What Causes a Blown Head Gasket?

A blown head gasket is a major pain. At the very least, a leak in your head gasket means your vehicle is off the road for repairs, and in the worst cases, your engine can suffer major damage and you could wind up scrapping the car. It’s important to understand what can cause a blown head gasket, so you can be aware of the symptoms and react before it’s too late.


When you react in time with help from Bar’s Leaks head gasket repair products, you can avoid costly and time-consuming physical repairs.

The Causes

To start, you need to be able to recognize the signs of a blown head gasket. Your head gasket is a metallic seal that is sandwiched between your engine block and your engine’s head. It keeps your engine’s fluids from leaking and is put under enormous stress during engine operation, thanks to a combination of factors:

  • Mechanical Forces: The nature of the detonations in your engine creates huge amounts of energy, or pressure, every time your cylinders fire. Over time, these forces stress your head gasket and can eventually lead to cracks and leaks.
  • Heat: Your engine creates large amounts of heat under operation. A difference in thermal expansion rates between your block and head mean the head gasket in-between is subjected to high thermal and mechanical stresses that slowly wear the gasket down.
  • Vibration: Vibration: Natural vibrations from your engine and those created as you drive down the road also fatigue your head gasket over time. Your head bolts, which keep the head gasket sandwiched between the block and head, can start to stretch (and possibly warp) to allow increased friction and vibration wear.
  • Overheating: Allowing your coolant level to run low can cause damage to your head gasket. When coolant isn’t available to pull engine heat from your block and heads, the extra heat can cause expansion on your head gasket, which often results in a blown head gasket.

These forces can wear your head gasket out over time and cause it to fail. Once your gasket cracks, engine coolant can leak out of your engine, allowing overheating and major engine damage.

The Symptoms

There are several obvious symptoms of a blown head gasket, and it’s important to know them. When you detect them early on you can correct the problem before it becomes a major one:

  • A strong, sharp smell of heated coolant
  • Low coolant level in your coolant reservoir
  • Reduced power or problems with idling and acceleration

In all cases, the key to repairing a blown head gasket without spending a fortune is reacting as soon as you notice something is wrong. If you drive too long with a blown head gasket, you can cause major damage — like a cracked head or block and piston failure — that can only be fixed with an expensive engine rebuild. In the case of older cars, the cost of a physical head gasket replacement or engine rebuild often doesn’t make sense, putting your vehicle off the road permanently.

Save time, money and energy by using a bottle of Bar’s Leaks Head Seal Blown Head Gasket Repair (HG-1). You can also check out our other head gasket repair products. Our solutions are permanent, and they will give you many more miles of driving without the cost and hassle of a head gasket repair. We’re the ones who created the entire chemical head gasket repair category of products, and we’ve sold over 5M bottles since we introduced this chemical technology. It’s safe to say we know a thing or two about head gasket repairs.

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