Letting truck idle

Grit dog wrote:

Hannibal wrote:

Lynnmor wrote:
Right from the Owners Manual:

SWITCHING OFF THE ENGINE
Turn the ignition to the off position.
To prolong engine life (any timey after extended high
speed, high ambient temperature, or high GVW/GCW
operation, such as heavy loads or heavy trailers),
it is recommended that a hot engine be idled for
3-5 minutes.

This allows the turbocharged engine to cool down.

All four of my Cummins Rams had pyrometers with the probes in the exhaust elbow where it belongs. All four were at safe shutdown temp any time I stopped after towing or high speed operation. A quick stop at the top of a grade might necessitate a cool down period but convenience store and campground idlers are just playing big rig and looking foolish.

Agreed, except for pyro location. Pre turbo is better for monitoring high temps under load and heavy fueling.

My four Cummins engines were bone stock. My only concern was shutdown temps where the post turbo elbow spot pre dimpled by Cummins gives the best temperature of the turbo. The turbo can soak up a lot of heat and retain it while pre turbo temps may come down sooner. If I had a modified Cummins, I'd probably have had both locations monitored.:C

My owner's manual has idle cool-down times for my new CTD depending on how hard it has been pulling. recommended cool down is 5 minutes in some cases.

Hannibal wrote:

Terryallan wrote:
Some folks just like to think they are wheeling a big truck, and want you to think so as well.

Usually the same ones who drive around with their towing mirrors out when they're not towing anything.

Cummins has never condoned extended idling. It has never been good for a diesel or gas engine to idle for extended periods.

Hey I resemble that remark about tow mirrors!! lol. With my DRW I usually keep em flipped up..

I will let ours run, the outside heat is insane this year. Once ya get going again just step on it and let the turbo spool up and blow it out.

:)

Hannibal wrote:

Lynnmor wrote:
Right from the Owners Manual:

SWITCHING OFF THE ENGINE
Turn the ignition to the off position.
To prolong engine life (any timey after extended high
speed, high ambient temperature, or high GVW/GCW
operation, such as heavy loads or heavy trailers),
it is recommended that a hot engine be idled for
3-5 minutes.

This allows the turbocharged engine to cool down.

All four of my Cummins Rams had pyrometers with the probes in the exhaust elbow where it belongs. All four were at safe shutdown temp any time I stopped after towing or high speed operation. A quick stop at the top of a grade might necessitate a cool down period but convenience store and campground idlers are just playing big rig and looking foolish.

Agreed, except for pyro location. Pre turbo is better for monitoring high temps under load and heavy fueling.

salem wrote:
A friend of mine always lets his 2500 diesel idle while he makes a short run into the post office, store for a quick soda, etc. He says the salesman told him that starting and restarting a diesel was the worst thing you can do. Of course he locks it up, but I have never heard of this. Is this common practice?

I don't know about hurting the engine but it's putting undue wear on everything that runs on the fan belt.

Lynnmor wrote:
Right from the Owners Manual:

SWITCHING OFF THE ENGINE
Turn the ignition to the off position.
To prolong engine life (any timey after extended high
speed, high ambient temperature, or high GVW/GCW
operation, such as heavy loads or heavy trailers),
it is recommended that a hot engine be idled for
3-5 minutes.

This allows the turbocharged engine to cool down.

All four of my Cummins Rams had pyrometers with the probes in the exhaust elbow where it belongs. All four were at safe shutdown temp any time I stopped after towing or high speed operation. A quick stop at the top of a grade might necessitate a cool down period but convenience store and campground idlers are just playing big rig and looking foolish.

Doesn't this thread apply to the neighbor who warms up his truck to drive a couple of blocks for a pack of smokes and then does a cool down idle after he gets home?

Lynnmor wrote:
Right from the Owners Manual:

SWITCHING OFF THE ENGINE
Turn the ignition to the off position.
To prolong engine life (especially after extended high
speed, high ambient temperature, or high GVW/GCW
operation, such as heavy loads or heavy trailers),
it is recommended that a hot engine be idled for
3-5 minutes.

This allows the turbocharged engine to cool down.

Good old owners manual, intentionally vague, so as to not to commit to anything that could be argued.

What's considered a "high speed?" If a vehicle is designed and built to operate on public roadways, including expressways, then 80mph or 120kph shouldn't be considered a high speed, it should be considered a normal operating speed. So what's a high speed then, running at the rpm redline, 100mph, 150mph?

What's a "heavy load", 50 pct of the max GCWR, 100, 150 percent?

Right from the Owners Manual:

SWITCHING OFF THE ENGINE
Turn the ignition to the off position.
To prolong engine life (especially after extended high
speed, high ambient temperature, or high GVW/GCW
operation, such as heavy loads or heavy trailers),
it is recommended that a hot engine be idled for
3-5 minutes.

This allows the turbocharged engine to cool down.