I have a small weep in my rear engine seal...enough to leave it's mark on my driveway. I found a product made by Sta-bil that is for stopping leaks in diesel engines. Apparantly it "re-conditions" seals etc and stops leaks within 800kms of driving. It's also supposed to be safe with my Mobil1 15-50. I know no bottle holds a miracle...but has anyone had experience with this stuff?