The gasket of the cam cover and the cover seals towards the oil filter housing age, harden and start to seep. On the M112 the oil loss around the cam cover gasket is a big theme in itself. The oil runs down the side and the front of the engine. The visible sign is an oil patch on the floor and an oily engine bay. The leak starts slowly, but the running oil can also get onto the belt drive and the exhaust. The part is not expensive: each of the two cam cover gaskets was around 18 euro. A lot depends on the quality of the repair. The covers of the crankcase breather on the cam cover are held by aluminium screws, and those break easily if someone leans on them: they may only be tightened gently by hand. The fault comes up above 130,000 km.