Last Updated on July 5, 2021
Cylinder heads are located on top of the cylinders that are inside an internal combustion engine. The pistons close the heads on top of the cylinders, creating a combustion chamber that compresses the contents of the cylinder.
Cylinder heads obviously provide an important role in the combustion process, but what many people don’t realize is they have a very lightweight design and construction to them.
This causes them to start cracking after about five years of use in some cases, especially if they are aluminum overhead cam heads. But if you have cast iron heads then cracks will form eventually.
But one issue is the culprit in the majority of cracked cylinder heads. Keep reading to see what causes this and how much it will cost to repair.
Common Causes of Cylinder Head Cracks
An overheated engine is the most common cause of a cracked cylinder head as components of the motor get stressed beyond their designed limits.
A big reason why cracks form on the cylinder heads is because the valve seats become hardened from the concentrated heating process. This ends up putting more stress on the cylinder heads, causing small cracks to form over time.
The engine doesn’t always have to be overheated for this to happen either. All it takes is for the valve seats to be put under stressful conditions for the cracks to start forming on the heads.
Cracked Head Repair Cost
The cost to repair a cracked cylinder varies between different model cars. The minimum cost you can expect to pay is $500, but with parts and labor costs it could easily go to $1,000. Then depending on your make, model, seriousness, and where you take your vehicles for repairs, it may cost you $2,000 or even more.
If your car is still under warranty then you should be able to get these costs covered by your dealer. Sometimes new cars will be sold with engines that have a mixture of metals inside of them. For example, a car might have a solid cast iron engine block that will make it appear to be strong.
But what you won’t know right away is the cylinder head is made of aluminum and not iron. This increases the chances of weak spots forming in the metal and the engine’s components being incorrectly installed. Once this happens, the cylinder heads will start to crack right away even if the car is new.
The best way to preserve the life of your cylinder heads is to keep your radiator filled and make sure you have no leaky hoses or stretched belts.
If your car ever overheats then you may need to have your head gasket replaced and the heads checked for cracks. Your mechanic will be able to make the best recommendation at that point as to whether you need to replace the cylinder heads or not.