Fintail Eats Glowplugs

[Furious D]

Well, the title pretty much says it all. It's an OM 621 that was poorly maintained and burns a A LOT of oil right now. It also has a tendancy to "knock" or "nail" lightly under part throttle acceleration. The car was last driven in '92, so I'm expecting little things like this. It's chewed up four glow plugs within 200 miles of driving. Is this something to be concerned with? Or is it that I'm just dealing with old junk, and should get some new plugs? The car came with a boat load of spares, so I've just been throwing those in, rather than ruining new ones if that isn't the problem. The car already runs/drives a million times better with the limited mileage I've put on it, but if something is seriously wrong I would rather not do any more dammage by driving it. The plugs go in looking like the one in the background, and come out looking a little less healthy. I don't think it's the glowing procedure thats killing them either. The car glows fine and starts after a little encouragement. It's after you shut it down and attempt to glow it the next day that nothing happens. This is what makes me think that it's a poor running condition thats killing them. Here's a picture of the carnage.

Have you thought about upgrading to the pencil type?

[JimmyL]

You might need to remove the glow plugs and ream out the holes (more action than I've had in months..... ) Sometimes a carbon buildup can cause problems with the glow plugs.
Or, they might not have been that great to start with.
I second the idea of converting to the pencil type. Folkes swear by it!!!!

[Rahulio1989300E]

Originally Posted by JimmyL

You might need to remove the glow plugs and ream out the holes (more action than I've had in months..... )

BWHWHAHAHAHAHAHAHHAHAHAHHAHAAHH!!!!!!!!!!!!!!!!! LMAO!!!! ROFL!!!!!!!!!!

That's a nice looking fintail, congrats on getting it back on the road.


I once had a 1964 190Dc that had sat for years before I bought it, and it did the same thing. I can't tell you why, but I can tell you that when I upgraded to the fast glow plugs(pencil) the car started much better and faster. Not to mention, it quit burning up the plugs. Plus, one bad pencil glow plug will still allow the other three to work, unlike the loop plugs.

Mine smiked like crazy, until I adjusted the valves and brought the compression back up a little.

Try putting a can of Sea Foam in the diesel fuel. The farmers around here swear by it.

[KCM]

Concerning the glow plugs, check and make sure that the resistor on the firewall under the hood has not been bypassed. This will eat up glow plugs in a hurry. Also check to make sure the guard over the resistor is not loose and shorting across the coils of the resistor. The glow plugs should last many years without burning out.

These engine can nail pretty good, especially when cold. You might try retarding the timing just a little, but no so much that it misses on acceleration. NEVER adjust the timing with the engine running as you would a gas engine, as this can cause the pump to self-destruct.

For maintanence, adjusting the valves is alway a good thing to help starting. Don't forget to check the oil level in the injection pump, and fill to the check plug if necessary with engine oil. And make sure all the front suspension pivot points are well grease, as they use threads for pivoting and can lock up if not greased well.

[Furious D]

Thanks for all the help. The car is really a hoot to drive around. It's slow, stinky, and noisy, but that's all part of the fun. I've done most of the maintence stuff that everyone had suggested, but I'm going to double check the valves and fluid levels and re-grease everything now that it's been driven. Does anyone have a part number for the pencil glow plugs? They sound like a nice upgrade. Now I've just gotta track down a couple of oil leaks and she'll be good to go!

I think the pencil plugs come in a kit, with new cables to connect the plugs together. It eliminates the toatster wires and porcelin insulators. The kit is sold as a fast glow kit. Any Bosch service center should be able to get it for you.

[JimmyL]

Originally Posted by Furious D

Does anyone have a part number for the pencil glow plugs? They sound like a nice upgrade.

This should work....

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1VK01GHCF1WH02II22&year=1969&make=MB&model=220-D-001&category=F&part=Glow+Plug+Kit


other sites have them too. That is a very low price. Hope it's the right one.....

[rsd]

yes ,I do have exactly the same 200D fintail with the same problems. My engine did eat up 2 glow plugs in 6K miles, a lot of smoke on start up, poor start ..but once started runs very well (for its 55 hp )... so I've found a set of 4 fast glow plugs on ebay for $47 and I am going to install them , just one thing , plugs are rated as 9V DC ?? does this mean that firewall resistor still needed and plugs need to be connected to it ?
I've seen this kit on ebay , somebody mentioned before, pic of that kit shows 4 plugs and some electric wires .. I did not see any time relay ?? .. any comments on what is the proper way to wire these fast glow plugs ?
Thanks.

The plugs are fed power the same way the old one's were, BUT the important difference is that the ground wire at #4 plug is no longer used. The new plugs are self grounding. Hope this helps.