Im new to this forum and to diesels. This site has helped me understand what I am needing to know. I have a 2001 F-250 psd with a k&n and straightpipe, no muffler, no converter. When it is extremely cold outside, like in the single digits, and I dont have my truck plugged in when I start the truck, if it starts, it seems like it is only hitting on half the cylinders for a while until it clears out. It then idles at about 700rpm for about 2 minutes the it will idle up to 1100 rpm until I hit the brake or gas pedal. The exhaust sounds like a jet plane is taking off when it idles high. My main concern is, is this normal for these trucks to do this.

 

Yep that's normal. The truck will rev up to help heat up. The noise you hear is the exhaust back pressure valve (ebpv) closing to restrict the exhaust, also to help heat up the motor. For the system to work the parking brake must be on and or have the trans in park and the air temp must be pretty cold - 40 degrees? Anyways do a search under ebpv and you can read up on it.

 

Another tip for you:

If you want it to start easier and keep from running as rough on a cold morning, let your glow plugs cycle longer. Most new diesel owners will see the glow plug light go off and immediately crank. However if it's really cold out, your glow plugs haven't been on long enough to really heat the cylinders up enough. When you turn the key to the "on" position, your glow plugs will run for up to 2 minutes even after the light has gone off. On some really cold mornings, I'll turn the key to "on" let it sit for almost 2 minutes, turn to "off", turn back to "on" let it sit for another 30 seconds to a minute, then crank up. Doing it this way my truck always cranks on the very first try and immediately idles smooth, even if the temps are in the low teens. I have never plugged my block heater in.

Hope this helps. Keep reading this site, lots of good info awaits you.