I've got a 1997 GMC Sierra 5.7L that we bought from a friend. I noticed that when you shut the engine off, a small puddle of oil will spit out. It does not continually drop oil or drop while the engine is on, but only drops this small puddle when you shut off the engine. The puddle size is really not very large, but definitely large enough to get your attention when you move the truck.

We took it to my mechanic and he replaced the upper and lower oil cooler lines, but the oil is still dropping. I asked him to look at it again to make sure the lines were seated correctly and he said they were.

Can anyone lend some advise as to where to look next for a solution? I know this maybe a broad question without looking at it, but this is the first time I've had this issue on any of my GM cars. Thanks in advance!

How about the oil pan gasket? When running the oil level is a bit lower because it'* moving threw the engine. Shut it off and the level moves up a bit.

Please help us by telling us where under the truck the spot is located. Surely if it'* by a rear wheel...then we'd have different ideas than if it were up by the fans.

The leak is in the front under the engine. It looks to be about in the middle - passenger side. Nothing leaking from the rear.

If it'* where I'm thinking, the oil filter, main seal, and timing chain cover are all in that area. Wipe everything down real good. Then keep a eye on it for drips forming.

Thanks for the help. Just to clarify: if the leak was coming from any of these areas (oil filter, main seal, timing chain, oil pan), wouldn't the leak be continuous and not just a small bit of oil dropping? The leak does not continue dropping once the engine has been shut off.

When shut off, most of the oil drains back in to the oil pan. So if the leak is above the pan, it won't be more then a drip after the engine is turned off.

Thanks for all the help! Turns out a bad oil pan gasket was causing the drip.