Idles Rough When Extremly Cold out

[Doughboy21kd]

Just cant figure this one out its wierd. When ever its extremely cold out like in the teens or colder. The truck idles rough when it idles at 750, but if i bump up the high idle to above 750 that it seems fine and smooth... . It only does it when its really cold out and every once in a while at that... . I dont have any check engine lights coming on or signs anywhere else either... . The only thing that i can think is, I am not running a winter front on it and all i can boil it down too is that maybe the cold air is coming through the grill and hitting that fuel canister where the fuel filter is and maybe its trying to gel up in there causing it to idle rough... Just a thought, being the fuel filter is right there being hit with direct cold air and nothings really blocking the cold air from hitting it..... Any INPUT would be great i know if i take it to DC it wont do it... . I called them and they said don't worry about it... . THANKS IN ADVANCE

 

[mberry]

Does it do it only when the engine is cold or does it do it at all engine temps. If it does it only when cold, and only for the first 60 seconds or so then I think it's normal. Mine does it when it's cold out too and I haven't plugged in.

 

[Doughboy21kd]

Mine will do it all the time only at idle, doesn't matter if engine temp is cold or hot. And that is even after I have had it plugged in for 6 or 7 hours... . Like i said when i take off and go for a drive it runs fine all the power is there and runs excellent, but when i slow to a stop light and sit there at idle(750)rpms it idles rough, by rough i mean you can feel it through the truck, its not smooth like it should be... . For example today drove around temp was at 160 not quite at 190 where it normally runs and it idled rough... . got on the highway 50mph drove about 3 miles to next light by then the temp came up some to about 180-185 and it idled just fine and smooth... .

 

[cojhl2]

It s common for a diesel to idle rough when cold. Its just not completely firing the fuel. Also white smoke is there due to unburned fuel. Its just vaporized.



Soon as the engine has time to build some heat it will smooth out and fire correctly.

 

[Doughboy21kd]

even if my engine is at 160 thats still not warm enough to burn the fuel? If thats what your saying then thats gotta be what its doing? But i figured that 160-170 was warm enough to keep from doing that... ...

 

[WyattEarp]

im not familiar with the 3rd gen trucks or the common rail system, i do know on my 24V even at 0 degrees its will fire right up after 2 cycles of the grid heaters( i do 2 or more cycles depending on temp outside) does not idle rough but does look as if it were a gasser with smoke and vapor coming from the tailpipe. I also use alot of powerservice in my trucks not a tank goes that doesn't have a good does of additive in it, plus during the winter i make darn sure its got it in the tank, Doughboy if your plugging in and still having rough idleing after 6-7hr s of the blockheater being on then i would be checking something, that isn't right, have you checked your fuel filter, i can tell on my 24V when the filter gets dirty just by the throttle response, that might be something you need to check into, at 160 degrees in the radiator that shouldn't have anything to do with our idleing. Im not to much up on the new engines and the more complex electrical doodads but sounds like there is a idle problem. As cojhl2 said the inside of the cylinders needs to reach a certain temp before the idleing smoothes out but unless my 2000 is a rare breed even at 0 degrees it doesn't idle rough, has your truck had the high idle flash etc... . don't meant to scare you but something don't sound right if your driving 3 miles and come to a stop light and when stopped it idles rough, my bet would be to check the fuel filter first and go from there, you would be shocked at what a dirty filter can cause.

 

[Schlickenmeyer]

Not sure what you are suffering, I fired up this morning at 7 below after a 2 hour plug in and it was fairly smooth, and tonite at -12 degrees with no plug in, and it was a little slow on the cranking, but still not real rough. I run power service winter stuff and MMO at the recommended levels, but it ran the same before I started using them.



And nothing personal, but teens is not extreme cold. tonite will be -20f.

I miss the nice warm single digits. I just love Minnesota. .

 

[cojhl2]

I think he is talking about extreme cold. I missed the 160 thing. It should run smooth immed after startup at those temps.



edit,, oops now I seeit. well that is a prob. It should be smooth as silk under those conditions.



I agree with Wyattearp,, Doughboy has a different prob than cold start!!

 

[JEly]

I had mine do the same thing yesterday morning. It was 0 here and I didnt plug it in and even though it started right up it ran really really rough and there was a lot of white smoke. I did put it on hi idle for a while and it seemed to smooth out but I will be plugging it in from now on when it gets close to 0 outside.



JIM

 

[DHerzog]

If it is cold out (less than 30 degrees) mine idles rough at start up and puffs a lot of white smoke... I noticed that is smooths out and the smoke stops once the EGT gauge hit over 200 degrees (post turbo probe)... . it takes about two minutws for it to get there... .



I have been told by other diesel owners that this is pretty normal... . never have the problems when it is warmer out... .