How bad is this (car question)?

Newton

The car is a '99 Toyota Rav4 with about 98,000 miles. I was changing the spark plugs and plug wires today. Three of them were fine but one of the spark plugs was covered in oil. It was all over the threads, but not the tip where the spark is, and the exterior portion was really nasty, too. The picture below is of the one bad plug and one other plug, but the other two that I pulled looked just like the cleaner one. It's hard to tell in the picture, but the tips where the spark is look the same on both plugs.

I checked the oil and it was a bit low, but it's also been at least 5,000 miles since I changed it, so it doesn't seem to be losing oil very fast. How is the oil getting in there and why is it only the one cylinder? How worried about this should I be?

http://imageshack.us/photo/my-images/191/img1153po.jpg/

Figgy

It's most likely a very easy fix and nothing to be worried about. I am not a mechanic, though.

There should be gaskets inside the holes where you replaced the plugs. The one that was dirty will most likely have a worn valve cover gasket. Depending on the engine, it should be fairly easy to fix yourself.

If you don't get this fixed, however, you could run into problems down the road. True, the oil isn't getting onto the actual spark plug tip, but eventually it could. It could also wear away the spark plug wires, etc. Then you're looking at misfires and possible damage to your engine. If you google "Valve cover gasket replace" and your car/year, you should get some decent info.

You could also just call around and see what a mechanic would charge to do that. Just grab the parts yourself and it should be an hour of labour.

Newton

Thanks, Figgy. I've been doing a little more research on the car and it looks like you're right. Fortunately the gasket set is cheap and it looks pretty easy to replace.