7 Different Ways a Head Gasket Can Fail

Your car’s engine is a complex machine with many parts working together. One essential part is the head gasket, which acts like a seal between the engine block and the cylinder head. It keeps engine oil, coolant, and combustion pressure separate from each other.

But just like any other part, a head gasket can wear down and fail. When that happens, it can cause a variety of problems for your engine.

This guide by All Aspects Motors will explain the 7 most common ways a head gasket can fail and the warning signs you should watch out for.

What is a Head Gasket, and Why is it Important?

Your car engine has two key sections.

1. The engine block is the main body, where pistons move up and down.
2. The cylinder head sits on top, and it has valves that open and close to let air in and out.

But there’s a gap between these two parts. Now, between these two sections sits a thin, super-strong seal: the head gasket. It’s a special seal that plugs this gap tightly.

The head gasket is super important because it has 2 big jobs:

1. Keeps Engine Oil & Coolant Separate:

   The head gasket stops engine fluids, like oil and coolant, from mixing. Oil keeps parts moving smoothly, and coolant stops the engine from overheating.

2. Seals The Pressure:

   Your engine uses pressure from burning fuel to drive your car forward. The head gasket traps that pressure inside the cylinders to give your car power. Leaks can make your engine lose power and run poorly.

Read More: Head Gasket Repair: Indicators And Options

7 Ways a Head Gasket Can Fail

A failing head gasket can cause different problems depending on where it breaks. Here are the 7 most common types of failure and the signs to watch out for:

1. External Coolant Leak

Coolant is a special liquid that circulates within the engine and keeps it from overheating. The head gasket seals these channels, preventing coolant from escaping. When the gasket fails, cracks or develops holes, the coolant leaks externally. You will notice a drop in coolant level requiring frequent top-ups.

Signs to Watch Out For:

• Puddles of green or yellow liquid: You might see these under your car after parking.
• Rapidly dropping coolant level: Keep an eye on your coolant reservoir. If the level keeps going down without visible leaks, it is leaking internally.
• Engine overheating: Without enough coolant, your engine can’t stay cool, leading to overheating.

2. Compression Leak to Oil Galleries

The head gasket separates the high-pressure combustion chamber from the oil passages that lubricate the engine.

A failing gasket can allow compressed gases to leak past the seal and into the oil galleries. This can cause a rough idle, where the engine vibrates more than usual, and a potential drop in engine power.

Signs to Watch Out For:

• Rough idling and reduced power: Leaking compression disrupts the smooth operation of the engine.
• Thick, milky oil: Oil mixed with coolant creates a brown, sludgy mess that can clog vital engine parts.
• Engine overheating: Contaminated oil loses its ability to cool things down, increasing the risk of overheating.

Read More: How To Increase Engine Performance? 10 Ways To Maximise Car Engine Power

3. Water to Oil Leak

Similar to the previous scenario, a failing head gasket lets coolant (water) mix directly with engine oil. This creates the same problems as a compression leak into the oil, like milky white or brown sludge formation and overheating.

Signs to Watch Out For:

• Milky-looking oil on the dipstick: This is a clear sign of coolant mixing with oil.
• Overheating engine: Contaminated oil can’t keep things cool properly.
• Engine running rough: Leaking coolant and oil disrupt smooth engine operation.

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4. Compression Leak Between Cylinders

The head gasket also separates the cylinders in your engine. When the gasket fails between cylinders, the high-pressure combustion gases from one cylinder can leak into another. This disrupts the normal combustion process, leading to problems.

Signs to Watch Out For:

• Loss of power: Leaking gases reduce the pressure available to push the pistons down, causing decreased power.
• Rough idling and engine vibration: Leaking gases interfere with the smooth burning of fuel.
• Uneven engine performance: Different cylinders might not be working at their full potential.

5. External Compression Leak

The head gasket contains the high-pressure gases created during combustion. When the gasket fails between a cylinder and the outside world, these hot gases can leak out. It’s like a pressure cooker letting off steam – not in a good way.

Signs to Watch Out For:

• Loss of power: Leaking gases reduce the pressure pushing the pistons down.
• Unusual engine noises: Leaking gases can cause knocking or other abnormal sounds.
• White smoke from the exhaust: This smoke indicates coolant burning in the engine due to a leak between the coolant passages and the combustion chambers.

6. External Oil Leak

The head gasket also acts as a barrier between the engine oil passages and the outside. When the gasket weakens, oil can leak out, causing:

• Burning oil smell: Leaking oil can drip onto hot engine parts, burning off and creating a distinct burnt oil odour.
• Low oil levels: Just like a leaky bucket, a leaking head gasket will cause your engine oil level to drop steadily. This can lead to engine damage if not addressed quickly.

Read More: 10 Signs Your Car Needs Oil Change

7. Compression Leak to Coolant

The head gasket separates the coolant from the combustion chambers. Hot combustion gases leaking from the cylinders into the coolant passages due to a failing head gasket can cause the coolant to overheat and potentially blow a hose. Overheating is a major sign.

Signs to Watch Out For:

• Overheating engine: Leaking gases can pressurize the coolant system, reducing its ability to cool the engine.
• Rapidly dropping coolant level: Leaking gases can displace coolant, causing the level to drop quickly.
• Bubbles in the coolant reservoir: As combustion gases leak into the coolant, you might see bubbles forming in the reservoir.
• White smoke from the exhaust: Similar to a leak between coolant and cylinders, this smoke indicates coolant burning in the engine.

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Diagnosing a Head Gasket Problem

If you suspect a head gasket issue, don’t ignore it. Ignoring it can lead to severe engine damage and costly head gasket repairs. Here’s what you can do:

• Visual inspection: Look for external leaks of oil or coolant.
• Exhaust gas test: This test checks for the presence of combustion gases in the coolant.
• Coolant system pressure test: This test can identify leaks in the gasket or cooling system.

Remember: It’s always best to consult a certified mechanic for a professional diagnosis and repair.

Find a trusted mechanic in Perth to handle the job. Search online for “head gasket repair near me” and get quotes from local professionals to get your car back on the road quickly.

Read More: Searching For The Best Car Mechanics In Perth? Here Is Your Guide

Head Gasket Repair Cost

The cost of repairing a blown head gasket in Perth can vary depending on several factors:

• Estimated Cost: You can expect to pay anywhere between $1,000 and $3,200 or more for a head gasket repair in Perth.
• Local Labor rates: Mechanics in Perth typically charge between $40 and $120 per hour.
• Car Make & Model: The complexity of the engine and the specific car make and model will also influence the cost. For instance, a head gasket repair for a Nissan in Perth might be around $1,200, while a Subaru repair could be slightly higher at $1,400 on average.

Read More: Car Service Vs Car Repairs | What’s The Difference?

All Aspects Motors: Your Partner in Engine Health

If you suspect a head gasket issue. Bring your car to All Aspects Motors for a professional diagnosis. Our experienced mechanics will quickly identify the problem and get you back on the road safely

Remember, early detection is key to preventing costly repairs.

Click Here to Schedule Your Head Gasket Diagnosis