Did the cap leak oil after using the tape? If not, suggest continuing to use it. I have used teflon on a bolt in an anto oil pan, without problems. Appearing to be dissolved may be the result of the pressure of screwing into the threads. A quote: "impervious to fuel and oil" as advertised by a large racecar supplies company, Jegs, and I would think that company should be aware of oil versus teflon tape. However, like almost all products we now use, China produces much of our teflon tape, and maybe disintegration is a better word.

fruitjarfla,
The screw on cap did not leak when I used the teflon tape. After removing the cap to drain the oil, I went to "unwind" the old tape before replacing it, and it just fell apart, making it difficult to remove all of it. Usually, when I remove something similar where water or air is used, this does not happen. This is why I asked the question as to whether or not there is a special tape to use that will stand up to engine oil. Thanks for your comments. I appreciate it. Charles Ranheim

HI charlie's, I'll try to ease your mind on the telfon tape theroy!?!... The teflon tape works well on PIPE threads. creating a seal so you don't have crank the plug is super tight to seal. There a small amount of tape that going into the oil beings the threads are tapered. that part is not sealing so don't worry about it.

FYI, I found a roll of Yellow Gas Line tape at Home Depot (Item # 078864177466) that should work on threads with engine oil. It is "For use on threaded joints of metal pipe handling Gasoline, Petroleum Oils, Propane, Butane, Naptha, Benzene, Kerosene, & Natural gas not over 100psig". When I change oil in my power equipment this fall, I will try it. If I do not use any tape, there is just enough seepage so that it picks up dust along the drainpipe. Take care, Charles Ranheim