Colored smoke coming from your exhaust? Here's how to diagnose the problem.

Colored smoke coming from your exhaust? Here’s how to diagnose the problem.

This blog post was originally published on July 26, 2017. For most drivers, it’s not unusual to see light vapor trailing your car, especially in the early morning. Normally, this faint white smoke is nothing to be concerned about. If you see any kind of colored exhaust fumes, however, it’s time to pay attention to your engine. Your vehicle may not be flashing warning lights but colored exhaust fumes definitely indicate a problem-- and if you're not a trained mechanic, it can be difficult to pinpoint the issue. Here's our color guide to help you narrow down the potential cuplrits.

Blue Smoke

Blue smoke is typically a sign that your engine is burning oil. Worn valve guide seals or piston rings, can cause oil to leak past moving parts and into the combustion chamber where it’s burned up with fuel. Burning oil can also cause rough starts, as the leaking can ruin the car’s spark plugs. If the car is turbocharged, blue smoke can also indicate that the blower is in need of repair or replacement. Either way, this kind of smoke requires immediate attention and, often, an expensive repair.

Grey Smoke

Grey smoke is difficult to diagnose by itself, so it should be monitored it closely. Like blue smoke, it can mean that the car is burning oil or suffering from a bad turbocharger. It can also be the result of a faulty transmission vacuum modulator, which causes transmission fluid to get sucked into the engine and burned, or a clogged air filter. In any case, these problems can cause significant damage to your vehicle if not examined by a professional mechanic.

Black Smoke

Black exhaust smoke means the engine is burning too much fuel. You should have your mechanic check your air filter and other intake components, such as the fuel sensors, injectors, return lines, and the fuel pressure regulator, as soon as possible. Black smoke is usually the easiest issue to diagnose and fix, but burning extra fuel will negatively affect your fuel economy.

White Smoke

White smoke is usually nothing to be concerned about, as long as it’s thin, like vapor. This kind of smoke is the result of normal condensation buildup inside the exhaust system and will disappear quickly. But thick white smoke usually indicates that the engine is burning coolant. This could be the result of a serious issue like a blown head gasket, a damaged cylinder head, or a cracked engine block – all of which are costly repairs. Even small coolant leaks can lead to overheating, or mix with oil, and cause serious damage to the engine.

At V&F we offer:

  • Exhaust Repair & Replacement
  • Muffler Repair & Replacement
  • Tailpipe Repair & Replacement
  • Catalytic Converter Repair
  • Exhaust Manifold Repair
  • Custom Exhaust Fabrication
  • Exhaust Upgrades
Our expert mechanics can diagnose and repair problems with your exhaust, and perform regular maintenance to prevent further issues. Call us at (413)314-2280 or schedule an appointment online.  

Written by Nicole Palange