Since it snowed the water in my 95 gmc Sierra 1500 froze and cracked the block at the top and I went to fill the radiator up and everything just poured out on the side of the motor but you have to look under the truck to kind of see where the water is coming from can anyone please help..

  • 2
    Welcome to Motor Vehicle Maintenance & Repair! I'm not sure what exactly your question is, or how we are going to be able to help. If you've cracked the block, as you've indicated, there's only one real fix, and that's replacement. Luckily for you, GM built about a billion small block Chevy engines which will fit right into your truck. Getting one should not be overly expensive, nor hard to replace. If there's something specific you need to know, please edit your question and include the pertinent details. Jan 11, 2018 at 23:26

2 Answers 2


There are numerous freeze plugs in a typical GM block. the good news is some are readily replaceable. There are two bad points though. First point, the ones that aren't easily viewable are a pain to get at, think about how to look at the back of the block in front of the transmission or how easy will the exhaust manifolds come off. Second PITA point is they rarely fail from freezing. You may be lucky that one actually failed from age or rust and the ice popped it out.

  • Are these "freeze plugs" and located at points of possible failure or are they Casting Plugs used during the casting process and not necessarily there for protecting the block?
    – Solar Mike
    Jan 12, 2018 at 9:36
  • As I commented they are referred to as "freeze plugs" but rarely open in time to prevent block damage.
    – mikes
    Jan 12, 2018 at 15:02
  • It’s just that I have heard them called « core plugs » ...
    – Solar Mike
    Jan 12, 2018 at 15:03
  • They are made to remove sand at the foundry. The name "freeze plug" is basically PR. Jan 12, 2018 at 19:07

If you want a hand pinpointing the leak you could add some UV Dye to the radiator and get a UV light to illuminate it once the leak occurs and track it to its highest point. This is usually for small leaks, but it should work too for a large leak like yours that you don't want to confuse with other liquid sources. You may get confusing results if the leak is large enough that the pressure causes a spray blast that could obscure things. The simplest detection is a dribble leak, but a spray of dye you'd need to do some splatter pattern forensics of sorts to backtrack the true source.

A product such as Interdynamics 375CS Radiator/Coolant Dye - 1 oz. Bottle would lend a hand. Watch Scotty Kilmer demo the thing here.

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