Smoke can come from the front or back of the car, and it's not good in either case. But the tailpipe will send-up colored smoke in attempt to tell you what the problem is. Here is your secret decoder ring:
Blue smoke: Oil is escaping from its intended passageways within the engine and is being burned along with fuel. Of course, you could always keep adding engine oil to the crankcase to prevent it from being all burned up (and risking serious engine damage), but the smart thing to do would be to take the car in to have any worn or damaged seals repaired [source: Torbjornsen].
White smoke: Water condensation or antifreeze has mixed with the fuel supply. Again, adding coolant or antifreeze to your car's cooling system will keep your car from overheating for as long as you remember to keep feeding the reservoir, but the wise move is to have it checked out as soon as possible.
If the smoke is coming from under your hood, that probably means you ignored white smoke coming out of the tailpipe, and now your engine is overheating. Or maybe you completely forgot to add coolant at all, and the engine overheated. Not that anyone would ever do that. That's ridiculous.
Author's Note: Top 5 Signs of Engine Trouble
I mentioned in that last tip that no one could possibly be so ignorant as to let their car run out of coolant. No one but me, that is. My first car (when I was 17) was a Chevy Chevette. I knew nothing about car maintenance, having only a vague idea about oil changes being somehow necessary. I certainly didn't know about checking fluids, or paying attention to the temperature gauge in the dashboard, or what to do when any warning lights came on. When hot, white smoke billowed from under my cheap hood, I learned very quickly about the price of coolant ignorance. It's expensive to replace an engine, even in a crappy car from the 80s.
- 2CarPros.com. "Why Is My Engine Making Noise?" (Oct. 13, 2009) http://www.2carpros.com/first_things/why_is_my_engine_making_noise.htm
- ConsumerReports.org. "What To Do if the 'Check Engine' Light Goes On." March 2009. (Oct. 12, 2009) http://www.consumerreports.org/cro/cars/new-cars/news/2005/ what-to-do-if-the-check-engine-light-goes-on/overview/index.htm
- Goodwrench.com. "How To Speak Mechanic." (Oct. 12, 2009) http://www.goodwrench.com/Tips/DiagnosingTheProblem.jsp
- Torbjornsen, Tom. "Smoke From Your Tailpipe? Know the Difference Between White Smoke and Blue Smoke." July 8, 2009. (Oct. 9, 2009) http://autos.aol.com/article/car-smoke
- Turbo Magazine. "Engine Diagnostics Part Two - Crank, Ignite, Charge." (Oct. 9, 2009) http://blogs.turbomagazine.com/index.html
- U.S. Environmental Protection Agency. "On-Board Diagnostics." (Oct. 10, 2009) http://www.epa.gov/otaq/regs/im/obd/index.htm
Can you name five signs that point to power loss for your car engine? HowStuffWorks can help you identify power loss problems for your engine.