8 Symptoms of a Blown Head Gasket and a Cracked Engine Block
The two main parts of an engine are the cylinder head and the engine block. The block contains the pistons and cylinders, and the cylinder head contains the rocker arms and valves. The cylinder head gasket sits between the block and the cylinder head. This gasket acts as a seal for all the cylinders in the block. The seal prevents coolant from leaking out of the cylinders and also prevents oil from leaking into the cylinders and mixing with the coolant.
Most importantly, if there is a problem with the engine block or cylinder head, a mechanic can use the gasket to separate these two large engine parts and repair them separately. If you think you have a blown head gasket, you may actually have a cracked engine block and vice versa. The symptoms may be similar.
3 Symptoms of a Blown Head Gasket
Cylinder head gaskets are bound to burst after a while. This can cause engine oil, fuel and/or coolant to mix with each other in the combustion chamber. Below are the three most common signs of a blown head gasket:
1) Antifreeze and oil mixture
A blown head gasket can cause the oil to mix with the antifreeze. However, if the engine block is cracked, that can also happen, so there should be other symptoms present.
2) Engine overheating
When coolant gets into the oil, it can no longer do its job of properly cooling the engine components. This causes the engine to overheat. If your car overheats, your best bet is to pull over to the side of the road and stop driving.
3) Poor Engine Performance
When your engine overheats, you will experience a significant loss in performance. The biggest issues are slow acceleration and engine stalling. If that’s the case, you’re probably experiencing low engine compression.
5 Symptoms of a Cracked Engine Block
The engine block houses and protects the cylinders of your engine. The engine block housing is lubricated to prevent the cylinders and the components inside the cylinders from overheating.
The cylinder head sits on top of the engine block. It closes off the cylinders from above to form the combustion chamber. It’s relatively rare for an engine block to crack, but it has happened before.
When this happens, your engine will start to have all sorts of problems and will exhibit some very bad symptoms. When the engine block can no longer protect the internal components from excessive heat or cold, the entire engine will literally fail. Here are 5 common signs to expect from a cracked engine block:
1) Oil and antifreeze mixture
If your engine block has a significant crack, the engine oil and antifreeze can mix. Antifreeze can get in through the crack and circulate along with the oil. This means big problems for your engine. As mentioned above, oil and antifreeze mixing can indicate a blown head gasket, so keep an eye out for other symptoms too.
2) Engine Smoke
The obvious symptom of a cracked block is that the engine will smoke. Ignoring this for long periods of time can lead to further engine problems. Smoke is caused by exhaust gases leaking out of the exhaust pipe through the crack instead of into the exhaust system. Additionally, you may notice a significant loss of power when accelerating.
3) You see a crack in the block
Of course, it’s usually not as easy as opening the hood. If you don’t have any mechanical experience, hire a mechanic to diagnose it for you so you can be confident in your diagnosis.
4) Engine overheating
The engine block housing helps keep engine components cool and lubricated. If the block is cracked, the engine can overheat if it continues to run without being adequately cooled, eventually causing internal damage.
5) Low Compression
The combustion process causes the engine to compress. Since combustion occurs within the engine block, any cracks in the block will allow air to escape and reduce compression. As soon as this happens, your engine will lose performance.