Smoke - what does it mean?

[_luke]

This is a true new-to-diesels question...



What can you tell about your truck from the amount & color of the smoke it puts out?



My truck seems to smoke more than others I've seen/driven. It's not bad, but since it's all stock, I didn't think it would smoke at all.



Does more smoke mean the engine is worn? Out of tune? Fuel problems?







thanks,

_luke

 

[PHX ATC]

The turbo isn't making as much boost as it should to properly supply the air for the amount of fuel your dumping in the cylinders.



A low boost situation and high fuel would result in smoke, which is alot of unburned fuel dumping out the exhaust. Black smoke, that is, not white. White smoke is bad unless there's a teeny bit on startup.



Say your cruising at 55 mph (like you'd ever do that) in 6th gear, you spot a Powerpuff trying to overtake you, you punch the throttle and smoke pours out the exhaust... that would be a situation where there's low boost and lots of fuel. Eventually the turbo will catch up (turbo lag) and send the air into the cylinders to catch up to the fuel you're dumping in there.



I'm sure somebody will have a technical explanation, but that's down and dirty layman stuff.



Toby

 

[fkovalski]

I believe that altitude would also have an effect (read as: less air) Even though Boulder is at a lower altitude relative to where I am, it is much higher that most locations. Less air = moore smoke. Here at 9,000+ feet, mine smokes more than when head down to your elevations.

 

[lmills]

Did you buy the truck as a first owner? Or was it previously owned?

 

[_luke]

I am the second owner. The truck used to be a ranch truck in TX. I'm hoping it wasn't abused too much.



I'm sure the elevation has some to do with it. I'm actually moving to higher elevation next year too - 9600 ft.



Would higher boost pressure help?

 

[CFAR]

How do you know its stock??????

 

[_luke]

good point. I don't really know. Any ways to find out?

 

[lmills]

If the injectors have been changed, you might not be able to find out. Most of the aftermarket companies just enhance the stock bosch injectors. So if you pull an injector it will probably have the same part number as a stocker.



Do you have boost and egt gauges? If so how much boost are you seeing?

 

[dpuckett]

Not sure on the 24v engines, but I've had a few 12v engines that had absolutley HORRIBLE injector atomization at 120K mi- 500 psi low on pop presure, no spray- more like a Windex bottle set to stream. That can cause smoke. As can a bad air filter, plugged fuel filter. White smoke would be a fuel dellivery problem- either retarded timing, or not enough flow amount (pump wearing down). Injectors not up to par will make white smoke as well.

With the 10cm (or is it 12? I get confused) exhaust housing, you should get almost instant throttle response, with VERY little smoke. Ex's dad came to visit us in CO from MN in his 01 HO/ 6spd, and his didnt smoke once we got the air filter changed.



A little wisp of smoke when you floor it off the line to outrun that college kid in his $20K ricer is acceptable, though. Big clouds of black smoke are not. How was your e-test opacity?



Daniel

 

[Cummins Pilot]

Mine puffs some black when I stomp on it. I don't worry about it. But I have seen some trucks pour more black smoke out than a 40 year old Mack truck. Excessive can indicate problems. A puff isn't a big concern most of the time. It also helps get rid of the little ricers when they are near the tail pipe.