It’s fair to say that hearing the phrase “blown head gasket” is enough to paint a picture of huge dollar bills in your mind, either from personal experience or hearing about it from a friend – whose car had a blown head gasket – and the repair cost made you wonder if a car is even worth driving.

Why is a blown head gasket repair cost so high?

Well, that’s why we’ve taken time to explain everything you need to know about blown head gaskets, the symptoms, repair costs and more in this article…

What is a Blown Head Gasket?

If a blown head gasket sounds like bad news to you, that’s exactly what it is. The head gasket is a vital component of your car engine. It’s located between the cylinder head and engine block. The head gasket is responsible for sealing in the combustion process and the areas where the oil or coolant would pass through your engine. Your head gasket is declared ‘blown’ when it fails to seal the engine properly. This could lead to engine compression problems, causing coolant to leak out the sides of your engine. Without coolant, your engine is bound to overheat quickly.

What Causes a Blown Head Gasket?

  • Heat and Mechanical Stress: The engine of your car, while under operation, would produce a lot of heat. When there is a difference in the rates of heated expansion between your cylinder head and engine block, the head gasket is subjected to plenty heat and mechanical stresses that would slowly wear it down – leading to cracks and leaks.
  • Vibrations: Your engine’s natural vibrations and the ones generated as you drive can over time affect your head gasket. Your head gasket bolts – which keeps the head gasket tucked between the engine block and cylinder head – can begin to stretch, allowing increased friction and wearing out.
  • Overheating: When you allow your coolant level to run low, your head gasket can get damaged. When coolant isn’t made available to remove heat from your engine block and cylinder head, the heat causes your head gasket to expand and this often leads to a blown head gasket.

How Can You Test for a Blown Head Gasket?

Testing for a blown head gasket allows for a better, accurate evaluation of your car. Here are four ways for you to test for a blown head gasket:

  • When your engine is cold, remove the oil filler cap and check for a coffee-colored liquid in and around the cap. If you notice this, it means the coolant has mixed with your oil showing that your head gasket has failed in keeping the liquids apart.
  • Remove your spark plugs and pressure the cooling system, then crank up your car engine as you inspect. If you notice coolant in one or more of your spark plug holes that starts spraying out, then you’ve got a blown head gasket on your hands.
  • When your head gasket fails, combustible gases easily enter your cooling system. This would show as air bubbles in your radiator [Be careful when checking this as the coolant could erupt violently from the radiator]. To check for bubbles, remove your radiator cap and warm up your car engine. If your head gasket is blown, you will quickly notice the bubbles in the tank.
  • Don’t stop your testing just yet. In most cases, the gasket could burn somewhere between two cylinders. So you’d need to conduct the compression test by removing all spark plugs and then manually thread the compression. Crank your car engine and observe the readings on your compression tester for each cylinder. If two side-by-side cylinders result in ‘0 psi’, then it’s bad news.

Can You Drive with a Blown Head Gasket?

If you’re asking this question, then it means you have a blown head gasket already. Will your car run with a blown head gasket? Yes, but poorly. Do we recommend driving your car with a blown head gasket? No! If the coolant hasn’t leaked enough already – to mix with the oil in your engine – and destroy the lower end then, driving your car with a blown head gasket will certainly lead to this. Some cars can sustain a blown head gasket for a couple of months while some would stop instantly. However, taking this risk is dangerous.