Does anyone know what size/type the the coolant fill plug is for the 2.5L? The one ontop of the thermostat housing? Just had to drill mine out and I can't find it listed anywhere online in either parts shop or parts diagrams (like mopar giant).

I drilled it out with a 13 mm drill and there's still some bolt left between me and the bore threads so clearly I need to go get something bigger.

 

It's likely just a pipe plug. So, NPT threads..... 1/2 inch, or 5/8ths would be my guess. You can pick them up at your local plumbing supply store.

 

That makes a lot of sense. I did some measuring and checked the tap drill sizes against the existing hole and it looks like 3/8 NPT might work. A 1/2 NPT uses a 17-18mm drill and 17 mm is noticeably larger than the existing hole. A 3/8 NPT uses a 14.6 mm drill and since I have some bolt material left over after using a 13mm drill, the measurements show that 14.6 is in right ballpark. I'll try Thursday or Friday when the tap and drill set come in and report back so anyone seeing this in the future will know what worked for me.

 

Just updating the gang. It does appear to be 3/8 npt. Unfortunately my threads were in pretty rough shape even after chasing with the tap. The plug would seat but at full temp and pressure coolant would weep out. Not a crazy leak but no amount of teflon tape fixed it. I ended up coating the interior thread with JB weld, spraying the plug with pam no-stick cooking spray, and then screwed on the plug hand tight. The JB weld filled in the bad sections of thread and Ive been driving it around for a few days with no leaks. JB weld says it good up to 500F and the cooling system should only ever get up to 220 so I suspect it's a good long term fix if youre plug was as jacked up as mine.

 

Maybe try a crush washer.