oil on my spark plugs?
 

Okay we just done the tune up and when we removed the spark plugs 4 of them had oil on them, like down in the engine part or whatever it is. Is this bad? My jeep isn't smoking or anything.

4.0L?
If the valve cover leaks then oil will build up around the outside of the plugs.
No biggie.

X2, five bucks for a new valve cover gasket, ten bucks for a new CCV and grommet and some time to do the job. You will have to break off the CVV in order to get the valve cover out of the engine bay on a Grand Cherokee, and be careful not to break the temp sender off at rear of the head on the driver side.

You need to at least post up the engine you have...

4.0 v6

There is your problem... you either have a 2.5 v6 or a 4.0 I6. A 4.0 v6 never existed in xj's EVER. LOL For your problem look up a spark plug chart and it will tell you what that is usually from

I have a grand Cherokee laredo if that even matters.

What year is it? That may help us more with knowing what engine.

Here look at this chart, it should help. ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

98 4x4

Is the oil on the plugs above or below the threads?

Um its covering like an inch of the plugs

Your valve cover is leaking.