did i crack my block

[69chevytrucker]

long story short built a 350 put water in the rad to test it got busy forgot water in it . i moved it in the spring and found a frost plug on the ground. i put a new plug in. just getting it ready now drained the oil engine only had about 30 kms on the build just one test run. no water in the oil or filter so i put new oil and filter i just started filling the rad with water for the first time since the new frost plug was put in a year later. water started pouring out the water pump weep hole and some drips out the block heater. i stopped and now im going to wait till tomorrow to see if i have water in the oil . what are the odds i cracked my block

[DBK81]

Sadly, I think you already know

[69chevytrucker]

i figured as much i have another block i guess i can pull the parts and not be out a full $7k

[68bowtie]

sounds like bad odds. but maybe only the pump and heater are shot?

[MARKDTN]

If no water in the oil you may be OK.

Long story short. Bought '95 Suburban in 2002 with about 100K on it. The first week we had it my wife was driving and the water pump died. It got so hot that it melted the temperature sensor plastic plug. I put another water pump and temp sensor on it and hoped for the best. We put another 100K on it with no issues whatsoever. a 350 is tough.

[Redline novdog]

I would try plugging the holes(water pump and block heater) Fill it with water and run it up to operating temperature, if no water in the oil, then replace the pump and block heater. Refill with coolant and drive on.Naturally if you have water in the oil, I would say your block is broke.

[trkfrk]

Sounds like the freeze plug may of done its job. I would change the water pump and then psi check the cooling system.

[my67c20]

Hmm, found freeze plug on the ground. What does this mean? Either it fell out cause the fit was poor, or some force from inside pushed it out. Odds are it was the second scenario, but how. Freeze plugs by design, are a good idea, but the location in most engines does not appear to be in the best design location. Actually most of these are nothing more than core plugs (of course some will debate me on this). I believe they are called freeze plugs because the engineers felt that if they called them core plugs gearheads would be like "then why do i need them", and weld them up, or just leave them open. Now, how many people have seen water freeze from the bottom up? Odds are not many, if any. So what happens inside your engine block, is that the water starts to freeze (change from liquid to solid) from the top down. As this happens it also expands, and requires the remaining liquid water to go someplace. If your lucky, this displacement actually pushes the plugs out, but because of air pockets, the water fills those voids, and compresses the air. However, water does not compress, and the surface area of the water against the plug, is far less, than the water that is freezing at the top of the cylinders or in the cylinder head. So most likely you have damage higher up than you may think, possibly some head or valley cracking. Some of this may not be in a critical area, and you may be able to run the engine with no short term affect. But is getting stranded with a blown motor a better choice than spending a few hundred on a new block, or testing what you have? Oh, and i am not a real engineer, i just stayed at a holiday in express last night.

[mike16]

those plugs are there to remove casting sand from the block after the cast iron has been poured and has solidified. Never have known of one to function as a freeze plug and pop out due to expanding frozen water....and save the block.

[Bigdav160]

+1 on what Mike said. They are called core plugs or welch plugs. They fill the opening that casting sand is removed from.

They are nicknamed "freeze plugs" because they tend to pop out if the coolant freezes. the expansion that pushed the plug out usually pushes in and cracks the block.

Yep, watch for water in the oil.

[trkfrk]

Psi test the cooling system, it will help you eliminate the guessing. You could also leak coolant into your combustion chamber and wouldn't mix your coolant and oil together. You can perform a bubble test to check for this.


Here is a quick Google search and I know all searches aren't accurate lol.

WHAT FREEZE PLUGS DO

As with many things on a car, there is an "official reason" and a "REAL" reason for freeze plugs. The official reason (and the source of the name) is this: If you run just water with no antifreeze in your car's cooling system the water can freeze. When water freezes, it expands. If water freezes inside your engine block, it can expand and crack the block, destroying the motor. Freeze plugs (or expansion plugs) will "pop out" and supposedly prevent this. In reality this doesn't work all the time: I've seen MANY blocks destroyed by cracking without the freeze plugs popping out, or if they do pop out the block cracks anyway.

[1972RedNeck]

Originally Posted by trkfrk

WHAT FREEZE PLUGS DO

As with many things on a car, there is an "official reason" and a "REAL" reason for freeze plugs. The official reason (and the source of the name) is this: If you run just water with no antifreeze in your car's cooling system the water can freeze. When water freezes, it expands. If water freezes inside your engine block, it can expand and crack the block, destroying the motor. Freeze plugs (or expansion plugs) will "pop out" and supposedly prevent this.

I would believe this if some engines didn't have threaded core plugs...

[Valarius_Starchaser]

Not to just throw a stick in your bike spokes here trkfrk but the whole "freeze plug" name and origin is often misrepresented they are in no way able to save a black and 1 in 1000 will do it and even then there is likely to be some other block failure/warping NEVER rely on them to do anything for you in the way of being a "magic block saver"


Their true name is a core plug

and...

The real reason for them to exist is due to when the engine block is cast with sand the holes are present to remove sand from the cooling passages nothing else

[trkfrk]

Originally Posted by Valarius_Starchaser

Not to just throw a stick in your bike spokes here trkfrk but the whole "freeze plug" name and origin is often misrepresented they are in no way able to save a black and 1 in 1000 will do it and even then there is likely to be some other block failure/warping NEVER rely on them to do anything for you in the way of being a "magic block saver"


Their true name is a core plug

and...

The real reason for them to exist is due to when the engine block is cast with sand the holes are present to remove sand from the cooling passages nothing else

I googled it. It must be true. Lol I am going to unsubscribe from this thread lol.

[mike16]

welch plugs... I could not remember that name. freeze plugs they are NOT. other than in name.

[69chevytrucker]

i know a frost plug is just for sand removal it was a dumb ass mistake that i forgot that i just put water in for a test and then let if freeze i guess i was just hoping someone would tell me a simple way to know for sure if i messed up my block cause i know that no water in my oil is no guarantee that it is not cracked.
btw thanks for all the input

[69chevytrucker]

so i just drained the oil and it had no water at all and the water level was full up to the weep hole on the water pump and i pull the block heater and a boat load of water came out and that was after sitting for 24 hours. so i think i might have dodged a big bullet looks like my water pump pushed the seal and my block heater had blown out the o-ring .
so with that even though a frost plug is not a frost plug i think it along with the block heater may have popped and dumped the water out before it caused major damage.
going to get a new water pump and block heater tomorrow and give it a try.
when i get it running i will update here.

[In The Ten Ring]

I spoke with someone that said you would probably be OK because of the cast iron construction. Heck, I think I even prayed for you last night as I drifted off to sleep!

[midniteblues]

I got my fingers crossed for ya.

I've seen it work both ways too if ya get lucky they pop out...
If not... well you know $$$$.

Get it running a keep a good eye on the fluids that will certainly tell the story.

[mike16]

me too. hate learning those types of lessons.

[fwayne]

Man hope you lucked out. I pulled a similar stunt back on my teens working on a Slant 6 Dodge. Little old lady car...supposed to change oil and replace vacuum lines. As I was warming it up and just finishing the vac lines I saw my 5 quarts of oil sitting on the bench...I had run the engine for about 10 minutes with no oil at all. Being the low man on the totem pole and needing my job, I poured the oil in, and that car came back for years for routine maintenance without ever knowing. Man those slants were tough!

BTW Ive personally had it go both ways. Core plugs pushed out and the block wasn't cracked once, and on another it cracked between each core plug.

The guys are correct those plugs are just freeze evidence, not freeze protection. Luck is a better factor.

[sawyerrm]

Originally Posted by fwayne

Man hope you lucked out. I pulled a similar stunt back on my teens working on a Slant 6 Dodge. Little old lady car...supposed to change oil and replace vacuum lines. As I was warming it up and just finishing the vac lines I saw my 5 quarts of oil sitting on the bench...I had run the engine for about 10 minutes with no oil at all. Being the low man on the totem pole and needing my job, I poured the oil in, and that car came back for years for routine maintenance without ever knowing. Man those slants were tough!

funny story

[Mrturner1]

I thought those plugs were in there to show me when I have used too much NOS

[GRX]

Sorry to hear this. Hopefully you got lucky. As others said, fix the weep hole issue, fill and run it to see what happens. No water in the oil means you probably escaped cracks in the lifter galley area. Next is to check the sides of the block for seepage.

Far as the plug purpose debate goes ... have seen countless blocks of many makes crack wide open with no movement of the plugs. The term "freeze plugs" is a hold over from the olden days with dish shaped plugs that sat against a shoulder, and were dimpled to hold them in place. They would pop out far more easily. Often too easy. Even so shape of the internal water jackets meant uneven expansion and cracks.

[dazza]

I was tired of stressing about it and made one of these... ;-)

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