I have a block heater for my truck, but when I start up, she idles really rough. Once she is warmed up, there aren't any problems.

Anyone have an idea of what is going on?

Thanks-
Eric

 

Any smoke? if white, you might try some injector cleaner to start. Some folks here feel rough idle and some white smoke during cold morning starts are the norm but not sure I agree. My experience is only with 3 CTD over the past 10 years and the only times I got rough idle on cold mornings WITH some White smoke is when I had dirty injectors.

The idea is the dirty injector gets sticky and a little bit of fuel leaks into the cylinder over night.

 

it may just be because it is cold, my truck starts up rough when it is about 40 outside, but you say it does go away, so there should be any problem

 

Are you reving the engine up to about 1k after starting per the instructions on the visor? What type of oil are you using? 100% Synth oil doesn't see it as often because it flows better at lower temps. When was the last time you changed the oil and the fuel filter?

 

3,000 miles ago on both. I use rotella oil. My truck is a manual and doesn't have that information on the visor.

 

my truck had spuratic rough idle, 2 days ago i installed a rokktech, it hasnt done it yet. take a look at the crank sensor head, mine had a pretty thick layer of crude on it..idk if i had just cleaned the stock sensor it might have helped, but im glad i got the rokktech in cauz it runs and sound a whole lot better then before.

 

Mine idled very rough on cold starts. I finally figured out that I had picked up some poor quality diesel. A dose of Howe's Meaner Cleaner and some Power Service along with a new fuel filter cured it in 1/4 of a tank.

 

What is a rokktech? A programmer?

If it was my crank position sensor, my pda would show a tuner fault. I put some Lucas injestor cleaner in yesterday, I will be starting her up in a few minutes and see how she feels.

 

by reving in cold weather you force the ecm to change timing