Smoke Colours?

[silvtr1000]

What do the different colours of exhaust smoke mean? And what do they mean in different circumstances?

EG:

Start-Up

Black Smoke

White Smoke

Blue Smoke


Changing Gear

Black Smoke

White Smoke

Blue Smoke


Under Power (on acceleration)

Black Smoke

White Smoke

Blue Smoke


All The Time

Black Smoke

White Smoke

Blue Smoke


Some of theses scenarios may not even be possible for all I know, and there may be other colours I'm not aware of, but I'd really apreciate it if someone out there knew the answers.

It's been my understanding that any smoke was usually a result of OIL being burnt, or at least related to OIL, not fuel.

I changed my fuel filter yesterday, and where I have usually had a puff of dark smoke (more grey than black) on start-up, followed by a fair amount of white smoke (which stops after a few minutes of driving), I now have little or no smoke of any colour on any of the start-ps since, nor on acceleration or on gear changes.


Thanks All & Happy Monday!

Mark

[Slugsie]

If I recall correctly, blue smoke is engine oil being burned and generally a bad thing. White is water, and generally a bad thing too (unless you've put some form of cleaner in in which case you can get copious amounts of white smoke for a little while, in which case it's probably an OK thing). Black smoke is unburned diesel, and generally not a problem unless there is a lot of it all the time.

But I may be wrong....

[Guest]

If I recall correctly, blue smoke is engine oil being burned and generally a bad thing. White is water, and generally a bad thing too (unless you've put some form of cleaner in in which case you can get copious amounts of white smoke for a little while, in which case it's probably an OK thing). Black smoke is unburned diesel, and generally not a problem unless there is a lot of it all the time.

But I may be wrong....

Yep that's basically it. Black smoke on startup is generally a given, Blue smoke at any time is generally not a good thing, however if the engine sounds OK, it doesn't knock loudly, doesn't use too much oil and oil pressure is good, generally isn't that bad a problem, rings starting to wear a bit, valve stems worn a bit.

White smoke is not a very good thing at all, unless it is for a short time on startup when it COULD be condensation burning off - generally only if the vehicle only gets used on short runs and never gets a blast.

Smoke is only ever an indicator, oil pressure, water temp, driveability, and noise are often better indicators of serious problems.

Cheers

[TonyN]

Looks like the Red Arrows team tactics!

[silvtr1000]

Thanks Guys.

[jeff.fn02jwa]