3 Reasons Why Coolant is Coming Out of Your Exhaust

If you find coolant out of your exhaust, you may be alarmed. However, while in some cases finding coolant coming out of your exhaust may indicate a serious problem, not all cases are serious.

Can Coolant Come Out Your Exhaust?

Yes, it is common for coolant to come out of your exhaust if your car has certain mechanical issues.

Coolant is circulated through the engine block in order to keep the engine from overheating. In order for it to make its way out of the exhaust tailpipe, it means it has to enter the combustion chambers.

Coolant can only enter the combustion chambers if there is a leak or crack somewhere on the engine.

How to Identify Coolant Coming Out of the Exhaust

Before starting to panic, it’s important to make sure it is coolant coming out of your exhaust and not just water.

It’s typical to see water coming out of your exhaust, particularly on cold days. This water is caused by condensation from going from a cold car to a hot running car.

To check if it is coolant or just condensation, there are a few things you can look out for:

Resovoir

If you are indeed leaking coolant out of your exhaust, your expansion bottle will start to get low. You can check this by looking under the hood and checking the coolant level according to your owner’s manual.

Color

All coolants and antifreeze have added color; this varies on coolant brands and what is required for your car. Most cars will have green or red coolant. When the liquid pools at the tailpipe, look at it and see if it is the color of your coolant; if it is, sure enough, you have a coolant leak; otherwise, it may just be condensation.

Smell

Another method of checking for a coolant leak is to smell it. Coolant has a sweet scent; if you check the smell of your coolant either from the bottle or the expansion bottle and then check your exhaust to see if it has the same smell, you may be able to decipher whether it is coolant or not. However, this may be difficult as sometimes you may just get a slightly burnt smell from exhaust.

This method is best done after your car has been sitting for a while, so the coolant may pool, and there is less of a chance of a burnt smell.

Smoke

3 Reasons Coolant is Coming Out of Your Exhaust

Typically with a coolant leak, you will also notice quite an excessive amount of white smoke; this is not to be confused with blue or black smoke, which would indicate a different problem.

Smoke from the coolant is white and is usually visible upon starting the car. Coolant smoke will also have a sweet scent as we mentioned above. 

What Does it Mean if Coolant is Coming Out of the Exhaust?

There are typically one of three issues if you have coolant coming out of your exhaust. All issues should be addressed right away to prevent any further damage to your car. 

1. Head Gasket

The most likely cause of coolant coming out of your exhaust is a blown head gasket. This is also generally the best-case scenario. Replacing a faulty head gasket is the cheapest repair of all possible coolant leaks.

The head gasket sits between the engine block and the cylinder head; its purpose is to create an air-tight seal between these two components. However, sometimes these parts break down due to faulty parts or poor maintenance. When the head gasket blows, it creates a small crack or, in some cases, multiple cracks. This allows for the engine coolant to escape the engine block and make its way into the exhaust chambers, thus traveling out your exhaust tailpipe.

It is crucial to get this problem fixed as soon as possible; failure to do so can create further problems like a cracked cylinder head which is a more expensive repair.

2. Head

3 Reasons Coolant is Coming Out of Your Exhaust

A more serious reason for coolant coming out of your exhaust is because of a cracked or warped head. The coolant or antifreeze escapes in a similar way as if it were a blown head gasket, but instead of coming through the cracks in the gasket, it actually comes through the cracks in the head.

This is a more expensive repair as it will require skimming the head or in the worst-case scenario, a new head.

3. Intake Manifold

The intake manifold is an important component of your engine that does many jobs, and one of those jobs is directing coolant to the cylinders.

Sometimes, the intake manifold may crack or blow a gasket due to high pressure and heat. This may cause coolant to come out of your exhaust in rare cases. In most cases, it is more likely for the coolant to pool on the ground underneath the engine.

Can I Drive If Coolant is Coming Out of the Exhaust?

Your car may still drive even if you have coolant coming out of the exhaust, but given the seriousness of the likely issue, it is not recommended to drive a car if it is leaking coolant out of the exhaust.

By driving a cat with a coolant leak, you risk totaling the engine by overheating. If you find you have a coolant leak, it is recommended to get your vehicle towed to your mechanic so they can assess the issue. 

If you have caught the leak early on, it will most likely be only a head gasket issue, and after a quick repair, you will be on the road again.

Final Thoughts

Coolant coming out of the exhaust may indicate serious engine issues. However, in most cases, it is usually a blown head gasket which is not a big issue; this is especially true if the problem is caught early on.

It is important to make sure it is actually coolant coming out of the exhaust and not just condensation.

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