coolant pipe drain plug thread size. (Page 1/3) AL87 FEB 04, 07:31 PM wondering what the thread size is for the drain plugs. AL87 FEB 04, 10:10 PM Also, wondering if there is a dorman/help assortment or something I could get. I cant afford to wait for shipping of OE reproduction parts. TopNotch FEB 05, 12:11 PM My guess, without looking, is that the threads are some size of NPT thread, and that a threaded plug of the right size from the plumbing dept. of your nearest hardware store will work. NPT threads are commonly used in such applications (threaded plugs used to seal water), such as plugs in engine water jackets (even if the rest of the engine is metric). tesmith66 FEB 05, 01:10 PM I can't believe you got the plug out. I have tried several, and ended up stripping the head out every time. AL87 FEB 06, 08:18 AM quote Originally posted by tesmith66: I can't believe you got the plug out. I have tried several, and ended up stripping the head out every time. who says I did, the plug where the allen wrench goes rusted straight through, its toast, time for a torch and easy out. tesmith66 FEB 06, 12:33 PM More like a drill and a pipe tap. Or a welder. AL87 FEB 06, 04:49 PM quote Originally posted by tesmith66: More like a drill and a pipe tap. Or a welder. damn' lol, don't jinx me. VikingRedBaron FEB 06, 09:34 PM quote Originally posted by AL87: who says I did, the plug where the allen wrench goes rusted straight through, its toast, time for a torch and easy out. If the plug rusted out, how good is whats left of the pipe? AL87 FEB 07, 12:42 AM quote Originally posted by VikingRedBaron: If the plug rusted out, how good is whats left of the pipe? well actually, everything went well, the original plug was almost rusted completely out on the 85 gt I was making a service call to, I used a torch to heat it up, and when I tapped in the correct tip to try and begin ratcheting it out, it just came out after a few full turns. I wasn't expecting this one to just come out like that, and I pulled all 4 plugs from a parts car I had sitting here with no problem at all. I chased the threads with a tap and put in one of the plugs I pulled. and used thread sealant... I guess I'm lucky to be in florida working on fieros that haven't seen the salty northern winter roads. Fierobsessed FEB 07, 03:28 AM 1/8" NPT. In my experience, I remove mine by inserting the largest hex key that will fit, and I will pry it around in all directions to widen the hole until I can fit the correct 3/16" hex key. Then it comes out without too much trouble. They are a blessing when you are draining coolant for removing the cradle