off .002" or so from the barrel of the GP (Between the element and the threads. That's where it get stuck.

milner351 · #22 02-20-2009, 02:04 PM

now that sounds like a great idea!

i've lathered my new ones in antisieze for insurance - but making the OD slightly smaller on that barrel sure makes sense to me.

I should have left mine alone - now I'm stuck with weeks of wasted time in a so far unsuccessfull extraction - I'm just going to try to get it started and see if the pressure of combustion will blow out what is left!

Todd Miller · #23 02-20-2009, 02:33 PM

Okay, #5 has been extracted using the method described in the wikki here! I'll have photos later. Time to get going on #4.

nhdoc · #24 02-20-2009, 02:38 PM

Quote:

Originally Posted by Todd Miller

Okay, #5 has been extracted using the method described in the wikki here! I'll have photos later. Time to get going on #4.

Great news...sounds like it didn't give you too much trouble if you have it out already!

milner351 · #25 02-20-2009, 02:51 PM

WOW - you're making me feel like a real dumby here - that's great progress - I'm beginning to think my #4 is held into that head by satan himself!

Yes - please show pictures!

Todd Miller · #26 02-20-2009, 02:59 PM

It was very straight forward. I think I spent maybe an hour total of actual work time. Took longer than that of course, but to just stand there and do it, it goes fairly fast.

#4 will be harder because it didn't unscrew at all. It simply broke. At least with #5, it had already unthreaded about 3/4th of the way.

I will post a bunch of macro photos, but probably not until this evening.

milner351 · #27 02-20-2009, 03:03 PM

Nicely done - yea - your #4 sounds more like mine - it didn't realy move much at all.... sheared in the threaded portion of the plug... and the plugs I took out were bosch... not autolites.

The only other thing I can think of is that this plug is actually bent in the heating element area - or enlarged in the heating element area - and therefore "seized" so tenaciously into the head.

Nice work! I certainly hope you have better luck than I have!

Todd Miller · #28 02-20-2009, 08:40 PM

No good news to report. #4 is being a real b!tch.

I didn't realize it, but the glow plugs are actually angled slightly forward in the head. I must have gotten lucky with #5 (I wondered why the drill seemed like it was drilling crooked when I'd stop and look inside the hole).

So, this is starting to get ugly....again. More updates later.