Smoke coming from your vehicle's tailpipe isn't a positive sign. It indicates that something is likely wrong somewhere in your vehicle. However, there is an upside: the color of the smoke can tell you something about the nature of the problem. If you've noticed emissions billowing out of your tailpipe, schedule a service appointment soon. In the meantime, keep an eye on the smoke to get an idea of the cause. Below, we've listed what each color can tell you.
3. White or Grey Smoke
If you see white or light grey smoke coming from your Subaru vehicle's tailpipe, the first thing to do is to make sure that it's actually smoke. There is a chance it might actually be steam, and that's completely normal if your vehicle has been sitting out for a few hours. Condensation can collect in the exhaust system, especially in our rainy climate. When the engine heats up, the condensation evaporates. When it exits the tailpipe, it looks a good deal like white smoke. Duration is the easy way to tell the difference here; if it's just steam, it shouldn't last very long, and will go away by the time your engine has warmed up.
However, if the cloud is thicker or if it lasts longer, you can rule out condensation. Unfortunately, this could be a sign of a big problem: a leaking head gasket. If the gasket is leaking or blown, it can allow coolant to combine with the fuel and air mixture in the combustion chambers of your engine, unleashing a cloud of white smoke. This is something that needs to be fixed right away; failing to do so can cause extensive and expensive damage to the engine.
2. Blue Smoke
Smoke with a blue tint might signify that the engine is burning too much oil. Burning a small amount of oil can be normal in engines, but this small amount won't usually produce smoke. If you do see blue smoke, it's probably because a part like the PCV valves, piston rings, or valve seals have started to fail or wear out, causing more oil to be burned.
1. Black Smoke
A fuel and air mixture that is too rich in fuel might cause black smoke to come from the tailpipe of your Subaru. What does this mean? Well, engines use a mixture of fuel and air in the cylinder for the combustion process, and it's imperative that the mixture be just right. A rich mixture means that there's too much fuel and not enough air. There are many things that can lead to a too-rich mixture, from a clogged air filter to a leaking fuel injector to a failing fuel pressure regulator. It could even be due to a faulty mass airflow sensor. Whatever the cause, it's something that should be handled immediately. It's dangerous, smelly, and unpleasant--and it wastes money. What's more, running an engine with too rich of a fuel and air mixture can damage the engine.
Capitol Subaru of Salem
920 Auto Group Ave NE
Salem, OR 97301
- Sales: 503-587-5500
- Service: 503-587-5500
- Parts: 503-587-5500
