What is a freeze plug and are there any other names for it?

 

Freeze plugs are used to prevent damage to an engine block if the coolant freezes by popping out when the coolant expands.

 

other names I've heard...besides freeze plugs are soft plugs and expansion plugs. I think freeze plugs are the most commonly used term.

 

yea, freeze plugs are what they are commonly called.

 

They're not officially called freeze plugs and they're not there to pop out if your coolant freezes, they dump the sand out of the engine from the mold when it's cast through the openings then plug them up. A couple years back Jeep had problems with their 4 liter engines because they weren't getting all the sand from the mold out of them.

 

I agree. Look at where the 'freeze' plugs are on a rotary. a few ont he front plate and a few on the rear with one on the intermediate. If the water were to freeze, I bet it would do a lot more damage than simply pushing out the plugs.

There are also plugs on the intake manifold, but they are threaded allen head type plugs. What's really perplexing is that there is a 'freeze' plug on the intake elbow of a 20B. Lol, it's completely hollow inside. Why it needs a 'freeze' plug, I'll never know, unless it's a great spot for a blow off valve or something.

 

well,this hole i have has no threads and its about the size of a quarter.I dont have a pic but its about 1 foot away from the oil drain nut.

 

It's probably what everybody commonly refers to as a freeze plug, I wasn't disagreeing I was just correcting the misinformation about them, they're not there to push out if coolant freezes, they're there to drain the mold sand out of.

 

It's true that the holes are there due to the casting process but the plugs will pop out if the coolant freezes. You think this never happens?

 

does anybody know the size of the freeze plug i need?
its a 85 GS

 

bump

 

anybody?