My brother in law always lets his truck run for a min or two befor he kills it. He says its what your supost to do with a cummins to let the turbo cool down befor you shut one down. I just wanted to know if tis is true and if so how long should I let it run after I stop befor i shut it down?

And if im just running in the store for a min, is it better to leave my truck running or should I shut it off?

 

Short runs only need about 30 sec to cool enought to be safe. Highway runs are more like 2 minutes. The reason is that the turbo runs way hotter than the oil can stand. The oil flowing thru the turbo has a cooling effect on it. After the engine is shut down the oil is stationary in the turbo and if the turbo is blazing hot the oil cooks into a very tough deposit called coke. Coke will clog the turbo oil passages over time and starve the turbo of oil causing catastropthic failure. Always idle down the engine for at least 30 seconds on short runs.

 

thanks for the info

 

Regarding late model turbo's, rockwithjason is dead on.

The early turbos (before ball-bearing technology kicked in) had Babbitt bearings which were really funny about temps as the material would present with plastic deformities (melting) if not cooled properly.

 

if you go in store just for under five min let it run and after a good drive let it cool for 2 or 3 min

 

thanks guys now I wont be looking for a new turbo

 

"Time to shutdown" is really only applicable if you do not have a pyro...if you do, anything below 300*F is good to shutdown.
Above that, particularly if you're running traditional oils, will resut in "coking" the bearing over time. That in turn results in bearing failure and usually takes the turbo out with it due to lateral and linear runout...nasty...

If you can run even a semi-synthetic you are ahead of the game due to it's ability to handle higher temps with less volatility and higher flash point.

pb....

 

Lets say I just make a quick run down to the store. Never go over 35mph and accellerate gently, would I be fine killing it after say 10-15 seconds.

I always spend the last five minutes in the truck driving very gently so as to let it cool before I get home. Would this be an effective cool down?

 

i would say yes, but the gauge may tell a different story. why short change yourself. are you in that much of a rush where a min isnt worth the costly repair down the road? heck you probably think your boot time on your cpu takes longer each time, lol, j/k

If i had no gauges, "I" would do 1min around town normal driving. and 2-3 min normal highway.

When i tow up a long grade and then happen to stop or need fuel i try to leave it running. but if im going into a store after that pull i wait till it hits 300 then wait another min to actually circulate at that temp.

jiMMy

 

Along the lines of this topic...
I am a volunteer FireFighter, I only live about 1 mile from the station. So if I get a call i'm not going all that far. And I really can't sit in the truck and wait a minute or two to let the truck run. A buddy of mine told me that basically as i'm pulling into the lot just shift to neutral and coast on it and that would give it plenty of time to cool down. Would that be ok, or should I possibly look into getting one of those cool down timers, or a remote start that has a run option?

 

N = no load on tehmotor so that should do it. but depends on how fast your getting to the scene and how hard you are on the truckin that time frame.

jiMMy

 

I'm in the same boat.

Thinking real hard about the cool-down timer as I don't hold back running 10/18 traffic.

http://www.buiescreekfire.com/

 

I'm also looking into remote starters with run options, it will essentially do the same thing, and I would like a remote start anyhow. A buddy of mine has a remote start on his 24valve, and it has an option that if he its the button with the truck running he can take the key out and it will remain running, but not driveable for a progamable amount of time, in 5 minute programmed incroments, I think that is the way to go myself. As soon as tones drop I can start the truck, get my shoes on or what not, head out to the truck, roll up to the station, hit the remote start button, lock it up and leave it.

 

Bushy, If you dont mind me asking are you an auto trans or a standerd?

 

and I see you have 373.4RWHP how much TQ are you hitting to the ground?