I have been lurking here a while and finally decided to be a member as there is so many good conversations going on here. I recently purchased two months ago a one owner 1995 E300 that I have been trying to buy for 3 years. Long story but he finally sold it to me and I have been having a blast going through it mechanically to learn it and start to list what items I want to replace for longevity and reliability. It runs great but it does have a little lumpy idle, not bad but not glass smooth. I can see one of the crankcase breather hoses that attach to the intake has a small crack in the rubber but I am really thinking it is a injector/nozzle. I get a haze of smoke at night in a following car when I give it a little throttle but during the day no noticeable smoke. At idle and the engine is cold or not super hot it has a secondary occasional "rattle" that goes away when fully warm or if slight throttle is applied.

The owner has meticulous (every receipt and fuel fill up since new) records and I went through them and in the 288k miles it has on it there is no significant injector pump or injector work done. It has had glow plugs 4 times (all 6) and the return fuel hoses have been done about 3 times but that is the extent of the fuel delivery system work. Should I consider the nozzles for replacement? I really want to get that idle as smooth as I can get it. When the AC is on and it is idling when the compressor kicks in or out it has a fairly good "bump" on the idle as well.

I am going to replace the vac pump as well as a preventative, I have already replaced the shock tensioner, tensioner arm, belt, idler and all fluids including the rear end oil. I have a really slight weep of coolant on the passenger rear side of the head, once it warms up it does not weep. In looking at a head gasket I think it is the o-ring in that back corner. So the head will need to come off at some point as well. No oil in coolant or coolant in oil.

Fun car to tinker on and I have two other new MB diesels that I only do maintenance on but something in this I-6 engine speaks to me. Its a blast to cruise around in.

thanks for any suggestions,