I have a 79 300SD with the I5 diesel. I recently had some issues,as evident in a previous post, with the lack of pick up from a dead stop. I cleaned both ends of the line from the ALDA and the banjo bolts and, sure enough, it was clogged. After cleaning I noticed a mild improvement but still a lot lag. I took it out on a local highway and put it through its paces in an attemp to clean it out. When I checked under the hood when I returned to the shop, I noticed alot of oil blowby had come out of the valve cover by the PVC valve as well as the oil fill cap. From the looks of the surrounding areas, this is not a new issue. There is a considerable amount of caked oil residue on the block and surrounding areas. Could this be a problem with the rings? Is there a lack of compression thats making the car lag w/o the turbo? I would expect a engine with a compression problem to have trrouble starting but this one cranks right up. With this being said, I am used to gasoline engines. Any help or suggestions as to the diagnosis and repair of this problem would be greatly appreciated.