S Class 2.8 engine oil leak

My 2.8 appears to have an oil leak, it only looses oil when the engine is running and a little after it has just stopped. No oil is dropped once left turned off for a while. Any ideas please?

 

crankshaft pulley oil seal needs replacing - is one idea.

That's the 104 engine is it not ?

I replaced my crank oil seal.

 

Thanks for your reply. not sure what 104 engine is in ref to mine. My car is a L reg 94 w140 s class. If it is the crankshaft pulley seal, is it an easy or difficult job to replace?

 

The 104's leak around the head. Most of the time the leak looks worse than it is.