I have a 1982 300sd. I recently replaced all 5 of the glow plugs when I found 2 had gone bad. About a week later 3 of the new ones went bad.

I did not ream out the prechambers when I replaced the glow plugs. Could excess carbine have damaged the new plugs?

I tested the relay and it seems to be working right. It cycles off after about 20 seconds. All of the connections seem to be good.

Is there a good way to ream out the prechambers without buying the special reaming tool?

Thanks for the help. Jim

Yes, excess carbon can cause damage.

You probably could find some other method, but I have found that using the mercedes special tools is often the easiest way of doing the job.

I have cringed at some of the tool prices, but when doing it yourself, you are saving a fortune in mechanic's charges anyway.

HTH,

Neil

Does importpartsonline have the reamer to remove the glow plug carbon? I searched under tools and did not see it. And do I have the same prechambers in my 1986 300 SDL? I will be replacing the glowplugs this winter and I would like to do the job correctly. Thanks for your help.

Your engine is different, so the prechambers probably are as well. Oddly, I don't think I have heard of this problem in the OM603 engines. While the tool for jimhammond's om617 engine is readily available, I am not having any luck finding a similar tool for the 603 either. There may be a good reason for this...