What Causes a Head Gasket to Blow?

“What Causes a Head Gasket to Blow?” Welcome to Mercie J Auto Care, Where Compassion and Craftsmanship Come Together. I'm Rick Smith, ASE Certified Master Technician. The head gasket is between the engine block and the cylinder head. Those two large metal assemblies expand and contract at different rates with changes in temperature. Because of the expansion and contraction, the head gasket is constantly moving. Over time, it can wear, but most often if fails due to stress from overheating. When the engine is overheated, the gasket can become compressed to the point that is cannot return to and elastic state. Making sure we don’t allow the engine to overheat from any leaks, or a fan issue is the best way to protect the head gasket. It can also rot away if the coolant (aka anti-freeze or radiator fluid) is deteriorated so changing that fluid regularly is great protection as well.