I've got me a decent oil leak on my truck. The oil spray manages to reach all the way back to the hogs head. While I had it at the local Jiffy Lube, I went under to take a better look. The technician said the oil leak was coming from the drain plug and that I should get it fixed sooner than later. I had thought it was coming from higher up on the engine, say around the rear main. Considering he is much closer to being a mechanic than I am, not much though, I figured I'd bring his prognosis here. Is it possible for a leak at the drain plug to spray oil upwards?

Don't worry, I took my own Napa Gold with me.

At highway speeds, I've found oil can go everywhere. (After driving an extended drive, I have oil spray all the way at the top of my campershell glass.) Of course if it's a /lot/ of oil, I'd say it's probably worth checkin stuff higher up. Considering the cheap price of a drain plug though, I'd say it's worth a shot either way.

The only way oil can spray up against gravity is if theres a driving force - pressure from the pump, wind, etc.

Oil at the drainplug isn't pressurized. I'm guessing, if the back of the engine is soaked, then its either the rear main or the oil pan.

The threads don't seal the drainplug, the washer does. Replace the washer with a copper or plastic unit designed for the purpose. Hardware store item.

Follow Stryker's lead. Airflow under the vehicle, even at surface street speeds, can splatter a drip all over the underside. Go ahead and replace the drain plug and washer. Do a good cleanup of the engine bay and underside, then drive it around the block. Crawl back under with some decent lighting, and you should be able to see if you have more than just a drain plug leak.

Roger