I started my 1996 2500 up and let it idle for like 10 minutes this morning and it was about 40 degree out. When I went to drive it I noticed a good amount of white/gray smoke exiting the tailpipe. After 3 minutes or so it stopped. It still has summer blend in it. I then put about 300 miles on her today with no other smoking. Temp gauge normal. I filled her up with i'm guessing a winter blend. The truck is running 10-15 degree warmer at full throttle and normal temps at an idle. Although still staying below 190 degrees over all. Sound like anything to worry about ?

Thanks !

 

Letting it idle does not build enough heat to combust completely. Thats where your smoke is coming from. Do yourself and you truck a favour and cut the idling, no need to idle it at the temps you're at.

As for the temp difference, I assume you're talking about coolant temperatures? I can't see different fuels causing a rise or fall in temp. My truck runs at 180-185F on the highway whether its +35C or -35C, although when I hit an off ramp and coast, the coolant will drop quite a bit when its -30 out.

 

If you have to let it idle I use a piece of wood cut to fit between my seat and throttle pedal, and run my rpm up to 1300.

 

Thanks guys !