Hi guys,
I just drove my '81 300SD w/ 245k miles up to Flagstaff from Phoenix yesterday, and within a few hours of having parked it in the garage, there was oil spots on the floor correlating to the path of the tail pipe, pretty much all the way back. Where could that be coming from being an external leak and not from within the pipe itself? Other than that, the car did very well up the mountain passes, easily able to maintain speed with little to no smoke, which is a nice change from the '76 240D I had a while back. - Mike

Only way to tell is to get out and get under.

https://en.wikipedia.org/wiki/He'd_Have_to_Get_Under_%E2%80%93_Get_Out_and_Get_Under_%28to_Fix_Up_His_Automobile%29

https://en.wikipedia.org/wiki/Get_Out_and_Get_Under

Get Out and Get Under (1920) - IMDb

The Cover Gasket is a typical place and the Oil often goes towards the rear and down the bell housing.

The Turbo Darin Oil Seal is a common leak area.

The front and rear Crankshaft seals.

There is the seals between the Torque Converter and the Input Shaft and the Rear Cranshaft Seal will leak out of the same hole at the bottom of the Bell Housing.

There is the Transmission Tube Dipstick Seal.

Rear Transmission seal?

I have not read of someones Oil Filter Housing to Block Gasket leaking a lot but if there was somthing wrong with the Oil Filter Housing Lid Gasket that leaks a lot as do Oil Cooler Hoses.

The problem is that sometimes you need to clean off everthing in order to pin point the exact leak area unless the leak is large. I had that issue when first got the Car. I thought I had a rear Cranksaft Seal Leak but it turned out to be the Valve Cover Gasket.

__________________
84 300D, 82 Volvo 244Gl Diesel

Is your engine oil level down ?
I assume yes, so at what rate ... miles per unit of oil ?

Really the first step is to clean the engine compartment and under the car as best you can..
take short test drives and examine it ... so you catch the leak just as it starts to show...

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html