Fixing a Persistent Oil Leak

After replacing the valve cover gaskets, the oil pan gasket, and the entire timing cover set on my 1999 Cougar 2.5 V6, I still had a pretty bad oil leak. It was coming from somewhere on the front of the engine and I couldn't see it dripping with the engine idling, but it would leave spots on the driveway and there was oil all over the wheel and down the side of the car.

I finally had time on Saturday to tackle the oil leak. So I jacked it up and set it on jack stands and let the car idle as I poked around with my flashlight, looking for drips.

We used a hot water pressure washer to clean off the oil the night before. I then drove it and when I came back, there was lots of fresh oil on where we cleaned.

So I was kind of perplexed when I couldn't see any drips with the engine running, yet there was plenty of fresh oil on the car. So I decided I needed to look while the engine was running at 3000 RPM. The first place I watched was the front crankshaft seal. As soon as the engine revved up, oil started oozing out of the seal.

I thought it wasn't that seal, because I had replaced it a while back (and it didn't stop the oil leak, obviously). So this time, I resurfaced the crankshaft pulley where the oil seal rides.

I used a scotch-brite type pad on a die grinder to resurface it. There was a small dent I was worried about that you can see in the above photo. But after getting it all back together, we revved it to 3000 RPM and there was no leak from this seal. What a relief! Now I can get my driveway clean again.

The oil leak was only persistent because I thought my previous repair was successful, and hadn't verified it wouldn't leak at high RPM.