To Idle or Not to Idle? If So, How Long?

[putneyflash@...]

In the heavy equipment field we always said 5 minute cool down, that gives the cooling system time to cool down, but also the turbocharge is probability running anywhere from 80000-100000 rpms if the engine is hot and been pulling, the 5 minutes gives the turbo time to spool down and will stop spinning when the engine is shut off, if you shut down hot ,the turbo can spin (without cooling oil) for 3- 4 minutes.

Just my two cents worth

--
RE

-------------- Original message from "Ryan Wright" : --------------

My owner's manual for the 8V92 said something about "Don't idle; turn
off the engine when not driving as it wastes fuel." I adhere to it,
but I do allow a brief cool down period to get the oil temp around 200
before shutting down. That normally takes less than a couple of
minutes.

During normal city driving my oil temp stays around 200 degrees. It
runs 215-230 degrees or so on the open freeway, especially climbing a
grade. I high idle the engine after stopping if the oil temperature is
much above 200, and turn things off around 200 give or take a few
degrees. Note that this only occurs RIGHT after pulling off the
freeway and stopping, such as a rest area. If I have to drive through
town a bit, or around a parking lot, etc, by the time I get parked the
temp has already come down and I just shut the engine off without
waiting.

However, in any case there should be no need to high idle for more
than a few minutes. If I'm just taking a quick break - run to the
bathroom and grab a drink, then get back on the road - I leave the
engine running. If I'm going to be 10-15 minutes or more, I shut it
down once oil temp is around 200.

-Ryan
'86 PT-40 8V92

On Wed, Oct 29, 2008 at 4:08 AM, Jack and Liz Pearce
<"jacklizpearce%40gmail.com"> wrote:
> Howdy, Y'all.
> Puleeze settle this "discussion" that Jack and I are having.
>
> Question #1:
> Jack says the normal oil temperature is 230 degrees. Jack was told toturn
> the engine off after the oil temp gets down to 200 degrees. Thenone can turn
> off the engine without damaging the turbocharger. Is thistrue for our 8v92?
>
> Question #2:
> When we stop at a rest area to have lunch or for Jack to rest, I wantto turn
> off the engine and not burn that expensive diesel. What doesthe oil temp
> have to be, before we turn off the engine?
>
> TIA,
> Liz
>
> __________________
> Regards,
>
> Jack and Liz Pearce
>
> Fulltiming in a 1993 WLWB
> Summering in Buena Vista, CO
>