Cracked engine blocks can be embarrassing and confusing. It can be embarrassing because the most common cause of a cracked engine block is not having the proper mix of coolant in your engine. Too much water (or only water) will keep your motor cool in the summer, but in the winter it can freeze. We all know water expands as it turns into ice and that expansive force is enough to crack even the toughest engine blocks. So don’t be silly and make sure you’ve got a good mix of antifreeze in your vehicle’s cooling system to keep your engine block safe this winter. If you’re concerned about your coolant’s freeze tolerance, it might be a good idea to flush your cooling system and add new coolant.

We want to make sure you’ve got a good understanding of what your options are for repairing your cracked engine block. Join me, Clark, in the garage where I’ll walk you though your options for repairing your current engine block.

We also want to make sure you know how you got a cracked block in the first place, so we’ll talk through the possible causes of a cracked engine block also.

Causes of a Cracked Engine Block

  • Freezing
  • Thermal stress
  • Shock loading


We already talked about how having the wrong mix of coolant in your engine can allow it to freeze up and crack. Most local auto parts stores sell a test kit that includes either a test cylinder and float or chemical test strips that you can use to check your coolant’s freezing point. If you’re concerned about your vehicle but don’t want to flush your entire cooling system, try picking up one of these tests for some peace of mind.

Thermal Stress

Besides cracking from water freezing in the cooling jacket, your engine block can also simply crack from normal use. The heat and cool cycle your engine goes through every time you start it puts stress on the metal your engine block is made from and going through that enough times can eventually crack an engine block. Keeping your cooling system working properly is the best way to reduce the risk of thermal stress cracks in your engine block. If you’re worried about your engine running a little too hot, try adding BlueDevil Engine Cool to your cooling system to reduce temperatures.

Shock Loading

Like any other metal component, a good shock to your engine block can cause a crack. Things like a hard launch in your car, slamming through gears in a manual transmission or shifting from reverse to drive too quickly can often send a huge shock through your engine block. If you’ve got worn or torn motor mounts this can cause even bigger loads to be placed on the block and could eventually cause cracking. If you want to make sure you don’t end up with a cracked block, be nice to your car!

If for whatever reason you end up with a cracked block, check out my video below to find out what your options are for repairs! Don’t forget to check out the rest of my blogs for other amazing tips and info about inevitable car issues.

pictures provided by:
cracked_engine_block.jpg – By Phuchit – Licensed by Getty Images – Original Link