Oil leak/loss of power

Hello Ladies & gents, I have lost my 4x4 virginity and purchased a '93 200Tdi Discovery. Bought off a friend (1 not so very attentive lady owner)! Is a bit old & little rough around the edges but a good ride all the same (not unlike another lady I know)

But, I have oil leaking from not sure where. Appears to be originating from back of cylinder head/gasket then running down & covering everything. I have cleaned area off, as best I could, with WD40 & rag but was reluctant to use power hose until I know extent problem. Also 1 of the pipes linking injectors/glowplugs(??) might have a small hole in it as it had a wet look to it after wiping dry and running engine.

So any ideas what might be the problem and am I barking up the wrong tree and talking nonsense?

And finally, and probably related, the poor thing loses power on inclines road/off-road is this connected?

Many thanks & please ignore my ignorance
Discodillon

best bet is have presure cleaned first and this will make the job of finding the leak sooner and you get less oil on your sunday best.

I have been given a new fuel filter that is off a 300Tdi, will it fit my 200Tdi?