Clogged Radiator or Blown Head Gasket: How to Tell the Difference

If your car is experiencing overheating or poor engine performance, it can be hard to tell whether the issue is related to a clogged radiator or a blown head gasket.

A good way to tell the difference between a clogged radiator or blown head gasket is by checking the engine oil filler cap. If it looks milky and frothy it’s likely to be the head gasket.

In this article, we’ll discuss the signs of a clogged radiator and blown head gasket, and how to tell the difference between them.

Signs of a Clogged Radiator

Below are common signs of a clogged radiator.

1. Overheating
2. Coolant leaking
3. Discoloured coolant

1. Overheating or high coolant temperature

An obvious sign of a clogged radiator is a high coolant temperature or the engine overheating.

This issue could be caused by a buildup of debris or corrosion within the radiator, preventing proper heat dissipation and coolant liquid flow.

2. Coolant leaking

Coolant leaking from the cooling system is another sign of a clogged radiator.

A leak could be caused by a crack or hole in the radiator or damage to the hoses or fittings, the higher pressure caused by the radiator blockage can cause these coolant leaks.

4. Discoloured coolant

Discoloured coolant liquid could be an indication that the radiator is clogged. It should be a clear colour, not cloudy or discoloured.

If the coolant liquid appears brown or rusty, it may be a sign of debris or rust that has built up inside the radiator.

Signs of a Blown Head Gasket

Below are common signs of a blown head gasket.

1. Milky looking engine oil
2. White exhaust smoke
3. Reduced performance
4. Rough idle

1. Milky looking engine oil

A blown head gasket can cause the engine oil to become contaminated, leading to a milky or frothy appearance of the oil filler cap.

This is usually because coolant is leaking into the engine oil and mixing with it.

This contamination can reduce the effectiveness of the oil and cause damage to the bearings, cylinder walls, and other engine parts.

2. White smoke from exhaust

White smoke coming from the exhaust is an indicator of a blown head gasket, it’s caused by coolant leaking into the combustion chamber and being burned.

The smoke will be white due to the high water content in the coolant.

3. Poor engine performance

A damaged head gasket can lead to poor engine performance, usually because the engine may not be able to create enough compression.

Loss of compression can reduce an engine’s efficiency and power output, leading to reduced acceleration, sluggishness, and worse fuel economy.

4. Rough idle

A rough idle is also a sign of a blown head gasket.

The compression in the engine may not be consistent across all cylinders, causing an imbalance in the engine’s combustion process, leading to a rough and unstable idle.

An engine may also stall or misfire.

How to Tell the Difference

If you’re experiencing one or more of the signs listed above, it can be hard to tell whether the issue is related to a clogged radiator or a blown head gasket.

One way to know is to check the engine oil filler cap. If the oil filler cap looks milky and frothy, it’s likely to be a blown head gasket.

What Can Be Mistaken for a Blown Head Gasket?

There are several other issues that can also be mistaken for a blown head gasket, including the following.

• Cracked cylinder head
• Cracked engine block
• Cracked cylinder liner
• Leaking intake manifold gasket

These issues can cause similar symptoms, such as coolant leaks, poor engine performance, overheating, etc.

Conclusion

Both a clogged radiator and a blown head gasket have similar signs and symptoms, making it hard to tell which is the issue.

Checking the oil filler cap to see if its milky and frothy is the best way to determine what the issue is.