Why is White Smoke Coming from My Exhaust

From strange noises, low power, and lights on the dash, there are many ways your car can alert you to a problem. Thick, white smoke billowing out of the tailpipe is a sign that something is very wrong and shouldn’t be ignored. Read on to learn more about the causes of white exhaust smoke, and the repairs associated with stopping it.

White Smoke vs Condensation

Most vehicles will emit a small amount of white “smoke” when the engine is first started, especially on cold mornings. This “smoke” is simply condensation (water) in the exhaust turning to steam when the engine is running. The steam will dissipate within a few minutes once the condensation has burned off.

Smoke, on the other hand, will be thick and billowing. Depending on the severity, it may be difficult to see if you are standing behind the car. It’s pretty easy to tell the difference between normal condensation and actual exhaust smoke.

What Causes White Exhaust Smoke?

Billowing white smoke coming from the tailpipe indicates that coolant is entering the combustion chamber and burning. Normally, coolant circulates through the engine block separate from the cylinders and oiling passages. White smoke means there is a leak someplace in the system and unfortunately, it’s going to be a big repair.

Head Gasket Failure

The head gasket seals the cylinder head(s) to the engine block, preventing oil and coolant from mixing or entering the combustion chamber. A blown head gasket can be caused by overheating, incorrect installation, high mileage, or abrupt temperature changes. Fixing a blown head gasket is an in-depth repair that involves removing the cylinder head to access it. This is not a job that most people can do at home.

a used head gasket

Cracked Engine Block or Cylinder Head 

While a blown head gasket is bad, a lot of the time the engine is fine and can be saved by replacing it. The other primary cause of white exhaust smoke is generally the death throe of an engine. When a crack forms in the engine block or cylinder head, coolant can enter the combustion chamber.

A cracked block is technically repairable, but in the vast majority of cases replacing the entire block (or engine) is a better option.

A cracked cylinder head will need to be replaced as well. In this situation, it’s worth comparing the price of replacing the head alone or the entire engine.

freshly machine engine block

What to Look for Besides White Smoke

You should not drive your car if you have white smoke coming out of the tailpipe. Whether it’s caused by a crack in the head or block or a blown head gasket, the engine is at a greater risk of overheating, which will cause even more damage. Some things to check (once the engine is cool!) include the coolant level and the oil.

Contaminated oil will look thick and creamy like a brown milkshake. Take a look at the dipstick or under the oil cap. If the contamination is severe, it will be pretty obvious just by looking at the oil.

Checking the coolant level will tell you whether or not coolant is being consumed by a leak. A normally functioning engine will not lose coolant.

Get Professional Help

Diagnosing any issue is difficult. Having a technician take a look is the best way to know for sure. Not only will you get an accurate diagnosis, but you’ll also get an estimate of the cost of repairs and the best plan of action for getting you back on the road.

Auto Repair at Scott’s U-Save

Scott’s U-Save Tires and Auto Repair is your destination for all things tires and automotive. Our teams of experienced technicians at our stores in New Lenox IL, Steger IL, and Schererville IN can quickly get to the bottom of the issue that causing your vehicle to emit white smoke. Give us a call or schedule an appointment online today!


Schedule An Appointment

Whether you're shopping for tires, looking to lift your truck, or need auto repair, Scott's U-Save is here to serve you! Schedule an appointment online or call today!

Get In Touch