Idling

[bigwavedave]

Still learning my new 2005 Duramax diesel. I've been told that, after a long trip, I should let the engine idle for about 5 minutes, and that there is an after-market device that can be purchased and installed to do this somewhat automatically. I doesn't seem to me that this should be necessary. Any advice?

[bobo]

Letting the truck idle after each use will let the turbo get some cool air on it and cool the turbo down. I have an egt gauge. It only takes about two minutes even after running the truck hard. What you are doing by idling the truck is getting the turbo components cooled down with 300-400 degree exhaust air. While operating your turbo is being operated by air heated over 1200 degrees at some points. It isn't a bad idea to let it cool off for a minute or two before shutting the truck down. There is a device called a turbo saver that will keep your truck running when ignition is turned off and will shut your truck down automatically when turbo is cooled down. I have this feature on my Viper 160 XV remote start and I use it when my egt gauge is over 400. When I want the truck shut down, I press a button, turn ignition off, and the truck idles for two minutes and shuts off. It should extend the life of my turbo.

[Kennedy]

The idle time thing is primarily after working the engine. In most cases, you have sufficient light load/low RPM operation prior to parking. Turbo timers are neat, but personally, I have a remote start that can act as a timer which to me is a lot more useful.

I do idle my engines for a few minutes prir to leaving when not up to temp, and use my oil psi gauge as a guide in regards to cold weather operation. The LB7 I keep under 80 psi and the LLY, the 90 mark on the OE gauge.