What Causes A Blown Head Gasket?


WHAT CAUSES A BLOWN HEAD GASKET?

Do you have a blown head gasket? If you had a blown head gasket, would you know how to tell? What causes a blown head gasket anyway? Is a blown head gasket easy to fix? These are all good questions. To help answer these questions I did a little research on the topic and here is what I found.

What Causes A Blown Head Gasket?

So, what causes a blown head gasket? Acidic coolant leaks and a frequently overheating engine are two of the most common causes of a blown head gasket. The head gasket seals your engine block to the cylinder head. When your engine overheats the metals expand. When the engine block and cylinder head expand at different rates it causes gaps. These gaps can no longer be seals by the head gasket causing leaks. The inability to close these gaps is what we know as a blown head gasket.

  • What is the head of an engine? The head closes in the top of the cylinder, forming the combustion chamber. A cylinder head is usually located on the top of the engine block. It serves as a housing for components such as the intake and exhaust valves, springs and lifters and the combustion chamber.
  • What is the engine block? The engine block – also known as a cylinder block – contains all of the major components that make up the bottom end of a motor. This is where the crankshaft spins, and the pistons move up and down in the cylinder bores, fired by the fuel combusting. On some engine designs, it also holds the camshaft. (source: https://haynes.com/en-us/tips-tutorials/what-is-engine-block-what-does-it-do)

Head Gasket Failure: What Are The Symptoms Of A Blown Head Gasket?

The failure of a head gasket can have many different symptoms. As I was researching the various ways to tell if you have a blown head gasket, I came across this list of symptoms provided by Advance Auto Parts on their website. Rather than make my own list, I will simply reference theirs for you.

BLOWN HEAD GASKET SYMPTOMS:

  • Coolant leaking from below the exhaust manifold. This is the most obvious and easy diagnosis. The head gasket has failed along an outer portion, and a water passage is leaking to the outside of the engine.
  • White smoke from the exhaust pipe. This time, the water passage is leaking internally, letting coolant pass into the hot combustion chamber. Most of what you are seeing is steam and burned glycol. Other than the white smoke, the engine may operate normally until the coolant is gone.
  • Loss of coolant with no visible leaks. Sometimes the gasket barely leaks fluid into the combustion chamber, so even a watchful driver doesn’t notice burning fluid. In this case, the first symptom would be low coolant, with no sign of a leak. This is a good reminder to routinely check your fluids.
  • Overheating engine. The coolant either leaked or burned away until there isn’t enough left to cool the engine, and it overheats. Hopefully, you get a check engine light before things get too hot.
  • Bubbles in the radiator or overflow tank. This can occur when the gasket failed between the combustion chamber and a water passage. Air can get forced into the cooling system, causing bubbles. This is more serious than it sounds, as the bubbles can build into an air pocket and not allow coolant to pass.
  • White, milky oil. This is a head gasket leak between the oil passage and the water passage. The antifreeze/coolant mixture is forced into the oil, and it’s not a great mix. The cooling system takes a double hit here, as the coolant runs low while the oil’s ability to pull heat is also compromised.
  • Low power or poor running engine. The gasket has failed to the point that the combustion chamber is compromised. The engine can’t maintain proper fuel burning cycle due to lack of compression, so the result is a rough idle and dramatically decreased power.

(Data Source: https://shop.advanceautoparts.com/r/advice/car-maintenance/what-does-it-mean-to-blow-a-head-gasket)

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If you found this article purely to learn what a blown head gasket is and its common symptoms then you probably have a decent grasp from reading this far. But while I still have your attention, there is a lot more about head gaskets that you probably should know. Keep reading and I will fill you in on these other important tidbits surrounding a blown head gasket.

Can You Drive With A Blown Head Gasket?

So, can you drive with a blown head gasket? Yes, technically you can still drive a vehicle with a blown head gasket… BUT, should you drive with a blown head gasket? NO, don’t risk driving your vehicle in this condition. I suggest having it towed to a repair facility. A blown head gasket is a very bad thing for the health of your engine. It can lead to oil getting into the radiator and water into your engine. These are both bad things. You can read my article about the risks associated with water getting in your engine — [Article link: Water In My Engine Oil]. It can even lead to engine failure.

If you have a blown head gasket you need to get it fixed ASAP. I would stop driving your vehicle and get it repaired before continuing to run the vehicle. You could cause serious damage to your vehicle’s engine.

This is the perfect segway into another important question surrounding what it costs to repair or replace a head gasket.

While it is possible for some to replace the head gasket themselves, I am going to discuss what it costs to have an auto repair shop do the work for you.

How Much Does It Cost To Replace A Head Gasket?

There are many factors that go into the cost of replacing a head gasket. Make, model, engine design, and engine size (V6, V8, 4 Cylinder) can all impact the cost an auto repair shop or dealership will charge for this service.

I found the website repairpal.com. This is not an endorsement. At the time of publishing this article, I have never used their services, but according to their website, they make the following estimations:

So, how much does it cost to replace a head gasket? The average cost for a head gasket replacement is between $1,277 and $1,593. Labor costs are estimated between $1043 and $1317 while parts are priced between $234 and $276. Estimate does not include taxes and fees. (data source: https://repairpal.com/estimator/head-gasket-replacement-cost)

It’s also important to note that head gasket replacement is often done in association with other repairs. As a result, this pricing does not include the other repairs that may be required at the same time. Just thought you should know.

So what about head gasket replacement on a Jeep?

Jeep Specific Information: Replacing a Head Gasket on The Pentastar 3.6L V6 Engine

Since the primary focus of this blog is information for Jeep owners, and the Pentastar 3.6L V6 engine is one of the most widely owned engines in a Jeep, I asked my friend Justin who works for a Jeep Dealership about Jeep head gasket issues. What he shared with me is very important.

In his experience, the head gaskets rarely fail on a Jeep Pentastar 3.6L V6 engine. If it does fail, it is usually associated with another major problem such as a cam or lifter issues.

If you own a Jeep with the Pentastar 3.6L V6, and you are experiencing any of the symptoms listed in this article, get your Jeep checked out as soon as you can by a qualified mechanic or your local dealership.

Okay, so now we know what it is, what it costs to repair and replace, but how long with a replacement last? Will you have to replace it again in a few years? Also, how do you prevent the head gasket from failing?

These are all important questions to ask, and in this next section, these are the exact topics we are going to cover.

How Long Does A Head Gasket Repair Last?

So, how long does a head gasket repair last? As long as your engine is properly maintained and it runs cool and smooth, your head gasket should last as long as the life of the engine. With modern vehicles, this could be ten years or more without issue. As long and you maintain your engine and keep it working at proper temperatures, you should get a very long life out of a head gasket.

And finally, we tackle the topic of prevention.
 
As Benjamin Franklin so famously stated,
 

“An ounce of prevention is worth a pound of cure.” 

How Do You Prevent A Head Gasket From Failing?

 

Closing Thoughts

A blown head gasket is a big deal and can be costly to fix. In addition, a blown gasket is usually a sign of even bigger problems with your engine. For this reason, don’t delay routine maintenance on your vehicle’s engine.

If your vehicle breaks down how will you get to work? If you can’t get to work, how will you pay to fix your vehicle?

I know I am stating the obvious, but keeping close tabs on the health and symptoms of your engine can help you prevent catastrophic failures through a little routine and inexpensive vehicle maintenance. Have more questions about the health of your vehicle? Keep checking MyJeepandMe.com, we’re here to help. Expect to see more vehicle maintenance topics and quick fix repairs in the months to come.

Kern Campbell

I've had a passion for four-wheel-drive vehicles since I was a kid riding in the back seat of my Grandfather's Jeep Grand Wagoneer. I have owned a lot of vehicles over the years. They each have their pros and cons and I look forward to sharing my knowledge with you so you can find the vehicle that's just right for your needs.

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