Black smoke

[duncan_sheek]

mge peeps, my car is corolla 1990 or ae92. last saturday nagpa-tune up ako pero when i rev the engine medyo maitim parin ang usok coming out of the mufler. sabi ng mekaniko sa valve seal daw. gusto ko lang itanong sa inyo what do you think. thanks in advance.

[jeegoogs]

nababawasan b level ng engine oil mo? basa ba exhaust end pipe mo?

[1D4LV]

pwede nga valve seal. baka nga may tagas ang langis mo to combustion. black smoke means burned oil, i think.

[nicolodeon]

Something I learned from a fellow I met through the Interet:

White smoke:The white smoke, which is steam, is caused by water and/or coolant entering the cylinder, and the engine trying to burn it with the fuel. Any amount of coolant that enters this area will produce a white steam that will be present at the tailpipe area.

If white smoke is present, check to see if the proper amount of coolant is inside the radiator and the coolant container. Trey to check to see if the coolant has contaminated the engine oil. You would know if the oil is contaminated if it is chocolate in color. Do not start the engine if the oil is contaminated with collant: serious internal engine damages could result.

How did this happen? The engine probably overheated at one time and a head gasket failed due to excessive heat, thus allowing the coolant to enter the cylinder.

Blue smoke: The blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel/air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely to occur in in older or higher mileage vehicles.

If too much oil leaks into the cylinder and fouls the spark plug, 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: The black smoke is caused by excess fuel that has entered the cylinder area and cannot be burned completely. Black smoke coming out of your tailpipe usually means poor fuel mileage. However, black smoke is one of the least causes for alarm, although excess fuel will usually effect engine performance, reduce fuel economy, and produce a fuel odor.

Some of the causes : carburetor that is out of adjustment, a faulty fuel pump, a leaky fuel injector, or a faulty engine computer or computer sensor. If black smoke is present, check the engine oil as in the white smoke example 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.

[jeegoogs]

agree....

[duncan_sheek]

hindi naman nababawasan level ng engine oil ko pero medyo basa ang exhaust when i start & rev the engine... but when i used the car, medyo nawawala na ang sobrang black smoke...

[jeegoogs]

hmmm.. normal lang kasi sa umaga na may konting H20 ung exhaust dahil sa moisture(dew point ng hangin) pag top condtion un gasoline engine mo.try mo lang tangalin un air filter mo for a while baka barado na then observe if still has black smoke.kung mawala un black smoke,renew the air filter.kung maitim parin after the test,pa adjust mo nalang ang air / fuel mixture ng carb mo.

pero mas ok kung pa check mo nalang sa casa.......:-)

[nicolodeon]

Kung may konting moisture pag pina-start mo for the first time during the day, normal yun. Sabi nga ni JG, it means na in very good condition yung gas engine mo. Pero, yung yung water eh medyo slow drip na parang faucet na at may black smoke pa, parang something is not right. As JG said, tey mo i-adjust yung air/fuel mixture.

[vinj]

If it comes out especially during high revs, chances are you're running too rich. Carb adjustment katapat nyan.

[duncan_sheek]

oh ok, so hindi sa valve seal ang problem? nagtanong kasi ako kung magkano aabutin pag pinalitan valve seal ng 16 valve engine, around 4k daw... try ko ang advice nyo about adjusting air/fuel mixture ng carb. thanks guys.