Glow plug removal aid.

Mercedes switched over to the Bosch pencil style glow plugs starting with the 601 motor in 1987 and used all the way until the latest inline diesel Sprinter. These glow plugs are a cylinder head engineers dream with their long and slender compact design but an absolute nightmare to the repair shop tasked with having to replace them. These glow plugs have been known to seize and break upon removal and there are four main reasons this happens all resulting in a very expensive repair bill (Bearing Service in portland charges 300 per broken plug after pulling the head and it being on the bench).

The four reasons the glow plugs will seize and break off in the head have been narrowed down to the threads seizing from corrosion, this will break the glow off without ever turning when attempting to loosen. The long shaft being impacted with carbon, usually resulting in getting 1 to 3 turns before it starts to bind up, creak and groan. The tip being coated in carbon usually is in the 3 to 5 turn range before it binds up, less creaking and groaning with this do to the surface area. Then the last reason for seizing is the tip of the glow plug overheating and being egg shaped, when this happens you are stuck either with most of the threads out or completely out.

The goal of the service is to reduce the chance of breakage where the carbon is to blame. The diesel care and 244 ran through prior to service will usually remove or at least soften the carbon you would be fighting. I personally have been involved in multiple services doing it this way and there has not been one that couldn't be removed(some needed a bit of love'n to get it but no machine shop work).

BG technical