If your car exhaust is smoking when you start your car in the morning it is probably time for a car repair job. However, before you have to take your car to the mechanic to be diagnosed, you may be able to diagnose some possible causes yourself just by the color of the smoke. Your exhaust smoke will either be gray/blue, white or black. And while the exact cause cannot be narrowed down just by the color of the smoke, the possibilities can be.
If your car is smoking gray or blue smoke when you start it up in the morning and the smoke doesn't disappear after the car is warmed up there are a few possible causes. Your engine pistons could be worn and need to be replaced or your engine valve or engine valve seals may be worn and need to be replaced. None of these are do-it-yourself projects, but it should give you a starting place to start looking with your mechanic.
If you have the additional car symptom of burning more oil than normal you will likely notice when your oil is low in between oil changes. You may or may not notice that your engine is a little less powerful as a result. The cause could be your PVC system is not working right and your mechanic will need to replace the PCV valve. It is also a good idea to have your mechanic check your engine compression to determine the condition of your engine.
If your exhaust is blowing white smoke or water vapor, do not be alarmed as that is normal in cold weather, but it should not continue as the car warms up. If it continues to smoke when the car is warm it may be time to trouble shoot. It is possible your transmission fluid is entering the valve intake manifold through the vacuum modulator, which means the vacuum modulator will need to be replaced. Another possibility is the cycle head gasket is cracked or worn and will need to be replaced or resurfaced. Finally you could have a cracked engine block that needs to be replaced.
Black smoke may or may not be accompanied by other symptoms like a rough running engine or an engine that misfires. Check your carburetor choke to see if it is closed and needs replacement. It could also be a leaky fuel injector that needs to be replaced or something as easy as a dirty air filter that needs to be changed out. Finally your mechanic can check to see if your distributor cap and rotor ignition module are bad and need to be replaced.
This gives you a good guide to help you understand what car repair you may be looking at and, it will help your mechanic know where to start looking for your problem if he knows what color of smoke your are seeing.
