What Causes Head Gaskets To Blow | Sun Devil Auto

Did You Blow A Gasket?

When you hear the expression “blow a gasket” this usually indicates a furious reaction, to the point of losing control of behavior. While not quite a shocking behavior, when your vehicle’s engine blows a gasket, it’s bad news for the engine. There are several indicators that your vehicle has blown a gasket that includes overheating, tailpipe expelling smoke, poor performance, oil sludge, and fluid leaks. Located between the engine block and the cylinder head, you’ll find the head gasket. Read on to find out how each component works together and how to tell when the gasket has failed.

The Engine Block

overheated car engine The engine block is the main part of the engine. In newer vehicles, the engine block is made of an aluminum alloy whereas in older vehicles it was made of cast iron. In most aluminum blocks, either an iron sleeve will be pressed into the aluminum piston bores or a special hard plating is applied after the bores have been machined. The engine block, especially where the pistons are located, needs to be solid and resilient. This is because it houses the connecting rods which attach the pistons to the crankshaft necessary to make the crankshaft turn and, in some cases, the camshaft. The engine block is able to stay cool because of its system of passages that circulate engine coolant throughout, allowing heat from the combustion process to dissipate via the cooling system. Engine oil also passes through the engine block to keep the engine lubricated, ensuring proper working order.

The Cylinder Head

The pistons in the engine are constantly moving up and down. The pistons move up in order to compress the fuel/oxygen combination and back down because of the explosion by the fuel caused by the spark from the spark plugs. This combustion process is how the pistons turn the crankshaft, which ultimately sends power to move the wheels. The cylinder is the combustion chamber and is what the piston compresses the mixture to, above the pistons. In short, the cylinder head is essentially the cap of the engine block and the head gasket, when placed properly, is the seal between the two.

The Head Gasket

Located between the engine block and the cylinder head, the gasket’s job is to seal the internal combustion process to allow coolant and oil to travel through the head, to cool and lubricate the engine. It also seals the combustion chamber in the engine, which allows the vehicle to produce the proper amount of compression to move. Additionally, the head gasket is tasked with preventing gases from escaping from the combustion chamber, forcing them out the exhaust system.

Because its main job is to act as a seal, the general assumption is that a head gasket is made up of rubber or similar material, however, most modern engines use a multi-layer material made of steel interweaved with an elastomer, resulting in a stronger and longer lasting gasket. In the areas where the gasket meets the two major components, there is a silicone, or Viton, a rubber-like coating, material. In older vehicles, the gasket was composed of a composite made from graphite or asbestos. Because of its health risks, these types of gaskets were removed from production and are often very difficult to find. Compared to the strength of today’s gaskets, composite and shim type gaskets were more vulnerable and prone to leakage.

Signs the Gasket Has Blown

The engine requires three main fluids in order to operate: fuel, coolant, and engine oil. When the gasket leaks or blows, one or all fluids may leak out of or into the combustion chamber.

  • Smoke – A white cloud of smoke emerging from the tailpipe is most often caused by coolant that has entered the chamber. In addition, blue or grey smoke may indicate that oil has entered the chamber.
  • Overheating – When exhaust gases or hydrocarbons enter the cooling system, it is highly likely the vehicle will exhibit an overheating issue. Allowing the engine to overheat may warp the cylinder head where the gasket aligns, allowing the gasket to leak fluids or blow.
  • Poor Combustion – If the gasket has failed near the piston, the piston will fail to produce the proper amount of compression resulting in combustion difficulties. Because the engine is running on one less chamber, the reduced combustion can cause engine inefficiency reducing the amount of power or a reduction in fuel efficiency.

If you notice any signs such as poor gas mileage, low coolant levels, and overheating, this could be a result of a blown gasket, requiring an inspection by a professional. The Technicians at Sun Devil Auto are the professionals you can turn to when your engine displays any signs of distress. Our experts provide quality repairs that you can trust. Plus, we understand the inconvenience of being without a vehicle for any length of time and work quickly to get you back on the road and, in some cases the same day! We offer free towing with major repairs and a courtesy shuttle for your convenience. You don’t need to go to the dealership to find competitive prices, manufacturer equivalent parts, and exceptional service when you can choose Sun Devil Auto, your dealership alternative! Find a location near you to schedule an appointment for your engine diagnosis today.