Your exhaust system’s components work together to ensure that the harmful gases your engine produces are being safely emitted from your vehicle. From ensuring your vehicle is getting the best fuel mileage to protecting the environment and your health, your exhaust system is important to your car’s overall operations.

The exhaust system seems to cause more concern regularly more than any other. Our experts are sometimes faced with the question, “Why is smoke coming from my exhaust?”

Much like your doctor can determine your health based on your output, our certified technicians can understand the health of your car based on the color of your exhaust smoke.

So, why is there smoke coming from your car? And what does the color of your exhaust smoke mean? Our professionals answer these questions, regularly heard at our automotive shops across the nation.

Originally published in 2015 and updated in 2020 to reflect technical and industry changes, our auto repair experts at Christian Brothers Automotive explain why smoke is coming from your exhaust, what the difference in colors mean and what you should do next to service your exhaust system.

WHAT CAUSES BLACK EXHAUST SMOKE?

If your exhaust system ever emits black smoke, it’s important to have your vehicle inspected as soon as possible. Black exhaust smoke means you’re burning fuel excessively.

Of course, this not only turns your vehicle's care mileage into something less than desirable – but it’s also an expensive problem to deal with.

There could be several reasons for this, including:

• A clogged air filter
• Clogged fuel injectors
• Damaged fuel-pressure regulator
• Clogged fuel return line

If your vehicle is burning too much gas, it’s wasting fuel and costing you money. Schedule a visit with Christian Brothers Automotive as soon as possible, so you can get your vehicle back to working order in no time.

SHOULD MY EXHAUST SMOKE BE WHITE?

In general, thin white exhaust smoke (similar to water vapor) could be nothing to worry about. Depending on the outside temperature, condensation will build up inside of your car’s exhaust system and the heat heading through the pipes will create steam.

If your exhaust system is producing a thick, white smoke – you may have a problem. Many times, this thick smoke is due to the likes of a blown head gasket, damaged cylinder, or a cracked engine block, which is causing coolant to burn.

Thick white exhaust smoke usually indicates a coolant leak, which could cause overheating and put your engine at a serious risk of damage. If this is the case, call our auto repair shop for an inspection immediately.

WHY IS MY EXHAUST SMOKE GRAY?

Similar to white smoke, gray exhaust can be difficult to diagnose directly. There are several possible reasons your car is sending gray smoke out of the exhaust system.

Some of the possible reasons include:

• An issue with the automatic transmission fluid
• A stuck PCV valve
• A faulty transmission vacuum modulator
• Excessive oil consumption
• A bad turbocharger

While these issues could be minor and inexpensive to fix, it’s important to have a professional auto professional inspect this as soon as possible to prevent further damage.

WHAT DOES BLUE EXHAUST SMOKE MEAN?

One reason your car may be experiencing blue smoke coming from the exhaust could be that your engine is burning oil. If the valve guide’s seals or piston rings are worn out, the oil will leak into the combustion chamber which in turn will burn.

When blue smoke is seen coming from the exhaust system, you must check your oil and continue to monitor your car’s oil consumption regularly. If the damage is extensive, the problem could be complex and expensive to repair. However, a minimal leak could be handled with ease by managing the oil and topping it off regularly.

If your vehicle is turbocharged and producing blue smoke, it may mean that the blower needs to be rebuilt or replaced. Either way, blue exhaust smoke always requires immediate attention. If your car is releasing blue smoke, have a professional conduct a full inspection.

Christian Brothers Automotive Exhaust System Services

If you ever see smoke coming from your car’s exhaust, it’s important to identify the color that is being emitted. When unusual fumes are coming from your exhaust, they are usually an indicator that a problem is on the rise, or is currently happening.

From burning excessive fuel to oil, an exhaust system problem can quickly drain your wallet if ignored. Ensure your car is running as it should by calling to schedule an exhaust system inspection at Christian Brothers Automotive today.