that plug is not for freezing, its for when its manufactured so they could drill/machine through the side and then they put a cover over it, the glue doesn't hold well under the pressure of high rpm use.

 

Why would the water/coolant freeze? What are you folks doing to your cars?

 

Parking them in places where it freezes in the winter.
How's the weather out there in Arizona?

 

 

Actually freeze plugs are the correct term. They are there for a reason and designed to keep your block from splitting in two when it freezes (aka you park it outside in Detroit when it’s 50 degrees below 0 and your dumb *** filled the block with straight water). If you think these are holes to “shake the casting sand out” you should go look at open deck blocks. I can shake a can of tuna fish into the open deck of an open deck block, much less sand. But they still have freeze plugs…why. Cause you need them.

Also, usually freeze plugs are made of a different metal than the host orifice (usually brass in an iron block). This different metal will have a higher thermal expansion rate than the host material. Which means that as the block gets hot, the freeze plug expands more than the block and locks itself in place harder. As the block freezes, the plug contracts more than the block and gets loose. Then the force of the ice freezing (and water expands when it freezes) pushes the plug out.

I’m not sure what the material of the plug is on that aluminum water pump, but there may have been a batch with the plug or the orifice of the wrong diameter, or the wrong material. Look at this list of materials and their thermal expansion rate when exposed to heat:

· Aluminum – 13
· Brass – 11
· Copper – 9.4
· Iron – 6.7
· Steel – 7.2

Notice that Aluminum expands the most out of common metals when exposed to temperature changes. This is also easy to see why an iron hole with brass plug will actually have the plug get tighter when exposed to heat. The brass is expanding at almost twice the rate that the iron is. What this means is that to get an effective plug on your aluminum orifice you have to go to an exotic material (which is cost prohibitive); or you change your plug/orifice relational diameter to make the fit tighter to begin with.

My guess is they had a bad batch of pumps in 2005 that had plugs that weren’t tight enough. Then when you built up pressure in your cooling system you would pop it out.

 

"Core plugs" are actually the correct term. They are not there to save your block. They might save your by chance but thats not their purpose. freeze plugs IS a misnomer.

 

Core plug, freeze plug. Either way I still know what you're talking about. Not everything needs to be named after their primary function.

 

That plug should never come out. The weep hole should leak before that plug comes out.. if it does then the waterpump is defective. I had issues with my oring'ed head not sealing properly and it blew the seals in my pump when the head was lifting and replaced pump and retorqued head, and keep an eye on head and been good ever since. Its pointless to plug that plug off unless you know you have one of the pos old waterpumps from mitsu when they had issues back in 2003-2005 or so.

 

best post in here.
but most can secure freeze plugs and not worry about block cracking from freezing. I live in florida. its never gonna get that cold.
plugging the water pump is a good idea.
a lot of blocks that have plug blow out are from mechanics that dont know how to install them. most stretch the caps during install. they use a socket to drive them in which is a bad idea. they dont stay in like factory install without the tension to hold them in. they need to be driven in by the rim.

I also agree 100% all plug blow problems are from poor tuning and lifting the head. water jackets are only to see 15psi. combustion pressures are 2000psi and 4000psi when engine is seeing detonation. it doesnt take much head gasket seepage at those pressures for the water jackets to see far higher than 15psi.

 

do you really think your freeze plug expend before your water hoses??

or even your plastic radiator??

 

Go back and re-read...they aren't there to save your $200 radiator, or your $20 hose. They are there to save the block.

 

yes,like i say:
the hoses or even the radiator will broke a long time before the block!

and if one or both broke,there will be not enought water/anti-freeze to broke the block!

 

Wow, you are right. I can't believe we have been doing this to blocks for the past 80 years. And EVERY engine has them, and every mechanical engineer out there that has designed blocks has never figured out a way to do without them.

But YOU are right; YOU are smarter than the entire automove engineering community that has thousands of years of combined experience. You sir should take over GM and make them profitable. Because if you, in your lone wisdom, can figure out what thousands of engineers before you couldn't....imagine what you can do to a company that has so many problems.

 

a properly non defective waterpump will blow the seals inside it and cause the weep hole to leak before it blows the freeze plug off.. get real.

 

i'm not an engineer,but i put anti freeze in my car!!