Rounded Head in Oil Filter Cap Drain Plug
 

2006 FEH

I have found that the head of the oil filter cap's drain plug has rounded out with use.

The Ford part number for the oil cap assembly (the drain plug is not available separately) is 1S7Z6A832BA and costs approximately $40.

There is a Dorman (Chinese made aftermarket) part number 917-004 available for around $12. There are repeated references to poor quality control issues in the Amazon reviews (mentioned in 6 out of the 14 current reviews) and I decided not to go that route.

Mazda part number LF01 14 320 A9U cross references to both part numbers above and sells for approximately $16. It's probably the same part as the Ford one and it has to be better than the Dorman, so this seems like the best choice.

Re: Rounded Head in Oil Filter Cover Filter Cap Drain Plug
 

I never use the drain plug on the oil filter cap anyway. I just unscrew the cap and let it drain into a pan. A failure of this part would be a disaster, so tread carefully.

Re: Rounded Head in Oil Filter Cover Filter Cap Drain Plug
 

I took mine off a couple times but realized there was no point. If the cap is taken off carefully, it doesn't really make a mess.

If the plug is in there tightly, I'd just leave it an never open it again.

Re: Rounded Head in Oil Filter Cover Filter Cap Drain Plug
 

Even if you don't drain the filter, I would still change the 0-ring periodically as it was not intended to be permanent.

Re: Rounded Head in Oil Filter Cover Filter Cap Drain Plug
 

I wouldn't bother. There are O rings internal to the transmission and engine that are there for life. What damages them is turning the plug.

Re: Rounded Head in Oil Filter Cover Filter Cap Drain Plug
 

My small drain plug is also rounded.

It has not been opened since 2007! no drips!

I see no point to it either.