JamesE.

'06 320cdi glow plug light would stay on for 30-60 seconds after ignition. This went on for a week or so before the check engine light came on.

Took it into a local indie who said he couldn't get the plugs loose so we took it to local dealership and they're saying the same thing. They say one of the plugs is broken and the others are stuck and the only way to get them out is to remove the head and have them drilled out. To the tune of about $6,000.

The vehicle was a CPO purchased at said dealership and has just over 100K on it so the extended warranty is expired. Our service advisor has suggested we contact MBUSA regarding this to see if they might help, but I wanted to check around and see if anyone else has experienced this issue.

mtrevelino

Start looking here:
https://mbworld.org/forums/search.php?searchid=12602542
The MB dealership should know how to remove a broken glow plug with the MB tool. Since he is not familiar with that, I would hesitate to have them work on my vehicle.
Mike T.

boardboy330

I guess the main question is...how did the one get broken?

Old trick is to run the vehicle to temp and then try removing the plugs (this was a flat head V8 trick for head studs). I just did this very thing last week and mine spun out. They squealed ALOT...but they all came out clean.

rediesel

I had one plug go bad a few years ago. I drove it 9+ months thru a very cold winter (parked outside) without a problem. You probably need 6V Beru plugs (I did for my 2006). Find out which plug # is bad; mine was #6 all the way back. I only replaced the bad one. I also got a special boot removal tool (pliers) but they weren't necessary. I definately removed the plug after I got the engine good and hot (wish I removed the plastic before). It isn't any more difficult than replacing a spark plug. They can break off but you can usually tell because they spin easily while not coming out or are in two peices (they rarely break off inside). As long as you don't torque off-axis you should be able to get them out (you don't want to break it). I put anit-seize on the new plug and reinstalled it making sure to torque it to spec. Autozone cleared my code and it has been fine since.

Plutoe

That's not totally true, removing the heads and drill out, there are loads of good German glow plug removal tools(suppliers to MB dealers) available in the USA(about 600 bucks) to do the job quite nicely without taking the heads off.

Your issue is finding a greaser that has a set and knows how to use them.

Search the web-- contact the tool makers and ask for someone in your area that may have a set. I would also check with good repeat good diesel truck repair centers