It's getting to be crunch time for the Olds Nationals, and the hits just keep coming for my 94 Cutlass. This time it was the oil drain plug leak. There always has been a leak in that area, and I had it checked out, and was told it was the rear main seal. Fair enough, but I was still suspicious of oil leaking from the plug/bolt. I went to change my oil and noticed there was an ill-fitting bent and crushed copper ring laced with black gasket sealer. No doubt one of my brother's inventions when he owned the car. For my part I failed to notice this when I first changed the oil upon receiving the car back from him. I'll give myself a pass on that as I changed the oil in 4 additional cars that day.

Anyway, I changed the oil and put the plug, the original 30 year old plug, back in the car with no gasket. Big mistake as the next morning I was shocked to see the amount of oil that leaked out overnight. I checked with this C/O site for ideas on what to do, and I found 3 alternatives for a gasket: Teflon/nylon (plastic?), rubber, copper. Using a new Dorman bolt/plug, I went with (a new) copper gasket first, and it cut the leak down considerably, but not completely. So, I swapped that for the teflon/nylon (plastic?) gasket that came with the new Dorman bolt, and now I have no oil leak at all coming from the oil drain plug.

Thanks to the advice on C/O which is very much appreciated, some takeaways:

* Your original drain plug does not last forever; 30 years was way too long to install a new one; these things do go bad after time.
* Ideal to use a new gasket with every oil change.
* Alternatives are copper, Teflon/nylon (plastic?), rubber
* Before a new thread is opened up on a repair topic, check out if something already exists on the subject via entering the issue above right in the Search Threads box.

I'm now ready for the next thing the car is going to throw at me before we leave for Springfield next Monday...........

 

Good to hear that you got the leak fixed. 👍

 

Yes, I recently got a 3 pack of the plastic washers at the flaps, 1/2" for my Olds 455.didn't like the copper rings, bottom of pan isn't real flat anymore and ID of ring was too big so it floated around while tightening.