Yes, I checked the clearance in the right area. And what I meant by broke, was when I put in that glow plug, the upper part unbolted and a bunch of white powder fell out. I wasnt sure what that was, so I installed an old one, but I thought maybe it was the one that was failing, so I changed it out with a could of more, but it still starts the same. I have a feeling that glowplugs are definatly a problem, but its not the problem of the white smoke and misfire randomly. The white smoke doesnt stop, no matter how long the car is running. I have a 300SD with the 617 and it starts up rough because of glowplugs, but one it warms up, it runs really smooth and doesnt misfire. Here is a video of the startup. 300d w123 rough start - YouTube