Hi all,
I just bought a 1993 300D 2.5t, absolutely amazing car to me who only knew pre-1987s. 155K miles. Incredible acceleration. Smooth as silk. Tight steering, agile, yet like a tank at 80 mph on the highway. The weird thing about it is the following: it starts up super easy, even at 5 degrees after three days of not starting it, gp cycle runs once, starts up without any hesitation, you don't even have to touch the accelerator. It will then run totally smooth, no skipping, no smoking, for about 2 minutes. After 2 minutes, it will begin to run rough, not really rough, but skip every once in a while, and start blowing smoke. More than anything, the valves are quite clattery and loud, much louder than my 617s. Smoke not really heavy, but more than it should I think. It'll keep doing that until it's warm and I drive it, will belch a few clouds with the first accelerations, and then not smoke at all when driving, even under heavy acceleration. When you leave it idling for a while, it will start smoking again ever so faintly. Somebody suggested to me that it might have been overfilled with engine oil, and indeed it had. He said that with these models, the oil level has to be just under the max mark on the dip stick, and it was slightly above. I sucked out about 1 quart with the mightyvac to get it to be just under the max mark. And that improved the valve clatter somewhat, but hasn't stopped smoking yet (but I haven't driven it a whole lot since then). There are two other things that seem to be going on: There is a slight oil leak at the IP at the shut off valve. Additionally it just stopped shutting off with the ignition and you have to press the stop thingy. The vacuum line to the IP is not ripped off or anything. Do you think that this may have something to do with the smoke/valve clatter/skipping? Why does it stop the bad stuff when it's warm and it's an issue only when idling? Any ideas? Suggestions? There is no gunk in the water, so I don't think head/headgasket should be the problem. And because of the excellent cold starts and acceleration, I don't think compression should be the problem either.
Christian

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1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50