On my way to work today, the 300D ('92 2.5T) started faintly knocking. Over the course of the next couple of blocks, and into the parking lot at work, it was knocking loudly and smoking like crazy. Power seemed to be fine, and the knocking decreased a bit as the car coasted into the lot. Under power, the knocking was more pronounced.
I checked the oil, which seems to be OK, and the smoke seemed to be a lighter gray. Didn't smell at all like a head gasket failure; it was burning oil or fuel, I think. Hard for me to tell the difference as it was quite cold and windy this morning. I went back out later and re-strated the car while the engine was still warm. Still knocking and smoking like crazy. Oil pressure looks good.
I am going to try to limp her home at lunchtime (and fumigate the neighborhood) and try cracking injector lines to see if I can hear/see a difference. I have a short lunch, so that's all I'll have time to do. I am also heading out this week for a 5+ week military deployment, so diagnosis time will be virtually nil with the holidays and all. I need to spend time with the wife and family before I head off and miss Christmas and New Years, obviously.
Anyway, any other thoughts on relatively simple diagnosis procedures or things to make note of, in particular? I am hoping GSXR's suggestion (via PM) that it *could* be a stuck injector might be right. Boy, that would make me happy. I had planned to send them all off to CSeanWatts when I got back anyway as there has been a slight miss at cold idle once in a while (with accompanying little puffs of white smoke) and nailing.
Any thoughts/suggestions/prayers would be appreciated!