Engine/Transmission (1998.5 - 2002) Blue smoke on cold start

[Silver Bullet Ram]

Did this yesterday, never seen it before. Reved the engine a couple of time belched a little more then turned black and cleared up. Don't know if this is related or not, but the engine has been a little noiser here lately. Lift pump is working.



Gary

 

[KampinKid]

Hey Bullet, Same here. . been doin' it since it was new. I remember living in the midwest and seein' the big rigs startup on cold winter mornings and smokin' white till they warmed up then all was fine. I've convinced myself it's normal and hope i'm thinkin' right if not someone will chime in. Maybe some of the more knowledgeables here can explain the technical aspects of the phenomena... . ie; cold exhaust, cylinder temps, fuel viscosity, ect. So till I'm told otherwise I'm not takin' to much concern in the white stuff on cold starts as long as it clears up within a few minutes. Kid

 

[DTroy]

I wouldn't worry about the white smoke on start-up. It's caused by the cold cylinder walls soaking up some of the heat from the compression stroke. (causing poor combustion) As the block warms, the smoke clears.

Blue smoke on start-up that also occurs during long periods of idling and especially after blipping the throttle after a long idle, is from the turbo.

 

[R-N-R]

White smoke = fuel / blue smoke = oil ?

 

[DTroy]

Yes, white is usually fuel and blue would be smoke. Somehow I left out the word oil.



If someone had a bad head gasket, etc. . they could also have white smoke.

But you can usually smell the difference. And the coolant smoke usually wouldn't clear up like the fuel smoke.

 

[Silver Bullet Ram]

Only does it when it is cold out.

 

[gonehuntingagain]

When it is cold out, blue smoke is normal until the engine gets enough heat to fully burn the fuel. White smoke that happens a few minutes after startup is the exhaust system warming up and producing steam from the moisture that builds up after shutdown.