ford1991mustang

both freezeplugs on the back of my heads popped out...so i dont want to take anything apart lol
someone said there is some freeze plug that is rubber and fits to the size of the hole...is this true?
could it be donw with the engine in the car?

Bubba 95SN

Yes, they have a bolt that when tightened expands the plug. Clearance should be ok.

67mustang302

The big question though is WHY did they pop out?

mjr46

I have never had the ones on the heads leak or pop out.......was the car overheated bad???

mattdel

if both of them popped out at the same time, i'd be looking for excessive cooling system spike pressure, like a head gasket combined with some detonation from overheating.

ford1991mustang

i think they came out because there was water in the radiator and sat out during winter.
i installed the expanding freeze plugs and leak is gone. thanks

67mustang302

Freeze plugs aren't there though to pop out if it freezes...they're technically core plugs and are there to get sand from the mold out of the part after it's been cast. If freeze plugs pop out, there's a possibility that something may be cracked, so check to make sure there's no air bubbling in the radiator, coolant in the oil etc.