Answers for common engine smoking problems

 

 Attention!

Most engine fluids are toxic (they can kill you) and flammable. Antifreeze tops the list and has a sweet odor so it attracts kids and animals. Please clean any antifreeze right away; a small amount can/will turn your day bad in a hurry. Be safe with your engine chemicals and all chemicals for that matter. Do not get antifreeze or other engine chemicals on your skin.

 

 

1)     Black smoke is raw gasoline burning. A rich condition can be the cause by a faulty or poorly adjusted float, a choke stuck shut, a bad oxygen sensor, a bad map sensor, a bad fuel pressure regulator, a plugged up air filter or a bad injector, too much fuel pressure or any other function that may cause excessive fuel to be ingested into the motor including a bad tune. Typically, if you only get black smoke first thing in the morning, it has to do with the choke or the fuel enrichment portion of your fuel injection system. If you get black smoke all the time, get it fixed soon or you run the risk of ruining the catalytic converter and doubling your repair bill.
Testing=check plugs for color and odor, check fuel system components


2) Blue smoke is oil burning. The tailpipe will either smoke all the time or just once, first thing in the morning. If you get blue smoke all the time, that is a sign of impeding doom. That is the first sign of the beginning of the end. Broken rings, bad pistons, damaged cylinder walls, all high dollar items.

On the other hand, if all you get is a puff or two first thing in the morning and never again throughout the day, then your problem is probably bad value guides or value guide seals, never assume that seals alone will totally fix this problem, if the engine has 100k miles plus just rebuild it. Blue smoke can also be caused by oil in the converter (After installing a new engine onto old catalytic converter(s) that were previously attached to a worn motor.)

Testing = Check plugs for color and odor. Compression check, find low cylinder add a few drops of oil in plug hole, then recheck. If compression rises bad rings are at fault. If no rise in compression, seals are probably bad. If no cylinders are bad, don’t tear the motor down until you have checked the pcv valve and other possible functions first.


3) Gray smoke can really be black or blue. You can usually tell which is it by the odor or by matching other symptoms you have to the color of the smoke.

 

4) White smoke is either;

A)    The transmission shift modulator is bad and allowing the engine to suck and burn transmission fluid.

 

B)     White smoke could also be coolant or antifreeze that is either leaking, or being forced into the combustion chambers and being burned. The exhaust will look wet and have a sweet smell to it.

 

C)    A bad head gasket (most common)

 

D)    a broken/cracked head

 

E)    a broken/cracked cylinder wall

 

Testing = Check plugs for color and odor, check oil for water intrusion (brown muddy oil), check radiator for excessive bubbles or motor oil. Warm engine and perform a pressure check on the radiator. Compression check.