If you smell exhaust fumes from your coolant then there’s a high degree of probability that you’ve blown a head gasket. You should shut off your engine immediately to avoid further damage. On the flip side, you may also be experiencing a sweet smell coming from your exhaust tailpipe, this is because the gasket no longer effectively seals off the two halves of the engine which keeps coolant and exhaust gases separate.

As an Amazon Associate we earn from qualifying purchases. Amazon and the Amazon logo are trademarks of Amazon.com, Inc, or its affiliates.

We might receive commissions if you click on our links and sign up/make purchases. However, please know this does not impact our reviews and comparisons. We try to keep things fair and balanced to help you make the best choice for your needs. Thanks.

Table of Contents

What Is A Head Gasket?

A head gasket is a partition that separates the cylinder heads referred to the top end, from the bottom end of the engine where the combustion happens. Its function is to seal off the area where the combustion takes place and prevent oil from the rotating assembly from mixing with the coolant that circulates through the passages in the engine block. This little part has a huge responsibility in assuring that your engine works properly.

When you “blow a head gasket” it refers to oil and coolant passing or blowing by the gasket meant to separate the two.

What Is A Head Gasket Made From?

Head gaskets can be found in three main material types, Steel, Copper, Elastomeric (rubber). Steel is the most common type of head gasket material because of its ability to withstand high pressure and comprises multiple thin sheets of steel glued together.

Copper head gaskets are far less common because they require specialized equipment to install and are made from one solid sheet of copper material. They are very capable of withstanding leaks.

Elastomeric gaskets are made from a combination of steel layers coated with a rubberized bead compound. The rubberized beads create a superior seal protecting from oil and coolant mixing.

How Long Do They Last?

Head gaskets are not generally considered a consumable item so expecting at least 100,000 miles from them is a safe minimum. It’s not uncommon to see vehicles last their entire lifetime and never have a head gasket replaced.

If you take care of your vehicle you probably won’t ever have to replace it, although if you have excessive miles is best to check when a replacement is required because materials do degrade.

Why Do Head Gaskets Fail?

Blown Head Gasket

Head gaskets only fail for a handful of reasons the primary cause being excessive heat. If you smell exhaust in your coolant or vice versa, you probably have probably experienced a head gasket failure caused by one of the reasons mentioned below.

Overheated engine

There are two reasons why an engine can overheat one is low coolant and the other is water pump failure.

A water pump’s job is to circulate coolant throughout the engine block to keep the temperature constant. When it fails, the coolant doesn’t circulate and is unable to draw heat from the engine.

As excess heat builds the metals in the engine expand too much, making the head gasket ineffective resulting in oil and coolant mixing.

Low coolant works similarly to a failed water pump in overheating an engine. The lack of volume from the coolant can’t remove enough heat from the engine, causing the same result. That’s exactly why you shouldn’t drive with a leaking radiator.

Rough Cold Starts

The metals in your engine and head gasket expand at different rates. If you start a car and rev it hard without properly letting it get up to temperature, it can cause excessive heat build-up warping metals, and blowing your head gasket.

Time and Age

Things break down with age and time. Although head gaskets are made to be robust and withstand time, all things break down eventually. Although high mileage doesn’t necessarily mean age, it does mean many heat cycles for your engine. So if your car is getting up there with age or mileage its good to have your head gasket checked out.

Can You Drive With A Blown Head Gasket?

There are many things you could do but generally, it comes down to whether your should. In the case of blown head gaskets, you definitely should not do it. Driving with a blown head gasket will destroy your engine. With coolant and oil mixing getting into the combustion chambers, it can cause cylinders to seize and will require a complete overhaul.

If you suspect your car has blown head gasket, do not drive until you know for certain. A head gasket replacement is a big job but it can be done. A tow to a mechanic shop may sound like a lot of money right now but I assure you it’s much cheaper than buying a new engine.

How To Fix A Blown Head Gasket

There are two ways to fix a head gasket. The cheap and temporary way, or the right way, which is permanent and more expensive. Word of advice, unless you really don’t care about your vehicle or on really hard times, don’t go for the cheap option. As with a lot of things in life, sometimes the cheap way actually ends up costing you more in the long run.


There are a number of head gasket fix products out there but products like bar’s leak head gasket fix seem to have good reviews and work decently well. It works by filling up the passages in your head gasket that has separated between the top and bottom end.

You’ll see that a lot of products in the head gasket fix department will advertise as permanent but I still qualify them as temporary because most products will give way again unless you add more product somewhere down the line.

How To

Each head gasket leak fix product will have its own set of instructions on how to use it properly so make sure you read them before using them. They all generally work by flowing through your coolant system and finding their way to the problem area.


The cost for a head gasket fix in a bottle is usually anywhere from $10 on the low end up to $50 on the high end. It may be worth a shot if your vehicle’s value isn’t worth the repair cost.


Replacing the head gasket is the right way to do it to ensure no further problems. This involves taking the engine apart to get to the bad gaskets. It’s labor intensive but if you are handy it’s possible to do them yourself.

How To

The process of replacing a head gasket involves the draining of your coolant system followed by the teardown of the engine and removing the cylinder heads in order to have access to the gaskets. Depending on how complicated your engine is, many things might have to be removed before you have access, including intakes, electronics, valves piping, and more.

Once you have access the gaskets slip into place and everything gets put back in reverse order. Coolant is replaced and the vehicle is permanently fixed.


This method is by far the most expensive, especially if you have to pay a shop to do it. The time it takes to take the engine apart could be very long and with labor rates, it can cost thousands. A head gasket job can be anywhere from $800 on the low end to $3000+ depending on the complexity and specificity of the vehicle.

In Sum

You really have to evaluate what your vehicle is worth to you. If your vehicle is old and isn’t worth very much anymore a repair like this can effectively total your car. However, if your car has some life and still has some market value it might be worth doing, especially if you can do the work yourself.

Big repairs are a big reason why maintenance is king when comes to keeping a vehicle on the road, what do you think?

As an Amazon Associate we earn from qualifying purchases. Amazon and the Amazon logo are trademarks of Amazon.com, Inc, or its affiliates.

We might receive commissions if you click on our links and sign up/make purchases. However, please know this does not impact our reviews and comparisons. We try to keep things fair and balanced to help you make the best choice for your needs. Thanks.

(Visited 3,007 times, 1 visits today)