To some degree, you shouldn’t be surprised if your car is smoking. It’s part of being a car. So, the answer to the question, “Is it okay for your car to smoke?” is ‘yes,’ but with conditions. In other words, a certain amount of smoke, and a certain type of smoke is normal. But not all smoke produced from your car is okay.

What kinds of smoke can you expect from your car without alarm and what kinds of smoke are bothersome? Here are some considerations:

Exhaust smoke from the tailpipe: A certain amount of smoke from the tailpipe is normal. When you start the car, you may see a cloud of smoke coming out of the tailpipe, but it should quickly dissipate down to a nominal level.

On the other hand, if big clouds of white smoke pour out of your tailpipe for an extended period, this is cause for alarm. You should stop the car, and shut off the engine, as soon as possible. You may have a bad head gasket or something else allowing coolant into the cylinders. The car can overheat and be damaged in a short period of time.

Blue smoke from the tailpipe can indicate that oil is getting into the cylinder and burning. It’s a definite indication of a possible problem with the engine.

Black smoke suggests that the fuel mixture is too rich; there is too much gasoline pumped into the engine. You may have problems with the fuel system, sensors or even a clogged air filter that is limiting the amount of air mixed with the gasoline.

Gray smoke could indicate a problem with a turbocharger if your vehicle is so equipped. Or it could indicate trouble with transmission fluid or the transmission vacuum modulator.

Smoke from under the hood: A little smoke under the hood can indicate a valve cover gasket is bad. Oil is leaking out and onto the exhaust where it burns off making little puffs of smoke. You should have this fixed but not with the sense of urgency mentioned above. You may also have smoke produced by a car that is overheating and may have leaks in the cooling system. This is a more critical matter and should be addressed promptly since, once again, the engine can overheat and be damaged.

Smoke coming out from under the car could indicate that transmission fluid is dripping on the exhaust and burning off or that you have a hole in the exhaust system.

You may also have smoke coming out of the air vents inside the car. This may be easily explained as the reaction of cold dry air coming into contact with warm, moist air. But, it can also indicate a leak in the heater core. If it continues, or if it has kind of a sweet odor, you should have it checked out by a qualified auto repair technician.

Finally, if your car is on fire, it will create dark, billowing clouds of smoke. Get out and get away from the car as quickly as possible.