i know i have asked this another thread but really didnt find an answer.

scenerio 1- cold morning 0-20 degrees. cycle the key twice then i start up. motor goes to instant 1000 rpm. truck will do this for up to 15 min or if you hit the brake it goes to straight normal idle but it wont go to normal idle when you hit the brake until after at least a min.


it seems i have only 03 that that high idles like this. so my question is this good for the motor idle that high lets say when is minus 30. i hear a lot of mixed things on this. so goooood or baaaad.

 

Better for it to high idle when cold than to idle at normal rpm .keeps the motor warm and cylinders from being washed down and to cold to burn correctly.Atleast thats what i have heard and read before.

 

It's what Cummins has designed the motor to do.

If you have a cold start and idle, the cylinder temps can fall, causing a fuel wash down in the cylinders.

If you think about it, generators fire up and go to max load right off the bat... they were designed to do this.

1000 rpm's-not that much higher than idle if you think about it.

 

thanks for the answers, thats what i been looking for......

 

That being said, you want to make sure your service is up and your oil is good, fuel is good...

 

Mine does it as well. Completely normal.

 

Same here mine does it also

 

Yes they all do this in the cold. Also after driving if you stop and let idle after a few minutes when engine starts to cool down it will idle up again on it's own. You could also have the high idle enabled with the cruise control if you have auto tranny.

 

Mine does it also. If temps go below 40 F., I plug in on a timer of course. After I un-plug and start, it idles normal for 3 min. and jumps to 1000 rpm

Chip

 

mine starts-up the same way....except when it has been plugged-in for awhile.....several hours.

 

cycleing the key twick is a waste of time... 0-20 is not that cold for these things.

i have never had to do this, and i have started mine on one cycle when the temp was -17 without the wind chill...

and mine high idles like that right at startup if i haven't plugged it in...