In normal day-to-day operation, your Subaru shouldn't have any smoke coming from its tailpipe. Visible emissions are almost always a sign that there's a problem within the engine. While this is a negative thing, there is one positive: different problems will produce different colors of smoke, making it easier to diagnose. No matter what color the smoke is, it's important to stop driving when it's safe to do so. Then, call for a tow and bring your vehicle to Carr Subaru for service.
At Carr Subaru, we want you to have the best information concerning the care of your Subaru. Though you likely won't be able to fix what's happening with the emissions, what you see can help the technician narrow down the problem more. Check out the four things to know about visible tailpipe emissions below.
Billowing black smoke is generally a sign that the fuel-air ratio in your engine is too rich. This means that the fuel injectors are either adding too much fuel or that the intake valves aren't letting enough air in. This could be caused by a leaking fuel injector, a faulty fuel pressure regulator, or a bad air filter. If your engine is running this rich, it can cause serious problems.
Though it's easily mistaken for grey smoke, smoke that has a blue tinge can mean something different. Generally, this problem is caused by an engine that's burning too much oil. This is mostly likely caused by worn engine components, including the valve seals, piston rings, and PCV valve. In cases like these, serious engine work is typically called for since such wear of internal components means they'll need to be replaced.
However, there are other possible causes. One is too much oil in the engine. The solution to this is a little simpler: simply drain a little oil. However, you'll also want to get your car checked out, as too much oil can damage an engine. In addition, a faulty turbo seal could be the culprit if you have a Subaru with a turbocharged engine.
But if the white emissions are billowing and don't go away, you have a much bigger problem on your hands. This is usually caused by coolant leaking into one or more of the combustion chambers. Whether from a cracked cylinder head, a cracked engine block, or a blown head gasket, this will likely involve extensive work on the engine of your Subaru.
There's a chance that the emissions you see aren't smoke at all, but steam. If this is the case, count yourself lucky! Steam usually isn't anything to be worried about. It's most often caused when condensation settles in the tailpipe while your car is parked. This is a common occurrence in the Pacific Northwest winter. When you turn your car on, the tailpipe heats up and turns the condensation into steam. If the emissions are thin and go away soon after your engine warms up, you'll have nothing to worry about.