Ask a Folger Subaru Technician: What Does My Car Exhaust Color Mean?

Finding trouble with your car early can help you avoid an unwelcome repair bill. The color of your car's exhaust can be a useful means of health checking what is happening elsewhere on the vehicle.
 
As your engine burns fuel and creates exhaust, a number of different processes are taking place. If you spot different colors in your exhaust emissions, you could be spotting the early signs of problems to come.
 
Blue or gray smoke can sometimes be seen coming from the exhaust, particularly when the car is first started. Sometimes the smoke will disappear and become difficult to spot once the engine has been running for a while.

Blue or gray smoke can indicate a number of different problems:

• There may be a problem with the piston rings. You will need to ask a technician to inspect and possibly replace the parts.
• The engine's valve seals may be worn or faulty. Again, you will need to ask a professional to replace them.
• The valve guides may be worn or damaged. This is definitely not a job that you want to do yourself.

White smoke often appears from your exhaust and may well be perfectly normal. Your car will very often emit white smoke when first started, particularly during very cold weather. The problem arises when the smoke does not go away. If your exhaust continues to emit white smoke after it has been running for some time, then there could be a problem.

• It is possible that the engine block is cracked. Your technician will need to replace it.
• One of more of the cylinder head gaskets may be faulty and will need to be replaced.
• It is possible that one (or more) of the cylinder heads has warped or cracked. You will need to ask your service department to replace the parts for you.

Black smoke is another common symptom of a car with mechanical problems. The smoke may be very thick and choking when you first start the engine and may or may not disappear when the car has been started for some time. It is also quite common for the engine to sputter or misfire at the same time.

• There could just be a problem with the air filter. You would normally be able to replace this yourself.
• It is possible that your fuel injectors are leaking. You will have to get a professional to inspect and replace.
• There could be a problem with the ignition. You should check the distributor cap and rotor or ask our technician to inspect for you.

Observing the early signs of a problem with your car could prevent huge repair bills later. It's worth learning the problems that colored exhaust emissions could indicate to help you get to the root of the issue as quickly as possible.

For more information, click here for the Folger Subaru Service Department or call (866) 306-3293