It's been a while since I've posted a question here so see if you can advise on this. I was changing the old autobox oil the other day (it was showing signs of tiredness after 20k) I noticed that the engine castings just below what I would call the rocker box/camshaft cover were full of oil. This has got nothing to do with the gearbox by the way. The car doesn't seem to use much engine oil between changes so I'm wondering whether it's the usual gunge that comes out of the oil cooler but just leaking out of some other breather in the vacinity of the top of the engine. The cars always done this but I'm just curious to know where it comes from? Any suggestions?