As the title says, my brother's 86 IROC just dumped all the fluid driving down the road, come to find out the freakin radiator drain plug somehow loosened, drained all the fluid and fell out itself in the span of a 10 minute drive. No leaking or anything prior to this, no work done recently to loosen it, I don't understand how it got loose and came out... Hope the engine isn't fried.

Anyway, I need something to replace this sucker with, anyone know where the heck to go to get something to plug the hole? Know what thread/size it is, etc???

{EDIT} Pulled it out, apparently it's not even threaded, it's a specialty plug, has to be the exact right thing I guess. Dangit, gonna end up buying a new radiator, I can feel it...

Thanks in advance for any help.

 

I don't think I would trust it again unless it were threaded. I can't believe it's just a plug with no threads. Was it like a rubber stopper or what? That would be crazy.

 

I can't tell how the darn thing works, the fitting for it is funny looking. It's been awhile since I drained one of these and even then I didn't remove the plug, just loosened it, but I thought I remembered it twisting loose, which is why I thought it was threaded. It's rather strange looking.

Looks to me like the plug only goes in one way, turning it tightens it down somehow which it has an o-ring around the outside on the top, so I guess it pulls down tight onto the o-ring to seal. Beats me how it's works since it's not threaded...

 

well that thingy is called a "petcock" not sure if thats the right spelling but thats what it is and every car that ive ever drained antifreeze out of it twists out, and is completely threaded, so you may have a problem...... dont you just love thirdgens, it seems thats its ONE THING AFTER ANOTHER!!!!!!!! i cant believe how much trouble my car has caused, im glad i have a 88 Trans Am with a new radiator in it, mine cracked.....JB Weld cant withstand the pressure....ok im done babbling about my problems

 

Square hole in the radiator, right?

It's a two-piece thing that comes as an assembly. It snaps into the square hole in the radiator. I had one fail on my Bonneville, picked it up from a dealer. Couple months later, while looking for brake fittings at Car Quest, discovered they had them as well.

 

Thanks for the help guys, I got it taken care of. NAPA stocks the perfect replacement, not behind the counter but out in their general help section "Help Tree" at this NAPA. It is indeed called a "petcock" or "drain ****", listed as for GM/Ford, they had several different kinds but this one was the only one even close, and it appears to be the exact replacement.

Anyway, it turns out the old plug had broken off. It actually is threaded but only way down at the bottom of the piece that snaps into the square hole. Not like one would expect with threads all the way down. And it was broken only down at the bottom. That is what threw me off, the old one had snapped in such a way I couldn't tell that it was broken off or threaded until I pulled that piece out of the radiator (didn't realize it came out to start with...)

Anyway, for future reference NAPA has it $6. My local GM dealership said they didn't stock it anymore BTW.


Now to find out if the engine is blown later tonight when I throw all this back into the car... Who knows how hot the sucker got before my brother realized something was wrong and got it pulled over in a good spot (it cut off on him once). I am fully expecting a blown engine...

Thanks again for the help.