Leaving Diesel Run

[want-a-be]

Should you leave a diesel run for awhile before shutting down, if so how long should you leave it run? I have heard you should leave it run to let the turbo cool down but what if you do not have a turbo?
Thanks for all comments

[WILDEBILL308]

DanTheRVMan wrote:

wolfe10 wrote:

2gypsies wrote:
We found that by the time you slowed way down entering a campground and then drove to your spot and parked, that was sufficient time for shutting down.

The same goes for when you leave, have everything stored THEN start it up, pull in the slides and by the time you get to the highway you're good to go.

EXACTLY the same concept as on start-up. Common sense is needed.

As you say, if in a CG and you are going to drive out of the CG and a mile or so at low speeds "you are free to move about the country" as soon as air pressure is built.

After spending the night at a Flying J at the entrance ramp to the freeway, then idle (high idle-- like 1000 RPM please) until engine coolant temperature is 150 degrees F or so.

There is a reason that there is something on top of our NECKS.

I find engine to hot to turn off when I get to a fuel pump many times even though slowed way down entering truck stop. How long it takes to cool to 180F varies a LOT. Similarly rest areas for lunch. Shopping stops, etc. It is not as simple as CG example above

A good guideline of time or temp for shutting off would help many imo. I use temp

Air up and good to go I agree with. What surprised me was camp frieghtliner said no full throttle until 180 F also (do not ask me to defend the basis for this requirement I'm just repeating frieghtliner recommendation). I hit free way on ramps below 180 F lots of time

I use the EGT temperature as a guide when to shut off. I like to see it below 450 before shutting down. My water temperature seldom goes above the thermostat regulated temp, unless pulling a long hill.
Bill

[Kayteg1]

Each engine is different.
My old 2-cycle Detroit doesn't need much of warm up. I have quiet electric compressor for airing up and in California weather I drive my coach few seconds after starting the engine.
My 2007 Powerstroke in pickup has electronic controls that even at 100F make the engine sluggish and will hold low gear for a mile.
I newer observe the warm up for moving. Just be gentle with throttle.
Even living in 4 seasons I would drive my cars right after starting even at single digits temperatures. Old carburetor engines would hesitate when cold and gas pedal was pushed, so I would start rolling on idle if the situation allow.
Engine under the load warms up much faster.
If you can't risk slow rolling with cold engine, turning headlights on while idling will speed up warm up.

[DanTheRVMan]

wolfe10 wrote:

2gypsies wrote:
We found that by the time you slowed way down entering a campground and then drove to your spot and parked, that was sufficient time for shutting down.

The same goes for when you leave, have everything stored THEN start it up, pull in the slides and by the time you get to the highway you're good to go.

EXACTLY the same concept as on start-up. Common sense is needed.

As you say, if in a CG and you are going to drive out of the CG and a mile or so at low speeds "you are free to move about the country" as soon as air pressure is built.

After spending the night at a Flying J at the entrance ramp to the freeway, then idle (high idle-- like 1000 RPM please) until engine coolant temperature is 150 degrees F or so.

There is a reason that there is something on top of our NECKS.

I find engine to hot to turn off when I get to a fuel pump many times even though slowed way down entering truck stop. How long it takes to cool to 180F varies a LOT. Similarly rest areas for lunch. Shopping stops, etc. It is not as simple as CG example above

A good guideline of time or temp for shutting off would help many imo. I use temp

Air up and good to go I agree with. What surprised me was camp frieghtliner said no full throttle until 180 F also (do not ask me to defend the basis for this requirement I'm just repeating frieghtliner recommendation). I hit free way on ramps below 180 F lots of time

[Chum_lee]

Off topic but appropriate. As a retired engineer and a former turbo charged Audi (gas) owner I can assure you that after many premature turbo failures, AudiAG installed an electric after run turbo coolant circulation system which also ran in conjunction with the electric radiator fan. Promptly, premature turbo failures dropped to close to nil. That was back in the days (early 80's) where turbos were the newest latest greatest thing and a learning curve needed to be established. Heck, back then even high performance snow skis were labeled . . . . "turbo!"

Chum lee

[mabynack]

The logic is that it won't hurt anything to let it idle for a couple of minutes and could save you expensive repairs over the long run.

[Mike_Hohnstein]

A gasser with out a turbo should be idled for a few minutes after high way service, the exhaust manifolds are well served by cooling down gradually. Consider all the complaints regarding exhaust manifold leaks on forum.

[creeper]

Let them idle for a little while to cool down, too long and you could end up with wet stacking issues if you do it too often.

[wolfe10]

2gypsies wrote:
We found that by the time you slowed way down entering a campground and then drove to your spot and parked, that was sufficient time for shutting down.

The same goes for when you leave, have everything stored THEN start it up, pull in the slides and by the time you get to the highway you're good to go.

EXACTLY the same concept as on start-up. Common sense is needed.

As you say, if in a CG and you are going to drive out of the CG and a mile or so at low speeds "you are free to move about the country" as soon as air pressure is built.

After spending the night at a Flying J at the entrance ramp to the freeway, then idle (high idle-- like 1000 RPM please) until engine coolant temperature is 150 degrees F or so.

There is a reason that there is something on top of our NECKS.

[2gypsies1]

We found that by the time you slowed way down entering a campground and then drove to your spot and parked, that was sufficient time for shutting down.

The same goes for when you leave, have everything stored THEN start it up, pull in the slides and by the time you get to the highway you're good to go.

[down_home]

Let it idle for five minutes. Even if it was a gas engine running a turbo I would let it cool down.
The only cooling to the turbo is oil. There have been some turbos with cooling jackets for coolant but even then you would let it idle a bi to cool down.
Every diesel engine in motor homes today has tubos, unless someone has sneaked in. Maybe someone is using superchargers but I don't know about it.
An older mh might have a Detroit 2 cycle 471 or 671.

[J-Rooster]

I'm a retired truckdriver that drove mostly CAT engines and I would let them idle while doing my log book then shut the engine off.

[Kayteg1]

Cloud Dancer wrote:
Does it hurt anything to always let the turbo(ed) engine run at idle for 5 minutes before shut down?
.

Yes. Environment. (not to mention owner pocket)
In California they actually made a law forbidding idling.
Wolfe is making good point about thinking.
I was hauling heavy with my manual diesel pickup in the past, but when I was coming to rest area, I would switch to N about 1/2 mile before exit. By the time I rolled down to stop the engine already had couple of minutes of low rpm with good air flow.
Not all turbos require cooling.
We drive turbodiesels in Mercedes for over 20 years and cooling them down was never an issue.
You can also buy a module that will keep engine running for few minutes after removing key from ignition.
My son bought gasoline, sport car Mitsubishi where PO installed such module to prolong turbo on it. Sure made some strange looks when you close the door and walk away from car with engine running.
Than some engines do have electric coolant circulation pump that will even engine hot spots for few minutes after shut down.

[WILDEBILL308]

Cloud Dancer wrote:
Does it hurt anything to always let the turbo(ed) engine run at idle for 5 minutes before shut down?
BTW the diesel engine that powers my ONAN generator does not have a turbo. That one I simply shut down right after it's been running at normal speed.

If you read your owners manual it will tell you to let it idle under no load for 3-5 minuets before shutting down.
Bill

[WILDEBILL308]

want-a-be wrote:
Should you leave a diesel run for awhile before shutting down, if so how long should you leave it run? I have heard you should leave it run to let the turbo cool down but what if you do not have a turbo?
Thanks for all comments

Help me understand your question. What diesel engine are you talking about? Your coach has a turbo on the engine and you should let it cool down as others have commented. Now your generator doesn't have a turbo. You should follow the instructions in the owners manual and let it run for a while with no load to cool down. My book says 3-5 min with no load.
On my coach I liked to get my EGT temps under 450degrees.Most of the time just getting into a camp ground is enough time. If stopping at a rest stop or for fuel I may have to wait 3-7 min depending on ambient temperatures.
Bill