I just went thru the same thing about 2 months ago. I went to the cummins dealer up the road and it is hard to figure out which plug you need by the drawing they have. We just happened to guess the right one. I screwed the first one up by knocking it in there crooked, and when i tried to square it up with a small punch, i stretched it out and put another hole in it and it still was seeping.

So i went back and ordered 5 of them. This time I took the turbo and exhaust manifold off and it made it much easier to access, so that is what i recommend because I took the turbo/manifold off as one piece and it really didnt create much more work considering I was already doing it for the second time anyways.

Part # from cummins is 3945093. I would suggest you buy a couple of them because they were only $0.60 each and the shipping was like $4.00. A small socket works to drive it in and with the manifold off it gives you a little more room to swing a hammer.

 

Thats great, thanks very much for that. Tomoro off to cummins I a go...

 

Did you pull the old one out? Or put the new one in over it?