Cracked Head vs. Blown Head Gasket

Identifying a Blown Head Gasket & Cracked Head

A cracked engine head or a blown head gasket is enough to stop anyone in their tracks. While both engine issues are serious, a cracked head entails much more than a new gasket to fix. Knowing what problem you’re dealing with is key to getting your vehicle back on the road.

Signs of a Bad Head Gasket or Cracked Head

The symptoms of a cracked head and a leaking and damaged head gasket are similar. You may notice one or more of these symptoms:

• Engine overheating
• Low coolant levels
• White smoke coming from the tailpipe
• Bubbling in the radiator & coolant reservoir
• Unexplained coolant loss with no leaks
• Milky white coloration in the oil
• Misfires and rough running engine/flashing Check Engine light

Causes of a Blown Head Gasket or Cracked Head

The source of a blown head gasket or cracked head is usually from overheating. The weaker link of the two is the head gasket. In most cases, the head gasket fails before the head cracks, but sometimes both can happen. The source of the overheating can be a low coolant level due to hose failure, water pump failure or other gasket failure. A broken belt that causes the water pump to no longer to be driven, or an electric fan failure are other sources that can cause the engine to overheat.

Making a Diagnosis

Because the symptoms of a blown head gasket and a cracked head are similar, the only way to make a definitive diagnosis is to remove the head(s). Once the head(s) are removed, a visual inspection may reveal a cracked head but, in most cases, the head(s) will need to go to the machine shop for a pressure test to be performed to determine if the head(s) are cracked.

Once you have determined what the issue is, you can make an informed decision on what repairs to make. Although it is labor intensive, replacing a head gasket is a common repair that is cost effective. However, replacing a cracked head can be extremely expensive and it is worth taking time to assess if it makes sense to invest a large amount of money into the vehicle.

A severe engine overheat that caused a head to crack will require further investigation to make sure the lower end of the engine is in good enough condition to warrant replacement of the cylinder head. Also keep in mind that coolant passing out through the exhaust will require oxygen sensor replacement and possibly catalytic converter replacement.

The Fel-Pro® Advantage

Fel-Pro offers application-specific head gaskets that set the standard for sealing solutions. When you install a Fel-Pro gasket, you can be sure that you have selected a premium part for the repair job. Fel-Pro gaskets are engineered, tested and manufactured to deliver a reliable seal. This is why Fel-Pro has earned its reputation as The Gaskets Professionals Trust™.

Learn more about Fel-Pro quality gaskets that are specifically designed for the repair environment, find your car part, or find where to buy your auto part today.

The content in this article is for informational purposes only. You should consult with a certified technician or mechanic if you have questions relating to any of the topics covered herein. Tenneco will not be liable for any loss or damage caused by your reliance on any content.