Extended Idle How Long Is Too Long????

[cwarner]

Another thing to worry about when idling for long periods of time (so I was told) , is in an automatic trans the pump is not circulating trans fluid , unless it is in neutral or drive. This can cause some problems with the trans internals.

Anyone else hear of this ?

 

[B.W.T.]

Idle to long? Cold morning starts? Warm up? One would think that on cold mornings let things warm up before operation so not to have excessive oil pressure and a cold cab. It takes my truck a good 15-20 min to bring water temp. to normal (depending on temp. ) Since you talkabout higher idle what would one suggest.



A idler stick from the seat to the pedal

I don't have an Engine-brake but for load would putting the Emergency Brake on and setting it in gear do the same as in for setting Engine load.



I don't want to harm my new beast and would like to keep it around. Any suggestion would be good THANX

 

[illflem]

Don't worry about damage to the trans, though you can warm the fluid in N, it will shift into OD sooner then.



Bring your rpms up to 1200 with a stick or whatever, it can run all day with no damage. It may be cheaper to plug in the block heater all night or for three hours with a timer for faster warm up than letting it run for 15 minutes depending on what you pay for power.

 

[WadePatton]

I like the stick.



What RPM should I set it for?



I'll plug it in _if_ it ever gets into the 30's.

 

[WKener]

In the cold mornings here in Steamboat, I use my long-handled ice scraper for the high-idle feature

Stick it down on the pedal, and then lift the center console to rest on top, apply enough pressure to bring rpms to 1200-1300 and it works flawlessly! I don't let it sit like this too long, just enough to warm it a little, and I'm off.

If I need to idle for an extended period of time, I will use the ice scraper method, which will bring egt's up to about 350-375* at ~1250rpm. I have not run into any problems yet...

Wes

 

[Mingoglia]

Is it the general agreement that EGT is the best measure of determining if the engine is running within a safe temperature for idling? For example, if one can keep their EGT above 300 degrees (post) can we assume that the engine isn't having a problem generating enough heat for safe operation?... I used to assume having the engine temperature between 180-190 was safe but I can definately see how EGT might be a better "yard stick"...



Mike

 

[skerkvliet]

In my opion, (yeah, another one) long idle periods don't hurt a thing once the engine is up to normal operating temps. I like to let mine warm up 5-10 mins at cold start up and then take it easy until the thermostat opens. You can tell when this happens if you watch the water temp - it will go a little past the normal "warmed - up" the first time after the engine completely cooled off. After that it can idle all day as long as you warm it up to normal operating temps before you shut down.



I base this on oil analysis results. I run a by-pass filter system and sample my oil every 15,000 miles. My soot levels and fuel dilution are <. 01. I'm sure that I get some fuel dilution that boils off with a good pull. The additive package in the oil remains intact and my wear metals are very low as well.



I say let 'er idle if you're gona get 'er wrmed up good on the way home.



Steve

 

[b.ferrara]

the two guys who talked about oil contamination & his jd tractor

hit right on the money. Idling for long periods of time causes

the diesel fuel to mix with the eng oil never bothered to find out why or how, just know thats what happens folow their advice

and stick with the 5 min rule.

 

[KEarnest]

for a slick high-idle device

Check out the High-Idler Kit at Practical Solutions Diesel Products



It has an in-cab adjuster and can idle up to about 1700-1800rpm I believe.

 

[dalton4]

Night of 20 Feb 02, I idled mine for 13 hours at Tok, AK using a rpm setting of 1150-1200. I was very pleased to have a warm cab when the Lance camper furnace failed at 11:10 pm due to not enough propane boil off. Night temp only got down to -35F.



In case you may be wondering about fuel usage while idling at 1200 rpms ... I estimate the above to have used about six gallons.



Jerry

 

[David Oxland]

Another factor in this idling thing is that the rate of injection is slow. Think about the injection pump at tickover. The plungers are at much reduced velocity and therefore so is the injection pressure.

Injection pressure is not controlled by the injector. The injector mainly regulates the pressure at which the needle lifts but after the needle has lifted the pressure continues to rise viciously giving the good atomization required for complete combustion. This is where common rail systems have an advantage in that they start and stop their injection with this pressure mostly at a constant high.

So with jerk pump type injection, poorer atomization, combustion, and consequent washdown can occur.

 

[pkennedy]

After many years of living North of the 49th and owning many diesels of different makes and sizes an established rule of thumb has been recognized. You have to first realize if its running it's wearing out but in order to prevent excessive wear engine must run at 160 deg or more for complete fuel combustion (1st gen 180+) next never leave engine idle below operating oil pressure (bearing surfaces rely on pressure and circulation). One of the most important things to remember is that your Heater is a heat exchanger (radiator) leave temp high but fan LOW when idling and as temp drops idle speed may have to be increased to compensate ie; mine idles at 1800-2200 at -40. Serious signs of poor combustion (slobbering) are as stated diesel in oil (cylinder wall washing) and when it's really cold shiny tar like wax at the end of the exhaust pipe, driving under these conditions will kill your Cummins. The manufacturers don't like it but up here but my CTD is completely covered at -10 F.

 

[illflem]

One thing I've found when warming the rig at high idle in sub zero temps is that it warms much faster with the fan on high with the selector on Recirc. The heater core acts as a mini radiator, rather than pulling cold air outside air though it having the gradually warming recirculating cab air instead speeds coolant warm-up. I've come back to my truck high idling after less than 10 minutes in -20° weather to a cab that feels like it's over 100°. When driving in sub-zero temps I've watched my temp gauge dive instantly by just switching from Recirc to outside air. My feeling is that you could probably get by without any radiator at all when it's really cold, the heater core alone is enough to keep the coolant temp down.

 

[pkennedy]

I will agree that the recirculation method increases cab warm up time unfortunately it also retains all the moisture in the cab and takes longer to unfog the windows. At -10 F and Below I still leave my fan on low because my truck idles all day and my operating temperature in my engine stays above 180, once Iam moving there is no problem achieving a comfortable cab temperature. I traded my 91 CTD in with 400,000 KM and replaced only 1 oil cooler and one thermostat, on my 01 the computor high idle refuses to function so I installed a manual throttle cable to the foot feed which always works.

 

[WadePatton]

Use what's handy.

I picked up a piece of black plastic pipe--outta the yard--bachelor here. Cut it two or three times to make a High Idle Stick.



The next one I'll cut longer for the armrest method. I'm using the seat, sometimes it takes a couple of adjustments.

 

[drees1]

Liner Glazing, too

One thing not mentioned yet is the effect of cylinder liner glazing due to extended idleing. CAT is very susseptable to this problem and MUST be idled up if to be run for a while. I have seen countless rebuilds at low miles in our shop due to excessive ideling. The ECM readouts frequently show 50% or more time idle. The pistone rings are worn, oil consumption is up and there is no crosshatch left on the bores. Idle up to 1000 or so and everything is fine.



Now that is for 3406 and C10/12 mostly. I think the glazing problem is more model specific. And many engine built for ineer city use are more tolerant of idling. International advertises the TD444 as capable of idleing long periods. (What else can it do? ) I suspect our Cummins 5. 9 is also designed for more ideling than the over road trucks, too. But why risk anything, just make it run 1100 or more and you can have idleing and no worries.



The Cat engines should go 800,000 to 1Million, and we saw many shot at 350,000 that were over idled. How many of us extend the idle on our 5. 9's and have over 350,000? What I'm saying is that we may not accumulate enough mileage to even get to the point where it is a problem. But me, I'm treating mine like it will go the million.



Our stock engines have such good atomization due to emissions that if warmed up, should not wash a cylinder. Bombed with 370's may be another story.



Doug Rees