on my 2002 jeep grand cherokee there is oil (quite a lot) all over the passenger side, it looks like its coming from somewhere up top because it is splashed all over the oil filter, please help?

you probably put your oil filter on too tight and now it is spitting oil out of the crack, simple fix, change your oil filter, after that use degreaser to clean up all the oil as best you can and when you first start the jeep check for leaks, should be easy to spot if you clean up good, but it probably won't leak if you just hand tighten your oil filter(don't use that tool everyone uses, that's what cracks them

First as the "Robert" said, degrease the engine. You need it clean so you can see where the oil is coming from. As most Jeep Grands are over 100K now, the valve cover works its retaining bolts loose. Sometimes by following the factory tightening spec, (middle bolts to outer bolts) you can stop the valve cover leak, but if it does not work, you have to replace the valve cover gasket too. As it usually is leaking at the back of the engine and can run down the firewall and find entry into the vehicle if you have holes or other in the firewall. WARNING, if you choose to replace the valve cover gaskets, FORGET aftermarket gaskets, many are bad. Only use MOPAR, (Chrysler -Dodge) gasket for a good result. Replacing the valve gasket can be challenging with all wiring and tubes in the way, but its just a tedious job. Any doubt, get a mechanic to replace both valve cover gaskets, (V8) , if you have the straight 6 engine, very easy to do yourself.