I asked this question last winter, no responses.

In the winter months, driving truck on highway for 60 mins., pull on off ramp, sitting at light. My idle will be close to 1000 rpms. If i shut it down then start it back up, the idle will be normal. But this happens like clock work...only in cold weather. Truck is so loud idling so high at a light. Is it suppose to be that way? I haven't heard of other members saying this.

Anyone?

 

You know i had the same question I hope somebody answer's this question.

 

Have you tried tapping the pedel to see if it goes back to normal idle? If it doesn't then the high idle isn't the problem. It shouldn't be the high idle if you have be driving for 60 mins. because the engine would be warm.

 

Yeah, I would try tapping the pedal...but I agree the high idle should only come on if you truck is really really cold. I know mine only comes on in the morning when I park outside but after I drive for a while it no longer comes on.

 

If it's similar to the new ones, the high idle is activated by manifold temperature. What you describe is VERY common in cold weather. Running down the highway, you build some heat, but slow down and you engine temp plummets like a 16 ton weight. Watch your temp gauge next time it does it, I bet you'll see it's dropped way down. It should go off as soon as you touch the brake. You got to keep in mind that the cooling system on these things is designed for heavy pulling in hot weather. It's absolute overkill in winter weather. I've actually had mine cool off enough for the grid heater to come back on, in the same situation you describe.

 

the idle does not come down if I tap brake. I'm at a traffic light with my foot Standing on the brake. Idle does not change. if I tap it or stand on it. ??

 

wrong pedal to tap