[MegaMax]

Another thing you can do is go to your local Parts store and pick up some De-Greaser (2 cans should do the trick)
Find a local SELF carwash and with the engine ON and it warmed up pop the hood and spray the cleaner go nuts with it and even get under the front (where Oil pan is)
Then rinse it all off (follow instructions on can)

With it all NICE and clean drive home, if the Leak(s) is bad by the time you get there you should see where it's leaking from.

If it's the plug replace it should be under $5.00 at your local dealer.

As mentioned above when I bought my van with 149K here is what I did...

Bought the cheap motor oil (whatever was on sale of 5-30 wt) and changed it every 1000 miles two times. WHY: I didn't know when it was done last and how frequent it was done, by doing this it "flushes" out whatever tiny debris may be at the bottom of the pan. Then I bought a bottle of Slick50 High Mile formula and again changed the Oil and added that to the mix... This stuff like any Oil Additive is NOT great for your car. Search on line and you can find tons on articles on it a quick note on it... If it's designed to "coat" your engine to "Protect" it... that means it's thicker than the conventional motor Oils. when your parts need lubrication the most is fist thing when you start it, the oil pump has not been running and the oil that was on the parts has run down to the bottom of the Pan overnight... still with me... OK now you have this COLD (from lower night temperatures) thicker (from adding this "great product") motor oil in your Oil pan... Well because it's colder and thicker it will take longer for it to get to operating temperature and fully recoat your internals. (I hope I didn't loose ya there)

Anyway, I left that in the engine for a whole 2000 miles and then I switched to Castrol SYNTEC BLEND 5-30 and the X-2 filter and now change it every 5K miles.

I also changed the Air, PCV, and Fuel (wait to ya see the price on this one) filers Plugs and wires. Personally I went with the 4x Plugs offered at Pep-Boys.

Finally because of what I read about the Transmission on our vans I bought a Trans-oil cooler and new Tranny filter and did some preventative MAINTENCE there as well.!

Next for me are all of the hoses and vacuums on it. It's TOO cold out for me to work on the cars now so I haven't done them yet, but I plan on flushing out the radiator and replacing the hoses on it.

Most of the above things you or anyone can do, simply get your Chilton's or Haines manual whatever one you buy and look up the task you want to do and get to it.