MB sells an " Oil Kit" for this engine.
When you remove the cap and rotor Check for cracks and wear. There is a plate under the rotor. Remove the socket head cap screw, apply some penatrating oil and using a plastic mallet tap the plate untill it comes off. The plate is keyed so dont sweet the positiion. Pry out the supressor cover and "o" ring. The "o" ring resides between the plate and cap. Note the seal behind the supressor cover.
This is where the "oil kit" comes in. There are several attaching bolts .......remove the front Camshaft plate. The cam seal dries out causing oil to leak into the distributor cap. Shorting out the ingnition system. E-mail me for pictures. Replace this seal. Also there is a Flat gasket at the bottom of the casting that needs to be replaced. Note that the sides have no gasket. This is a machine fit. I wiped a thin film of silicone sealer on the surface anyway. Replace the valve cover gasket as well This all takes about 45 miniutes.
By the way ......I bought my car below wholesale because the dealer thought the engine was bad.!!