Huh? Worn? I seriously doubt that. I would think you could remove and install a drain bolt 100 times without wear. (Note: I'm assuming steel oil pan here.. I guess it's possible for an aluminum oil pan to get stripped out after repeated insertions. What is your oil pan made of, aluminum or steel?)
First off the primary seal for and oil drain bolt is the copper (and sometimes plastic) washer between the oil pan and the bolt head. It's not the threads of the bolt. Generally you use a new copper washer with each oil change.
More likely scenario:
Some mechanic dropped the oil drain bolt at your fast lube station, and grabbed some other bolt, with different threads. They forced that in, perhaps used a tap to recut threads to match, and now that's just a very loose fit. Its also possible that your oil pan drain plug area hit a rock in the road, and this is causing problems. This is bad, as it is possible for a drain bolt to just fall out, later. If that happens when you are on the road, you've got mere seconds to stop the engine. Remember when the oil light comes on, that doesn't indicate a low oil condition, it indicates there is zero oil in that engine. My belief is that if you run that engine even 60 seconds without oil, the engine is destroyed.
- It sure would be nice to have the correct drain plug with correct threads in there.
- The best thing to do is remove the oil pan and get this carefully fixed. If it were me, I'd fill threaded hole in the oil pan with TIG (Tungsten Inert Gas) welding and recut the threads. I'm decent at TIG in both aluminum and steel. But to have that done would be expensive.
- Another choice is to just buy a new oil pan.
- It sure would be nice to know exactly how loose that drain bolt is.
- I guess you could purchase a new drain bolt, go to a quickie oil change place have them drain the oil. When the oil is drained, test the current drain bolt to the new one you've just bought to see how "loose" it is.
- Piece of mind is certainly worth the price of an oil change and a new bolt.
- If it's crazy loose with both bolts, do the drain pan removal and repair.