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Discussion Starter · #1 ·
When cold start no matter the temp always blows white smoke and acts like its missing. Thought it was bad injectors and put a 6 pack of 30% over because why not and still has the same problem. Not loosing coolant, no fuel in the oil but after it warms up and throughout the day it wont do it. Only when it sits over night. Can't figure this one out I need HELP.
 

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Is the truck deleted?

Deleted trucks will do this but just a tiny bit of white smoke then it will clear up, mine will do it a bit more in the winter but it's usually -30 to -40c here
 
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2015 Ram 2500, Longhorn Laramie LTD, 6.7L CTD
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Is the truck deleted?

Deleted trucks will do this but just a tiny bit of white smoke then it will clear up, mine will do it a bit more in the winter but it's usually -30 to -40c here
Yep, if you've got no emissions this is a normal occurrence until cylinder/coolant temps come up.

Op this your first winter with the truck? How cold is it when this happens?

A bad battery/batteries will cause stumbling as well.
 

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It's deleted but it was doing it before hand, it doesn't stumble. The weird part is I can put it in gear and it will go away when a load is on it.
Sorry when you said earlier it acts like its missing (I said stumbling), is it actually missing or you just think it is because of the white smoke?

What range of outdoor temps does this happen? How many miles on your injectors?

If you're putting load on it it will increase fuel pressure so this could also indicate that your fuel pressure is lower than required and causing issues. If that's true then you could have a failing FCV FCA or rail PRV.

It's not uncommon that the injectors can leak down fuel into the combustion cylinder overnight and cause white smoke on startup and then not after that. Typically though your FCV should be opening full on shutdown to bleed off rail pressure.
 

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Discussion Starter · #6 ·
It happens at all Temps, 8000 miles on new injectors. I thought it was because of the white smoke. I will replace both FCV and the PRV and see if that fixes the issue. Thank you
 

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It happens at all Temps, 8000 miles on new injectors. I thought it was because of the white smoke. I will replace both FCV and the PRV and see if that fixes the issue. Thank you
You can test this stuff before replacing it... Don't just go changing parts first. Are those OEM injectors, reman, or aftermarket? If anything other than new Bosche OEM I'd be highly suspect of one or more of those 'new' injectors.

For example, a simple way to test the FCV you can unplug it and start up the truck in the morning and see if it still cold starts, this will direct full pressure to the fuel rail. Don't run like this for long, just see if the smoke is gone. You can also trend your fuel pressure if you have something like a bluetooth OBDII reader.

Ok what does PRV and FCV stand for?
Pressure relief valve and Fuel Control ValveActuator. The PRV is installed on the rail and it's function is to protect the injectors/fuel rail from overpressure.
The FCA is on the CP3 and it controls fuel rail pressure by diverting fuel to the tank.
 

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Pressure relief valve and Fuel Control Valve. The PRV is installed on the rail and it's function is to protect the injectors/fuel rail from overpressure.
The FCV is on the CP3 and it controls fuel rail pressure by diverting fuel to the tank.
Not that it matters much, but FCV should actually be FCA, Fuel Control Actuator. Only matters if you are trying to order a new part.
 
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Not that it matters much, but FCV should actually be FCA, Fuel Control Actuator. Only matters if you are trying to order a new part.
I think you're right. MOPAR calls it a FCA not FCV. FCV (flow control valve)is what my work calls these types of things.
 

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It depends on your calling “white” smoke, but it could also be turbo seals. This sounds a lot like what mine was doing until I finally saw oil drip out the tailpipe. I had too small of a turbo drain for this particular turbo.
 

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It's still the stock turbo. It doesn't do it when it's above 40
Didn't you say earlier it does it at all temps? It's somewhat normal for these guys to smoke a bit.Do you still have grid heaters? What's the humidity where you live?
 

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Mine does this when sitting overnight. It is worse when cold, but clears up quickly.
 

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It's worse when it's cold. Slightly does it when it's warm. Midwest humidity, no grid heater
OK, this is exactly what you would expect to happen with your current setup. You don't have a problem unless you count the fact it was self-inducted by removing the emissions components that would otherwise prevent such a thing....

The cylinder walls are cold and so is the intake air. Until the cylinder walls heat up and raise combustion temps you will get unstable combustion. Grid heaters warm the intake air and help eliminate this problem. EGR recycles hot combustion gas back into the intake basically eliminates it. When you remove these two, well, you get unburnt diesel exiting the exhaust.

Plug the truck in to mitigate this when it's colder than 59F out.
 

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It's worse when it's cold. Slightly does it when it's warm. Midwest humidity, no grid heater
Should've mentioned you removed the grid heater from the get go, no wonder it's worse when it's cold.

The preheat grid heater cycle is determined by the intake air temperature. It will start at 59f (15c) or colder

Post-heat cycle initiates after engine start to assist cold weather running and reduce exhaust smoke. Post-heat will run up to 3 minutes.

I have a grid heater still without the emissions and mine will have a brief smoke for like 10 seconds upon fire up while sitting all night
 

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Discussion Starter · #19 ·
It did it before I removed the emissions and grid heater. That's why I did injectors because my other trucks I had did the same thing and the injectors fixed the issue. But this is my first 6.7. With emissions.
 

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It did it before I removed the emissions and grid heater. That's why I did injectors because my other trucks I had did the same thing and the injectors fixed the issue. But this is my first 6.7. With emissions.
Could be your tune, hard to say. IMO if it's smoking a bit around/below freezing without a grid heater I'd say you've got what you paid for. Did you replace all the way up to the turbo or just up to the factory flex/down pipe. If you did replace back to the turbo it's likely you no longer have the HC catalyst as well.

What was your other truck? The 3rd gen trucks had in-cylinder EGR.
 
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