Help..freeze plugs poped out..did I mess up?

[PrettyFly]

I had my car all rebuilt paint/ground fx/etc..and a rebuilt 306 pretty much stock. Last summer. I was not completely done, so I parked it covered for the witner. I was originaly having problems with the motor knocking. It was good weather while I was fixing it up so I had a 50/50 mix of anti freeze and and water. It got cold when winter came and half of my freeze plugs poped out!!! Does that mean my block must be cracked if that happens? Anyway of really diagnose it while its in the car if the block is toast? Any advice would really help.

Thanks
Josh

 

[Rick 91GT]

It's a touchy situation, the plugs are there so they pop if it freezes but you may have done block damage. Is there any water in your oil? You can get new freeze plugs, install them, then file up the motor, do a compression test and a leakdown. They also sell a fluid that is a dye that you add to your coolant so you can find cracks/leaks.