can a bad thermostat cause a blown head gasket

Can A Bad Thermostat Cause A Blown Head Gasket?


August 10, 2022

Can a bad thermostat cause a blown head gasket?

Can you think of anything more terrifying than a head gasket bursting?

When you replace a part that costs around $30 or less, it necessitates a complete engine rebuild.

However, the labor charge is approximately $1200 and might be higher depending on the extent of the damage.

In light of this, people frequently inquire, “What causes a blown head gasket?”

Although a head gasket should ideally survive for more than ten years, it is not the same with every car or at any one moment.

There are a variety of reasons why it might fail, including erosion and wear and tear.

  • Overheated engine
  • Abnormal combustion
  • Design issues
  • Poor installation

Although you just discovered a blown head gasket, it is possible that the problem has been there for some time.

The head gasket, while being a robust part, has been absorbing pressure for some time.

As a result, if your head gasket is causing problems, it’s high time you investigated the reason behind it.

Head Gasket: The Important Seal In The Car

Before you learn about the origins of a head gasket failure, you should understand what a head gasket is and why it causes so much worry to motorists.

The engine block and cylinder head are two components that constitute every automobile’s engine.

The head gasket, for example, is the space between the two.

The cylinder block and pistons are on one side, and the valves, camshafts, and spark plugs are on the other.

The head gasket is a seal that blocks the engine oil and coolant from entering the combustion chamber.

can a bad thermostat cause a blown head gasket

The head gasket is one of the most important seals in your car because it keeps other fluids from entering the cylinders.

It should ideally be constructed of steel or copper.

It withstood the strain caused by the planes’ twisting, stretching, compressing, and rubbing.

There are a variety of reasons why the head gasket is such an essential component of an engine.

  • Because it maintains a high pressure in the combustion chamber, the valve check is essential for preventing power loss. The piston’s need for maximum pressure to operate correctly explains why this is important.
  • Although the head gasket is essentially a seal, it does serve as a conduit for the coolant and engine oil. It also keeps them apart to prevent the two liquids from combining. Since they have varied responsibilities, it’s critical that they don’t mix.

The head gasket is responsible for the proper functioning of an engine.

When it develops a leak and fails, it is considered blown.

You may repair a little leak with a sealant if you notice it early enough, or you may need to replace the component.

The actual work involved in replacing the part isn’t too difficult; all you have to do is mantle the engine.

The thing about the gasket is that if you catch the problem early enough, you should be fine.

As a result, make it a must to understand the issues at hand and attempt to avoid them if feasible.

Why Is Your Head Gasket Fails? Find The Symptoms Of The Blow Head Gasket!

It’s critical to understand the reasons for head gasket failure since the head gasket is such an essential component of an engine.

Being informed about the causes and symptoms is a must for every car owner, particularly if your vehicle is older.

1. Overheating Of Engine 

An engine that is overheated is the most common cause of head gasket failure.

It occurs when the gasket is subjected to heat not crafted to handle it.

During its operation, an engine creates a lot of heat.

When the metal grows too hot, it can expand and collapse the head gasket beyond its capacity, resulting in a leak.

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At this time, the gasket no longer seals properly since it no longer fits as snugly as previously.

The head gasket between the engine head and cylinders takes the brunt of the punishment if they’re made of different metals with varying thermal expansion rates.

Even though it doesn’t happen immediately, the high thermal stress can wear down your engine slowly.

Following are some of the reasons why your car’s engine overheats.

  • A leak in a cooling system
  • Defective radiator fan
  • Congested radiator
  • Stuck thermostat
  • Faulty water pump
  • Wrong coolant
  • Old coolant in a system
  • Bad radiator cap
  • An improper mixture of antifreeze and water
  • Lack of maintenance

2. Abnormal Combustion

A blown head gasket is caused by combustion problems as much as overheating.

It might be detonation or preignition issues with the engine.

Both trigger a sharp increase in pressure, which can cause the gasket to deteriorate over time.

The air-fuel mixture in a conventional combustion situation burns equally, but this isn’t the case in an abnormal combustion environment.

A too-thin mix or low-octane gasoline can cause the process to be interrupted, resulting in an abnormality.


The ignition procedure might sometimes be slowed down in the cylinder.

This allows for a lot of pressure to build up, resulting in a second ignition at the end of the mix.

Both ignitions collide, generating a knocking noise.

The explosion’s shockwave produces internal shaking, which damages the engine and head gasket as well.

Here are some reasons why your engine may develop detonation.

  • Too thin air and fuel mixture
  • Fast ignition timing
  • Improper fuel distribution in the cylinder
  • Broken EGR valve
  • Low octane fuel


Preignition, on the other hand, occurs when the combustion begins before the spark plug sparks.

This also results in two ignition events, but this time they merge to produce a pinging sound, which is a mild form of knocking.

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A pinging sound is produced by the engine as a result of preignition.

Although not as damaging as detonation pinging, which can lead to damage to the engine, it is nevertheless unpleasant.

Here are some causes for preignition.

  • Accumulation of carbon in the chamber
  • The overheated exhaust valve and metal edge
  • Bright spark plug
  • Issues in the cooling system
  • Not enough lubrication in the engine

3. Hot Spots

Because of the numerous gasket types, there may be hotspots.

Not just because of replacement gaskets, which have blown due to hotspots.

Some engines include close exhaust ports, which is not desirable.

Hot spots can occur in these locations as a result of this.

If the gaskets in these areas include reinforcement, heat will dissipate; however, if the gasket cannot cope with difficulties in this area, failure may occur.

Gaskets must fill in the gaps on their surfaces.

Some gaskets are built with such a design that they fill in the gaps left by filing.

These can tolerate high temperatures caused by incorrect ignition, overheating, and other issues.

If you reface your engine block or cylinder head, make sure to buy a gasket that fits properly.

4. Incorrect Head Bolt Torque

All of the bolts should be torqued to the same level.

Unbalanced torque can cause uneven clamping strain on the head gasket.

Unbalanced loads put pressure on particular regions of the head gasket, causing it to leak.

When these locations are exposed to high heat or pressure, they inflate, allowing for leaks.

If you replace the head bolts frequently, you can prevent gasket failure.

Also, make sure to use a torque wrench to tighten the head bolts.

It must be set correctly and installed in a specified manner and at precise intervals as described in the instructions.

5. Incorrect Installation And Bad Head Gasket 

Low-quality head gaskets might have manufacturing flaws or fail to meet engine standards.

A high-quality head gasket, on the other hand, can break if installed incorrectly.

Aside from changing a head gasket, you should take a few more measures.

  • Do not reuse old or damaged head bolts
  • When tightening the head bolts, use the incorrect sequence
  • To clean the head/block-mating surface, don’t use scratchy scrubbers.
  • Use the correct sealant
  • When installing a new gasket, make sure to remove the dirty regions.

The head bolts that hold the gasket in place are just as essential as the gasket itself.

The gasket’s stability can be jeopardized by a damaged thread, which will eventually cause it to fail.

Furthermore, the bolt must be in good working order to retain the seal.

Corrosion, grime, rust, and slices might weaken the bolt’s performance.

6. Engine Surface Finish

Before replacing the head gasket, your mechanic would most likely resurface the cylinder head and engine block.

The surface must be flat and smooth for a successful installation.

Corrosion on the gasket is more likely to wear it down faster than anticipated, which is true for both cast-iron and composite metal engines.

Rubber gaskets are a good alternative if resurfacing isn’t an option.

They can also handle rough exteriors better than metal ones because they can endure heat as well as force.

7. Lack Of Coolant

On a daily basis, most vehicles have enough cooling system capacity.

It has adequate coolant to keep the engine cool on a day-to-day basis, but if the engine overheats, it may not be able to handle it.

The same can be said for a filthy cooling system or a faulty cooling fan.

You should also inspect the proportion of anti-freeze to coolant in your system.

There is no need for excessive amounts of the latter.

If you suspect an overheating engine, make it a point to keep an eye on the coolant levels in your automobile.

You may also clean out the cooling system on a regular basis to ensure that it is functioning properly.

A happy head gasket results from an effective cooling system, and everything operates as expected and in the correct sequence.

8. Choice Of Head Gasket Material

Gaskets come in a variety of materials, including graphite, copper, rubber, composite, and MLS-multi-layered steel.

The gasket should be chosen based on the engine block’s and cylinder head’s composition as well as their make.

  • Rubber: It is well-known and favored for its adaptability. It’s also flame-resistant, simple to set up, and cost-effective.
  • Composite: The composite gaskets are still available. It’s resistant to alcohol, gasoline coolant, and oil because of the asbestos and graphite mix. Unfortunately, asbestos sickness is a genuine phenomenon.
  • Copper: The more costly of the two due to materials expenditures, the copper gasket reduces warping and distributes heat equally.
  • Multi-layered Steel: It’s the most well-known, and it’s been in every vehicle since then because it is distortion-proof. They are constructed of many steel layers that fit the surface on which they rest.

Frequently Asked Questions

What Should I Do If My Head Gasket Is Blown?

A blown head gasket is not readily visible to the naked eye, although it may be detected by a series of engine signs.

The following are some of the most frequent indicators of a head gasket:

  • Engine overheating
  • Coolant leaking externally
  • White smoke from the exhaust pipe
  • Low coolant levels
  • Bubble in the radiator

Can A Bad Thermostat Cause The Blown Head Gasket?

Thermostats that are stuck in the closed position can’t send coolant to the cooling system, resulting in an overheated engine.

An overheated engine might cause the cylinder head to distort and leak the gasket.

Can The Car Still Run With The Blown Head Gasket?

A blown head gasket is possible in a vehicle, but it is not recommended.

Even at full throttle, you can notice a significant loss of power.

The coolant and oil are allowed to mix with the gases, which are not good for the engine.

Because the cylinders might be deformed as a result of this event, it isn’t ideal for the engine.


A blown head gasket is a major problem in a car since it allows fluids to mix and flow into areas where they are not allowed.

It may also cost thousands of dollars to repair.

As a result, you must understand what a head gasket is and how it works.

The head gasket may develop leaks owing to substandard installation, faulty bolts, or even the engine surface finish.

The head gaskets can disrupt due to a variety of causes, including overheating engines and combustion problems.


Jeffrey Bryce is an experienced motorcycle rider with years of experience caring for motorcycles. His natural fondness for motorcycles have made him come up with, which is dedicated to answering and teaching you how to care for your bike with the care it requires. LetsGoForARide is the one of his important lifework in reaching out to communities of motorcycle enthusiasts on how to take care of their bike and choosing the correct spare part.