I found out that the original intake/exhaust manifold seal has a design issue that makes it more likely to leak than the new-style replacement. It has to do with the tendency for the bolts to get loose over time and then leakage can occur through the gasket "sandwich". I was leaking considerable oil blowby (mean for combustion) down the side of the engine out of the intake manifold. [ Blowby oil mist is routed to the intake manifold for combustion. ]

It is relatively easy to deal with the turbo drain seals if you pull the turbo. After that's out you can get the manifold gasket replaced too. These two gasket/seal systems plus the oil separator o-rings made for a much cleaner engine on the 1982 300D, and I plan to do the same on the 300SD later this year.

I also took off the lower oil pan, and while it was good to conduct an inspection and replace the gasket, if you perform the turbo removal then its not necessary to take off the oil pan. I took off the lower oil pan thinking that the lower drain tube section could be pushed downward out of the oil pan area - it can not be pushed in that direction, it has to go upwards.

There was no leakage whatsoever from the upper turbo drain tube -to- turbo gasket, and that was never unbolted in my case.

Don't use any RTV on a replacement turbo seal - there's too much motion and it will break loose and leak. Instead rely on the new grommet and o-ring down there.

Ken300D

__________________
--------------------------
1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles