I know this is going to be a very open-ended question but on my MOT I got an advisory for an oil leak, which I had a quick look for yesterday. Got underneath and took the undertray off only to be confronted with oil seemingly everywhere! There seemed to be a film of it on the bottom of both the gearbox and the sump, none of which looked particularly fresh...

I've cleaned everything up a bit with some blue towel for now so hopefully when I do the same thing in a week or so (time permitting) I might be able to see where oil has re-appeared, but are there any particularly common places for it to leak from? The sump seems fine, not cracked or damaged, there didn't seem to be any oil around the sump plug so I don't think that's been fitted wrongly causing a leak, and I'm stuck for where else it might be coming from unless there's a clearly visible source next time I check underneath.

Perhaps when the oil was last replaced It may have over flowed and run down the back of the engine !

DB.

Hmm, possible, although surely by overfilling it to that level, you'd notice problems (I remember when I overfilled it slightly and asked what damage could be done, "oil churn" was a concern for people who knew the ASZ engine design in that it would be possible for the crankshaft to contact the oil)? I guess maybe spillage rather than overflowing is a possibility though, I'm just confused by why almost the whole of the bottom of my engine was coated, unless it's collected in the undertray and spread about from there. Which I would have thought unlikely due to the numerous squares that make up the undertray, I'd have thought the oil would have just run around in the channels between the raised squares and not really come into contact with anything.