I have a question for you engine people out there. On my '95 S350 - 262,000 miles, the car runs rough (real rough) after starting for about a minute and produces a bluish-grey smoke out the exhaust. It just started doing this. Then it runs smoother and no smoke. I did a compression test - twice - and here are the average results of both tests.
1- 458 psi
2- 420
3- 478
4- 465
5- 448
6- 465
The book call for normal compression between 377-464 psi with a minimum of 261 psi. Maximum permissible difference between individual cylinders should not exceed 44 psi. The #2 cylinder is 55-60 psi below #3. Could this make the car run rough at idle? Could oil be seeping in #2 while the car is not running and then it has to burn it off when it is cranked? I installed new injectors when I did the compression test and can tell no difference at all - performance or smoothness. All the glow plugs are working fine and I replaced the glow plug controller. The engine has never been into at all. It uses about a quart of oil every 1500 miles. The dealer mechanic says if it was his, he would just run it. Seems like it is getting worse though.
What do y'all think?

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1995 S-350
370K + SOLD
1952 220B Cabriolet
39K kilometers + SOLD
1998 E300D
310K +
2012 E350 BlueTec
120K