lubricant on stuck glow plugs?
 

Hi all! Discovered that on my '82 300SD the oil plug is mostly stripped and unmovable and I will have to take it into a mechanic for replacement.

I am preparing to replace the glow plugs and upgrade the replay to the post glow. If I run into unmovable glow plugs can I use a lubricant to get them to loosen?

Thanks!

Buy a new pan, gasket, and plug. Take a drill to the pan you have now (carefully) to drain it if you have to. I have to think you'll still come out ahead money-wise.

I suppose you can try some PB Blaster for the threads, but the problem is usually a ballooned/carbon encrusted glow element. For that you just be carefull and keep turning it while pulling it out.

I put a tiny bit of LM anti-seize on the threads before installation of the new ones. Some say to use "special" lube, but this has worked for me. Just don't use gobs of it and you'll be fine.

It's pretty rare I think for a glow plug to stick/break on the older diesels like yours. It's the 210 chassis that has the problem.

If I am reading this correctly, your drain plug has it's hex flats rounded off so your wrench can't get a good bite on it. Try using vise grips on it and tapping them with a hammer until the bolt moves. You might even want to heat the pan area around the stuck bolt with a propane torch for 40 to 60 seconds and then try the vice grips. If that fails, try drilling the drain plug dead center and use a large easy out.

I haven't had much luck with soaking the glow plug with penetrant but I have had good results with heating the area around the glow plug with an oxygen acetylene torch for 30 or 40 seconds and using a six flat closed end wrench to get to get them loose. Once clear of the threads a pair of pliers twisting on the glow plug will clear the carbon off.

Vice grips might work but also might make things worse. Try a set of those EZ-Outs you can get at sears for 20 bucks. They are amazing for rounded off bolts and such.

You won't have any problems removing the glow plugs from a 617 engine.

Thanks for all the help guys!

I purchased some PB Blaster and hit the drain plug and glow plugs with it. Thought I would let it soak a bit and then change the glow plugs out.

With all the GP horror stories on the board, I wanted to take some kind of initial action before digging into them.

If the oil drain plug is stripped it's time for a new one. Find a new one then use a pair of vise grips on the old one to get it out. I just did this on one that came into the shop. The plug was almost round. A new plug is cheap.

Most of the real horror stories related to glow plugs are on the newer engines like the 606 with aluminum blocks and long, thin threaded shanks on the plugs that tend to break off due to dissimilar metal, corrosion or something. Then the head has to come off ... well you probably already read the stories. Like Brian said, don't worry about the 617. Use Beru or Bosch plugs.

You may want to have a long "grabber" tool handy to pick up the small nuts that affix the wire to the center posts, better yet a new nut or two just in case you lose one. They tend to fall down and disappear behind the IP.
I got to use a coathanger wire once to retrieve one. Small things like that can lead to a bad experience but you don't usually repeat the same thing again.

Perfect application for my favorite tool, a giant pair of channel locks. the combination of aggressive teeth and a long handle will cause the stripped/stuck drain plug to surrender faster than the italian army.

No heating, no drilling. Total job will take about 2 seconds.