I think the only way to tell is to remove the converter cover (if auto) and wipe the entire area down with a dry rag then start the car until you see drips on the floor. Then shut off the car and crawl back under there with a flashlight. At least that's what I have to do. When I had the engine out I put a brand new steel pan on in place of the chrome after market pan the leaked real bad. I wiped all surfaces with laquer thinner and used the cork seal in the groove at the back with 3M super adhesive and snugged the pan on overnight. Then a thin bead of Permatex 2b on block to gasket and snugged and let sit. Then a real thin smear on pan and just snugged up the bolts. No leaks on initial startup. Have run the car a few times and no leaks. The other day was letting it idle and reved it a couple of times. Small f'in oil puddle. RRRRRRRRRRRR! Maybe the bolts just came loose a little? Please?
