BAC Forum

General Boards => Technical Support => Topic started by: Steve Adams on July 28, 2011, 04:43:20 PM

Title: Black smoke, white smoke.
Post by: Steve Adams on July 28, 2011, 04:43:20 PM

All,

Since we've owned our coach there has usually been a puff of black smoke when starting, especially if the engine has not been run in 2-3 days. It is just one black puff then nothing.

Yesterday I noticed white smoke abour a minute into our trip. We had idled about 3 minutes before hitting the road, temps were about 60 degrees. When I mentioned it to my wife she said she's noticed it a number of times and all of those occasions were shortly after start-up. She said it always stops within a few minutes of getting on the road.

What should my concern level be? What is causing this?

Thanks, Steve

Title: Re: Black smoke, white smoke.
Post by: Richard And Babs Ames on July 28, 2011, 05:36:34 PM

White Smoke is usually a sign of moisture in the combustion. If it was a lot of white smoke and lasted a while, I would be concerned. If you are not using coolant, and gauges have good readings, you are probably OK.

Title: Re: Black smoke, white smoke.
Post by: Wayne Baumann on July 28, 2011, 06:09:29 PM

HI HAD THE SAME THING HAPPEN TO MY C9 ENGINE, AND IT KEPT GET WORSE THE LONGER I DROVE IT.  IT FINALY HAD NO MORE POWER, AND HAD TO GET TOWED TO DENVER CAT DEALER. THEY FOUND THAT #5 INJECTOR WAS STUCK WIDE OPEN.  THIS IS THE SECOND TIME #5 HAD TO BE REPLACED.  HOPE THAT THIS INFORMATION HELPS  YOU.

WAYNE BAUMANN

Title: Re: Black smoke, white smoke.
Post by: Gerald Farris on July 28, 2011, 07:33:21 PM

If your engine is idling smooth and you are not loosing coolant, you have nothing to be concerned about.

Gerald

Title: Re: Black smoke, white smoke.
Post by: Joel Ashley on July 29, 2011, 12:35:21 AM

I have to agree there is nothing unusual in what you are seeing, Steve.  On startup, cold incompletely burned fuel and residual lubricant are exhausted briefly, followed by any settled water vapor condensate in the air intake, turned to steam in the cylinders.  The air cleaner and intake components in the engine compartment were warm when you last turned the engine off;  subsequent cool-down condensed any warm vapor in the system, and the moisture creates the white "smoke" on next startup.  If the white exhaust didn't stop after a bit, then I'd worry about a coolant leak.

-Joel  

Title: Re: Black smoke, white smoke.
Post by: Steve Adams on July 29, 2011, 01:05:30 AM

I knew I could count on you guys to set me straight!

Thanks, Steve