As I mentioned yesterday, oil leaks are common on any brand of engine. There is something wrong if this is the first leak you've had in 286,000 miles. Look at any car in any salvage yard and you'll see oil on the engines that have less than 50,000 miles. Look on the ground in any parking lot and you'll see the evidence of all the cars with oil leaks. This is nothing uncommon.
Gaskets shrink with age and heat, and they dry-rot over time. Also, there are a number of different designs. The 3.0L in my '88 Grand Caravan uses reusable rubber gaskets. When they start to leak, there are two bolts to tighten a little. When removing the valve covers, those gaskets do not have to be replaced.
Older engines often used cork or hard rubber gaskets that were damaged when they were removed, so they had to be replaced when they started leaking. A lot of newer engines, meaning since the late '80s, use a silicone gasket sealer from a tube to seal valve covers and other covers. Those can take a lot of work to peel off, but they rarely leak. The biggest thing you have to watch with that style is all the metal surfaces must be free of any hint of oil residue. Some of those silicone sealers won't bond and seal through a film of oil. That will result in a pretty large leak right away.
The only reason I mentioned cleaning the engine was so you can see exactly where the oil is leaking from. It's hard to tell when everything is covered in that residue. If you see oil all the up by the valve covers, it's a good bet that's what's leaking. Just replace those gaskets for now. The oil on the engine will start to dry up. It will collect dust and road dirt which will cake on the engine. That can be washed off later when the weather is warmer.
Monday, March 2nd, 2015 AT 2:43 PM