Long term ideling
 

OK whats the low down on ideling a diesel engine? I'm getting conflicting opinions for short runs back and forth with long stop times?????

If you have to idle for more than a minute or two, set the RPM's up to 800 to 1000.

Otherwise shut it down while waiting.

idleing a BIG NO NO for me, i cannot stand just listening to my truck thinking "what was that noise" when i think it doesnt sound right, i idled a few weeks ago while waiting at a customer and i slept about three hours 11-2 during the day and i thought i was gonna cry when i woke up cuz i didnt mean to sleep that long, i heard that idleing your truck up(hitting the cruise up) making it run at higher rpms is just a waist???? what good does it do bumping the RPMS up any

Keeps the oil pressure up, keeps the water circulating better, keeps cylinder temps up so combustion is more complete and raw fuel isn't washing your cylinders, causing piston, ring and liner wear.

But in these days of 3.00 a gallon fuel, shutting it down is a better option, at least when the weather is warm and re starting won't be a problem.

My Cat maint. manual says to Avoid excessive idling, But if you have to idle for long periods to set the rpm's to 1000+
It also say's the engine can burn from .7 gallons per hour to 1.5 gallons per hour at idle.

The way I understand it, it takes 1000 revs to build enough compression to seat the rings... That way your not washing the sleeves with diesel. I myself Never idle under 1200 !

1200 ???? man all i see is dollar signs going out the stack. lol.

OTOH... At my old company, I just couldn't see running the engine this high at idle for the night, so I didn't. After a few months of this, it started drizzling oil out of the seams in the exhaust manifold, and my boss chewed my ass for not running it high enough at night.

The truck I just got into had a history of useing oil, I made a point of no idle @ 650,! 1200 any time the yellow button was pulled, 1200... no more oil cunsumtion.? As far as fuel... I think it's all hyped up, do your own test, idle it, then refuel... Petes always spit fuel at you when their full :lol: I tried it, 1400 rpm, 14 hr's -40 less than 10 gals. Accert 550

well them i guess i'm just lucky then.. when i first bought my truck. i knew nothing about idleing. just that it said on engine not to idle lower than 600.. so i would idle at 6-1/2 700 tops. i have hit 1 mil miles about 4 months ago. never anything done to engine. nothing. still original injectors, e.t.c. still runs very good. 11.1 detroit. should i idle at 1000-1200 or keep it where i kept it for over 7 years now ?

It depends, I don't know much about those 11.1 L detroits but I do know the 12.7L detroits like to idle around 1000 rpms.

Some engines are ok with a lower idle, like volvos. They're designed better so that they don't need a super high idle. Saves on fuel too.

Could be just the smaller engines can handle the "slober" thats what our mechs. call it. We have a M 11 engine in a truck... it's the yard truck :lol:
It's got a bunk, low miles, nice paint, chrome package... 03 ? Yep the yard truck... No offence ment, but we need power...

Yep...slobber is what Cat calls it too in the manual. Plus they say it causes carbon build up.

quote="silvan"]OTOH... At my old company, I just couldn't see running the engine this high at idle for the night, so I didn't. After a few months of this, it started drizzling oil out of the seams in the exhaust manifold, and my boss chewed my ass for not running it high enough at night.[/quote]


1000 is lots

the slober is NOT caused by idling under 1200, it's caused by running for long periods at low idle speed, more specifically; operating with a cold combustion chamber which causes incomplete combustion of fuel

?

What temp does your engine run at while idling?

new(er) engines (first 100,000) are most susceptible to ring seating and cylinder glazing problems. destroyit diesel used to be the ones i saw the most issues with

OTN ; some guys will NEVER experience this problem... well, at least for now

What I was getting at is two separate things on the Volvo:

1) The oil system is designed better, holds better pressure at lower rpms, and doesn't drop when the oil thins out(gets hot). For example, mine holds a steady 60 psi anywhere above 1000 rpms. Below that, even hot idle, doesn't drop below ~35ish.

2) The exhaust valve. It closes, creating a restriction in the exhaust, so that the engine has to work a little harder. This harder work creates a more complete burn.

i forgot that you have a volvo engine... that exhaust brake WILL load the engine and improve cold weather idling temps. does it open/close automatically?

It runs any time the engine is below 170 degrees. It doesn't care how cold it is out. It requires air to run. I guess it doesn't help with normal, at temperature idling. Cold weather performance on the volvos is far superior to any other engine I've ran.

They exhaust brake is also a problem on Volvos. The valve that controls the exhaust brake is $700, and the exhaust brake itself is $2000. I think both of mine need to be changed, they leak air. I might just to a rebuild.

Another thing, you cannot disable them. Well you can, but then you have to live with a code and no, I mean absolutely ZERO jake brake. I guess they did the jakes a little different from most manufacturers.

I have a completely open exhaust system, no baffles. I do have a muffler, but I'd hardly consider it that. Even with that setup, the jake is much quieter then other trucks with full-baffled mufflers.

just got info off of cummins websight. say's idle at lowest prm's possible but never more than 800 i dont know how to put websight here.

Volvo motor does not need to be bumped up at all for idling. The manual and back of visor say the motor has an exhaust valve (i think) that maintains the temp. Yeah Volvo....

I bumped my high idle a bit simply to maintain better oil pressure.

Word of the wise, if you have recently swapped your turbo, DO NOT let your truck idle for excessive amounts of time. I can cause the thrust bearing in the turbo to fail and cause the turbo to leak oil. And if a shop detects that the truck has been idled over a given % of time via the ECM, they will deny warranty!

How do you bump the idle up?
1995 International 9400 w/DD 60 11.7

Just use the cruise control. Set the RPMs where you want and consider it bumped.