What is a cracked cylinder head, the symptoms and how to repair it

A cracked or damaged cylinder head can result in severe damage to the entire engine. K-Seal will permanently repair most cylinder head cracks or leaks without the high costs. Just shake, pour, and go!

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What is a cylinder head?

A cylinder head sits on top of the engine block and covers its cylinders, thus creating the combustion chamber. The cylinder head creates the space for the passages that feed air and fuel to the cylinders and is sealed in place by the head gasket.

Cylinder Head
Cylinder Head

Due to constantly changing temperatures and high-pressure levels, the head has to be robust enough to withstand the demands placed on it without cracking or breaking. It is a complicated and vital part of the engine and vehicle as a whole, meaning that any problem it might develop should be repaired as quickly as possible.

How does a cylinder head work?

The cylinder head allows the engine to perform at maximum capacity by connecting to the intake and exhaust manifolds to allow the quick burn of fuel and air that moves the engine’s pistons. 

The intake manifold feeds air into the head, where it is combusted with fuel to produce exhaust gasses, which are expelled through the exhaust manifold. It’s important that the intake and exhaust valves, which allow the entry and exit of relevant gasses, open and close at the correct times to keep the engine running smoothly.

Why do cylinder heads fail?

The most common reasons for cylinder head failure include:

  • Overheating: from factors like coolant loss, head gasket failure, or restricted coolant flow.
  • Warping: Cylinder heads may warp due to pressure from extreme temperature changes. Warping creates an uneven surface, meaning that the head gasket is no longer held in the right position.

Warping is a particular problem for cylinder heads made of aluminum. Different engines have different levels of tolerance for cylinder head warping – some can withstand a high amount of warping while still working effectively. If your cylinder head does warp, you may be able to take it to a mechanic who specializes in realigning them – if not, you will probably need a replacement.

In extreme cases, a cracked or damaged cylinder head can result in terminal damage to the entire engine! Learning to recognize the symptoms & understanding the fix can help avoid these costs.

What are the symptoms of a cracked cylinder head?

The symptoms of a cracked cylinder head are varied – drivers must be able to recognize them as quickly as possible so any damage can be limited. If the cylinder head fails, it will lead to the engine (and by extension the vehicle) breaking down.

  • Drop in coolant levels
  • Drop in oil levels
  • Drop in engine performance
  • Engine overheating
  • Rough running and misfiring
  • White smoke coming out of the exhaust

How much will a cylinder head repair cost at a workshop?

A good mechanic should be able to repair and recondition a cylinder head from as little as $90, but it can also cost hundreds of dollars to do the same job. 

The cost of a cylinder head repair will depend on the value of the cylinder head and the price you are quoted to repair it if it develops a crack or stops working as effectively as it should. In many cases, it may be worth simply buying a new one. Before this though, you should see if K-Seal can help.

Can K-Seal fix my cylinder head?

K-Seal will permanently repair most cracks or leaks in the cylinder head where there is coolant loss. You simply shake the bottle, pour and go!

Want to get hold of a bottle to fix your cracked cylinder head? Use our simple stockist search and get back on the road quickly.

K-Seal being poured into a car to fix a cracked Cylinder Head.

Could other parts of my engine be affected?

Your cylinder head isn’t the only part of your engine that might be suffering. Select an engine part in the interactive diagram below to explore your engine and the important components that keep everything ticking over.

Click on the engine components below for details
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