starting up and shutting off question

[merrick4]

So now I'm watching the idling as I have my own truck. When I stop the truck gets turned off, even if it's only for 5 minutes. I have an APU so excessive idling is not going to be an issue for me.

Say I shut the truck off for 5 minutes or so, do I just crank it back up and go or do I have to let it run for a minute? Also I was told today that I shouldn't shut it right down but let the engine cool down for a moment. So if that is true then if I'm only going to be off for a few minutes then maybe I shouldn't even shut it off.

Thanks

[allan5oh]

The only reason to "cool down" the engine is to reduce exhaust temps, so that the oil in your turbo doesn't "coke". You want to keep that oil moving until the EGT's come down to a reasonable temp.

95% of the time this isn't necessary, because it will be cooled down from backing into the spot, moving around the truck stop, etc..

If your engine is warm(fully warmed up within the last 3-4 hours), fire it up, wait about 5 seconds, and just take it easy on the first few gears(you should do this anyways).

In winter, I let it idle for about 2-3 minutes from cold, although I do have an espar engine heater that I use liberally. In winter I really try to take it easy unless the engine is fully warmed up. Especially first thing in the morning when the only way you can warm up the tranny/diffs is by driving. You can blow seals if you instantly get up to speed on a really cold day.

[merrick4]

Thanks Allan. Actually this APU has a feature that it doesn't let the engine get too cold. Hopefully I won't spend too much time in the cold, I didn't move to Florida from New England to spend time in the cold

Thanks again

[Doghouse]

Great advice from allan,
Just watch your temp. get used to what it is at idle, and at cruising speed.
Chances are if you have not just pulled a hill, you can just shut it down when you park, kick on the APU and go to sleep.
I would recommend a diesel fired engine heater, they warm the engine coolant more efficiently (tahn the plug in electric units) and they are programmable so you can have it start warming an hour before your ready to do your PTI and hit the road.
Also you can program it to come on and shut of at intervals when your away from the truck for a day of so.
Cold weather will not be anywhere as bad on your truck if you can keep that engine warm when its cold out.
Oh,..wait a minute,..does your APU run off the main engine coolant?

[merrick4]

Great advice from allan,
Just watch your temp. get used to what it is at idle, and at cruising speed.
Chances are if you have not just pulled a hill, you can just shut it down when you park, kick on the APU and go to sleep.
I would recommend a diesel fired engine heater, they warm the engine coolant more efficiently (tahn the plug in electric units) and they are programmable so you can have it start warming an hour before your ready to do your PTI and hit the road.
Also you can program it to come on and shut of at intervals when your away from the truck for a day of so.
Cold weather will not be anywhere as bad on your truck if you can keep that engine warm when its cold out.
Oh,..wait a minute,..does your APU run off the main engine coolant?

Yes Doghouse, the Apu does run off the main engine coolant. Also, I forget where you wrote it, but you were right about the APU and the outlet it has. When I use the microwave with the inverter it dims as it's pulling the power, when I plugged it into the APU plug it ran just like it would if I was at home. I tell you, I am very pleased with this thing so far. I don't know if I mentioned it before but it's a Comfort Pro by Carrier.

Thanks again for all your advice.

[yoopr]

I always Idled it down for 5 minutes or so before shutting down the engine.

[solo379]

I also, don't believe, that shutting down, if you only stop for 5-10 minutes, will benefit you in any way!

[allan5oh]

Nah, even if you shut down for 5-10 minutes you're saving fuel and wear and tear.

Idling is about the worst thing you can do to diesels.

[solo379]

Idling is about the worst thing you can do to diesels.

I've always believed, that the most stress on the engine, is coming from the start ups, even if it's not "cold"! Not to mention the starter, batteries and therefore alternator...! :wink:

[allan5oh]

Idling creates massive amounts of sulfuric acid. This acid eats cylinder rings and walls.

"hot starts" don't stress your electrical system at all. Lack of maintenance definitely does.

Most trucks nowadays don't fire for 3-4 revolutions anyways, more then enough to get pressure to the bearings.

[Doghouse]

Thats great, your APU will keep your engine warm and ready during the winter.
Good luck out there,...see ya soon :wink:

[roadranger]

Idling creates massive amounts of sulfuric acid. This acid eats cylinder rings and walls.

Low (and now ultralow) sulfer diesel fuel has made that much less a problem than in the past. Also the oil will neutralize a certain amount of acid. The new oils actually have less ability to do this as it isn't much needed with ULSD. Idling does use up the additives in the oil faster and loads it with soot.

[bob h]

Idling creates massive amounts of sulfuric acid. This acid eats cylinder rings and walls.

Low (and now ultralow) sulfer diesel fuel has made that much less a problem than in the past. Also the oil will neutralize a certain amount of acid. The new oils actually have less ability to do this as it isn't much needed with ULSD. Idling does use up the additives in the oil faster and loads it with soot.

egr... and now for '07, 30% more egr is what raises the level of crankcase acids...... why do you think the oil changed in '02..... and again in '07? from api-ch to ci and now to cj. the lube oil spec with the least (if any) change was cat's as they did not use egr