Black smoke from exhaust
im dave; hope i can help
First you need to determine if it is actually black smoke or if it is blue smoke. There are three colors of smoke that can come from the tailpipe. It is not white smoke obviously because that is easily differentiated from blue or black and generally indicates water or antifreeze leaking past the head gasket and into the compression area of the motor. White smoke is the steam of the water/antifreeze being emitted
Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles. The car has many seals, gaskets, and o-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plugs, it will cause a misfire(engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.
Black smoke is caused by excess fuel that has entered the cylinder area and cannot be completely burned. Another term for excess fuel is "running rich". Poor fuel mileage is also a common complaint when black smoke comes out of the tailpipe. Black smoke out the tailpipe is the least cause for alarm. Excess fuel will usually effect engine performance, reduce fuel economy, and produce a heavy fuel odour in the engine compartment. Some of the causes of excess fuel are a carburetor that is out of adjustment which is not likely unless you have installed an aftermarket carburated system on your non-carburated car, a faulty fuel pump, a leaky fuel injector, or a faulty engine computer or emissions sensor. If black smoke is present, check the engine oil to make sure excess fuel has not contaminated it. Do not start the engine if a heavy, raw fuel smell can be detected in the engine oil. Check the above mentioned systems and after detecting the trouble replace the faulty parts and then the engine oil and filter.
Jul 20, 2008 |
1996 Pontiac Firebird