Cracked Head Gasket Symptoms and Signs

If the engine head gasket of your car develops a problem, it could lead to extensive damage to the engine if you do not address it immediately. To help you avoid such a problem, I will discuss cracked head gasket symptoms and signs in this article.

Several signs can be attributed to a cracked head gasket. One of them is the engine overheating just a few minutes after it starts. Another is coolant leaks below the head gasket. White smoke coming from the exhaust or clouds of exhaust fumes during idling is another sign. Another symptom is bubbles in the radiator and reservoir overflow.

When the head gasket fails, the compressed mixture of air and fuel is allowed to escape. If that happens, there will be lesser compression inside the cylinders. With this loss of compression, the engine’s idling will be rough, resulting in a drastic power reduction. 

Read on to learn more about the symptoms and signs of a cracked head gasket.

Cracked Head Gasket Symptoms and Signs

cracked head gasket

Here are the cracked head gasket signs and symptoms:

  1. Engine overheats
  2. Coolant leaks or low coolant level
  3. White smoke coming out of the tailpipe or clouds of exhaust fumes
  4. Rough idling of the engine or sometimes engine knock
  5. Contaminated or milky discoloration of the engine oil
  6. The vehicle won’t start
  7. Bubbles form in the radiator, and the reservoir overflow
  8. Misfiring

1. Overheating Engine

An overheating engine is the most common symptom of a problematic head gasket. If it goes bad, the engine is forced to work harder to deliver the power as usual. In addition, when the head gasket has cracked, there’ll be some amount of coolant that will be lost in the system.

That will result in the cooling system’s weak performance, causing the engine to overheat even more. Thankfully, before the problem worsens, you will be given an early warning in the form of this symptom. More severe issues will ensue if you don’t correct the problem immediately.

If the head gasket issue happens between the combustion chamber and the cooling system, the symptom will be an overheating engine and coolant loss. Be observant, especially if your engine overheats just minutes after you start the engine.

The more severe symptom is engine overheating because if you don’t fix the problem immediately, it could lead to more severe damage, not only to your engine but also to the other critical components of your car.

2. Low Coolant Level

As I’ve already mentioned, if the point of failure of the head gasket is in between a combustion chamber and a coolant channel, your engine will consume more coolant than it usually does. If that happens, it could also result in an overheating engine simply because of the lack of coolant.

Thankfully, this symptom is the easiest one you can be sure of. If you see the presence of coolant leaks along the surface of the head gasket, you can be sure that it has blown.

That’s because coolant leaks, in most cases, occur between any of the engine’s cooling components and the combustion chamber.

3. White Smoke Coming from the Tailpipe

Most engine coolants are made up of water with special compounds that enhance their cooling power. Remember, the coolant is there to cool the engine. Meaning it just hovers outside the engine, not inside it.

So, when you see white smoke from your tailpipe, it is burned inside the engine, where it should not be. You see, water, when heated up, turns to vapor. And that’s the white smoke you see from your exhaust pipe.

Why is the coolant entering the combustion chambers, which it should not do? It can only do this because of a leaking head gasket. Any head gasket leak will allow the coolant to enter the engine’s insides.

White Smoke On Startup Then Disappears – Causes

4. Rough Idling or Engine Knock

In the matter of cracked head gaskets, one problem leads to another. When there’s a head gasket leak, one of the consequences is loose compression of the engine. Loose engine compression will lead to rough engine idling, engine knocking, and even stalling.

5. Contaminated Engine Oil

The engine oil can be contaminated by other substances if there is a leak somewhere in its structure. One of the usual suspects for this problem is a cracked head gasket. If it has blown, it can allow the mixing of the engine coolant with the engine oil.

If the coolant and engine oil mix, it will produce a frothy substance. This mixture will then collect under the oil filler cap of the engine. So, if you suspect that your engine oil is already contaminated, inspect this filler cap and look at its underside.

If there’s a buildup of this foamy substance under the cap, your engine oil is already contaminated. So, you can use this knowledge to check if your head gasket is cracked or blown.

6. Vehicle Won’t Start

If your car’s head gasket is failing, it may even cause your car not to start. So, if you notice that the engine turns over every time you turn the ignition key but won’t start, it could be a cracked head gasket.

If you try to crank the engine again and it still won’t start, you are depleting the juices of the battery. So, even if you can turn on the starter, the spark plugs inside the engine won’t give the sparks needed by the fuel and air mixture to ignite. You will still have an engine that refuses to start.

7. Misfiring Engine

If the head gasket has failed, it will no longer be able to seal off the coolant passages from the engine’s cylinders. Consequently, the coolant will be able to enter the combustion chamber. It will skew the air-to-fuel ratio inside the engine. The result will be a misfiring engine.

What Is a Head Gasket and What Does It Do?

cracked head gasket symptoms

Prevents Intermixing of the Engine’s Fluids

Most modern engines are equipped with four-stroke Internal Combustion Engines (ICE). These engines use three fluid types: fuel, motor oil, and water/glycol coolant.

These fluids are not allowed to mix, or there will be a problem. To ensure they do not, that’s the work of the head gasket. It routes these fluids between the engine’s components so there will be no intermixing.

Designed with Many Holes

The head gasket is designed with many holes or rings for the said purpose. You can locate it between the engine block and the cylinder head. This gasket is a barrier to prevent engine fluids from going inside the cylinders.

Plays a Crucial Role in the Combustion Chamber

In other words, this gasket plays a crucial role in the combustion chamber. Aside from acting as a barrier to the cylinders, it also blocks off tubes to water and oil. Additionally, the head gasket faces a full range of temperatures since it is located between the cold and hot components of the engine.

Extreme Temperatures Can Damage the Head Gasket

Over time the extreme temperatures take their toll on the head gasket. Eventually, it will fail. But before it completely fails, it will show some signs of weaknesses. The problem is: that you can’t visually inspect the head gasket because of its obscure placement in the engine.

Examing a Head Gasket Requires Disassembling the Engine

If you want to examine it, you have to disassemble the engine first. This makes diagnosing the condition of a head gasket an impossible task. You are left with examining the signs and symptoms that may tell you if it’s having a problem.

Again, what are the symptoms of a cracked head gasket? A cracked head gasket can cause the engine to lose compression, stall, rough idle, or knock. But note that other issues can cause the engine to knock or run roughly.

What Are the Causes of Head Gasket Failure?

Generally, head gaskets are robust. They are built to withstand extreme temperature changes to last long. However, if there are causes that can make them fail, they will. What causes a cracked head gasket?

Here are some of the reasons:

1. Engine Overheating

An engine that gets too hot will affect the material of the head gasket. If that happens often, you can be sure that the head gasket will be badly affected.

Extreme heat will cause warping and cracking of the head gasket material. When that happens, the head gasket will not be able to provide the perfect sealing it should give to the engine.

2. Old Age

Gaskets are not indestructible. As they age, they wear out. So, if your car has seen hundreds of thousands of miles, and its gasket has never been replaced, it may develop issues.

The materials it is made of have already seen better days. That’s why car manufacturers recommend the replacement of the head gasket once a car has reached a certain number of miles.

3. Pre-ignition and Detonation

A head gasket can fail prematurely because of pre-ignition and detonation. Pre-ignition happens before the firing of the spark plugs. Detonation occurs after the spark plugs have fired.

These two processes produce extreme heat and excessive pressure in the engine’s cylinders. They place excessive stress on the head gasket, valves, and pistons.

4. Wrong Installation

A mechanic needs to install the head gasket correctly and precisely. If the head gasket was not installed properly, it wouldn’t be able to hold a perfect seal just after it was installed. This is a common problem for those who have to replace their blown head gaskets with a new unit.

5. Sudden Changes in Temperature

A head gasket can contract and expand depending on the engine’s temperature. It is made that way. However, abrupt temperature changes can stress the materials of the gasket. This can happen if you start the engine and immediately step on the gas.

This will produce a sudden temperature change in the engine, which can cause undue stress to the head gasket. If you habitually do this to your engine, your head gasket will eventually fail. So, allow your engine to warm up to its normal operating temperature before stepping hard on the accelerator.

How to Prevent Head Gasket Issues

There are things you can do to prevent head gasket problems. If you want to avoid this problem, you need to take the following steps:

  1. Only use one commercially available coolant/water mixture. Do not mix or add two different types of coolants.
  2. Turn off the engine as soon as it starts to overheat.
  3. Refill the coolant reservoir before it drops below pH 7.0
  4. Check and fix overheating issues. Have a professional mechanic diagnose the overheating problem if needed.

How Long Can You Drive with a Cracked Head Gasket

Head gasket repair is very expensive, considering that the engine must be opened so that repair or replacement of the gasket can be done. So, some people would like to defer the repair. But they want to know how long they can drive their car with a blown head gasket.

The answer is it depends on the severity of the head gasket issue. If there’s only a slight compression loss while carrying a heavy load, your head gasket problem is not that serious.

However, suppose you are repeatedly refilling the coolant reservoir to keep the engine from overheating. In that case, you need to have your car checked by a professional mechanic who knows how to fix a cracked head gasket.

Your head gasket problem is getting serious. Don’t let it lead to more problems, forcing you to spend more on repairs. You certainly cannot drive your car if this is your situation.

Cost of Fixing a Cracked Head Gasket

cracked head gasket repair cost

The placement of head gaskets in modern engines is deep inside the engine. That’s why fixing or replacing it is a costly proposition. On average, cracked head gasket repair cost ranges from $1,624 to $1.979.

Labor costs for this kind of work take a large part of the total. They can range from $909 to $1,147. The cost of replacement parts, head gaskets, and accessories can be between $715 and $832.

As you can see, the repair or replacement cost of head gaskets is generally way out of the range of the average car owner.

So, it is better to take the necessary steps now while your head gasket is still intact. Follow the simple steps I have provided above, and you won’t have to face this problem for the lifetime of your car.

Most car experts say that head gaskets, on average, can last 200,000 miles. They say this is equal to the lifetime of most modern cars. By following your car’s service schedules, you may be able to enjoy your head gasket for a long time.

Frequently Asked Questions

When you own a car, you are not particularly concerned about its head gasket until it causes some problems. In that regard, you may have some questions in your mind about head gaskets that you want to be answered. Perhaps the answer you are looking for is included in the list below:

How to Determine If the Head Gasket of the Engine Has a Problem?

Several signs or symptoms will tell you if your engine’s head gasket is having some issues. Here are some of the symptoms:

  • Engine overheating
  • Low coolant level or coolant leaks
  • White smoke coming out of the tailpipe or clouds of exhaust fumes
  • Rough idling of the engine or sometimes engine knock
  • Contaminated or milky discoloration of the engine oil
  • The car won’t start
  • Bubbles form in the radiator, and the reservoir overflow
  • Misfiring engine

What Can Cause the Head Gasket to Crack?

There are several causes for blown head gaskets. They include:

  • Overheating engine
  • The car is already old
  • Pre-ignition and detonation
  • Incorrect installation of head gasket
  • Abrupt temperature changes inside the engine

Can I Drive the Car If the Head Gasket Is Cracked?

Yes, you still can. But be prepared for the consequences. If the problem with the head gasket is not serious, you can still drive your car. But you may cause more serious damage to the engine if you do. Your best move is to have your vehicle checked by a professional mechanic before driving it again.

Is a Head Gasket Repair Expensive?

Unfortunately, yes, that’s true. Generally, the cost of replacing a blown head gasket ranges from $1,624 to $1.979. The labor cost takes a huge chunk of the total cost. It can range from $909 to $1,147. As for the cost of materials, it can be between $715 and $832.

The lesson is that it is better not to abuse your engine so its components can function properly for a long time.

In Closing: Signs and Symptoms of a Cracked Head Gasket

One sign that you have a blown head gasket is engine overheating just after it starts. Coolant leaks dripping from the head gasket are another.

White smoke or clouds of exhaust fumes from the exhaust is also a sign. Bubbles forming in the radiator and the reservoir overflow indicate that your head gasket is cracked.

The head gasket is a critical component of the engine of your car. It ensures that there will be no accidental mixing of different fluids inside the engine. If you see any of these signs in your engine, have it checked by a mechanic right away to prevent more severe damage to your engine.