2nd Gen Non-Engine/Transmission idleing for prolonged time

[MSnow]

The owners manual say's "prolonged idleing will cause engine damage". I know that if you idle for too long, unburned fuel can get into your oil. How long is to long to idle? What's the cost of parts and labor for a high idle?

 

[av8r]

Hand throttle

I purchased a twist-lock cable (similar to a manual choke cable) from the local parts store for $20 and put it through the useless hole next to the radio, the other end in a 1/8th hole in the top of the fuel pedal lever. Whenever I have to idle more than 2-3 minutes or warm up in the winter I idle it up to about 1200 rpm and let her go. I have been told by a Cummins tech this would be fine and cause no damage.

 

[DavidGardner]

Seems to me I read that Cummins recomends no longer than 10 minutes. I have been stuck in traffic on the mountain passes before and had to keep the trk running for heat in the cab. I just manually held the go pedal down at 1200 rpms while I waited for the road to clear. Dont know if that was sufficient or not but figured it was better than just letting it idle at 750 rpm.

 

[bmoeller]

I did the same as Av8r. Works great.

 

[y-knot]

You know I just don't care what Dodge has to say on the subject. I have always just let it idle when needed and have never had any problems. I do not let it idle over night or anything, but I have gone as long as 2-3 hours. I have never gotten any diesel fuel in the oil, nor have I had any adverse reactions to the extended idling. In the summer months I normally let it idle with the AC on to keep the cab and dog cool. And in the winter months I let her idle to keep everything warm and toasty. I know many on here will take offense to my idling practices, but I do not care, I see no reason to worry about it. At work it is very common to start the equipment first thing in the mourning, and let it run all day in the winter time. It keeps the hydraulics warm and the machine ready to work, several pieces have the Cummins 4 cylinder engine in them. With our engine, it is probably smart to block most of the radiator opening in the winter, so the engine stays up in the 180 degree range. Keeping them warm will go along way in keeping them clean (inside).

 

[cmills]

ideling

I had about 2,600hrs idle time out of 5,700 total hrs on my truck when I had to have it rebuilt at 192,000 miles. the rings were stuck on the #6 cylinder which they said was due to a bad valve guide and too much idle time. I always let my truck idle alot, especially in the winter time when we are doing snow plowing. Now I'm trying to cut back on the idle time.

 

[av8r]

seriously...

y-knot: I put the hand throttle on because one cold winter day (-10°) I let my warm truck idle (700 rpm +/-) for a little over an hour while working in the garage. When I returned to the truck it was idling stone cold. No heat, running rough, no temp on the gauge. This is called "super cooling" according to my Cummins tech friend. He told me that there is so little fuel needed to idle these motors that they can't sustain their internal heat and the cyllinder oiling can be comprimised. I was told 1200 rpm will use enough fuel to keep it warm.

 

[cmills]

idleing

I kinda have mixed feelings about this, due to the fact when at work we would let excavators and skid steers and other equipment idle for hours in the winter time like y-knot said to keep them somewhat warm and the hydraulics warm, we did this and didn't have any problems, also our farm tractors get tons of idle time also, then I go and have these problems with my truck. So I don't know what to think.

 

[Vaughn MacKenzie]

There's a big difference between idling a cold engine in the winter versus one that's already warmed up in mild or hot weather. Once thoroughly warmed up you should be able to idle quite a bit with no harm provided the weather isn't really cold.



cmills as I understand it our B-series Cummins engines are more prone to the effects of cold weather idling compared to some of the others, for whatever reason.



For those who have to idle in cold I'd cover up a lot of the radiator and idle up, and don't ever do it unless the engine was fully warmed to begin with. And then when you do drive it, give the engine a good workout to build heat and burn the crud outa there.



Vaughn

 

[HBarlow]

This is not exactly on topic but is related to the discussion. I bought a Practical Solutions High-Idle kit soon after buying my truck. It is a good product and I'm not criticising it. I already had an exhaust brake which was installed by the selling dealer before I took delivery. Later I had gauges installed which allowed me to see the actual results. Increasing idle rpm to 1200 or so with the High-Idler causes very little rise in EGT. Engaging the exhaust brake will almost immediately bring EGT up to around 400°.



Harvey

 

[RCook]

We have lots of discussion about extended idling and very low power operation amongst us boaters as well. I have a Volvo Penta KAD44, an electronic 24-valve 260 hp diesel somewhat like my ISB Cummins except an even higher power to displacement ratio.



It's absolutely clear that it's not good to idle my 44 for much longer than 10 minutes or so, even if it has already been thoroughly warmed up. It just gets too cold. I understand that temperatures in various places in the engine become uneven when it does this, that it's more prone to carboning up, and I'm not sure what all else. Numerous Volvo mechanics have told me DO NOT IDLE IT (for very long), especially before it is thoroughly broken in.



Seems to me from all I've heard that the higher-revving higher-powered (for their displacement) diesels have more trouble with this than many older lower powered ones. Maybe their cooling systems are so effective at higher power levels that they over-cool at very low levels of power.



I suspect you can tell by simply paying attention to the temperature. If it gets much below 180 degrees, you've been idling it too long, according to my sources.

 

[RustyJC]

According to Cummins, the problem with extended idling is that the 24 valve engines have more efficient valve stem/guide cooling. This results in excessively low exhaust valve stem/guide temperatures during idling conditions which causes formation of varnish and carbon on the stem/guide. This can lead to valve sticking and bent pushrods (or push tubes, as Cummins calls them).



If I have to idle the truck for extended periods, I'll engage the exhaust brake to (1. ) hasten engine warm-up and (2. ) keep EGTs as high as possible to reduce varnish/carbon formation. A slight downside - extended idling with the exhaust brake engaged results in combustion gas being forced back into the intake during valve overlap. This requires more frequent cleaning of the IAT (inlet air temperature) sensor located on the rear of the driver's side of the engine.



Rusty

 

[ProspectorTim]

I have heard that "prolonged idleing" is anything over 30 minutes for these trucks.



Fast idle and/or engaging the exhaust brake will save your motor.



Now for the REST OF THE STORY -

The stock automatic transmission does NOT pump fluid when in Park. Prolonged idle in Park can damage the transmission.



An aftermarket valve body is the cure for this - i. e. High Performance ATS Valve Bodies says

Transmission oiling in "Park" (good for owners with trucks that sit idling for extended periods of time)

NO doubt, other brands also have this feature, but I haven't researched them.

 

[RT66DOC]

Call 1-800-diesels (Cummins Tech line) and ask this question. I don't know about 24v motors but 4 years ago they told me 10 minutes max for my '96.

 

[MSnow]

Hey thanks guys. You really gave me alot of insight. I'm not so worried anymore. The longest I let my truck run is 10 min. So I don't think I'll have too many problems.

 

[SMolteberg]

I have been following this idling discussion, and this is my experience. I drive a Volvo 220E wheel loader for a living, and we never stops it during the winter. It can idle for up to several hours. Volvo service demand 1000+ rpm for prolonged idle. This is when the turbo start to boost, and will make the engine not to supercool and not fill the turbo with engine oil and not drop unburned diesel into the oilpan. Engaging a exhaustbrake will do the same trick. When the turbo isn't charging the seals inside it will let the engineoil seep into the turbinehouse.

The engine is Volvos own 12 liter 24V with Common rail with electronic injectors and surveilancesystem. Same tecnology as the 3rd generation Rams I belive. So if you have a boostgauge you can see when it starts to charge



Stig, Norway

 

[2broke2smoke]

i sold my first gen with 275k ... friend with a surveying business sold his two company (read beat on) first gens with 300+k



i would idle mine for an hour or two HUNDREDs of time



his crews would have them running all day ... 12hours at a time ... 6 days a week then he never plugged them in ... 0 degrees no problem fire her up at 6 in the morning ... get coffee and equip, go out survey all day drive home, shut down ... do it all again tommorow



he and i just chuckle when we hear don't idle



his current second gen has 200+k and gets the same treatment

 

[robbiesworld]

OMG what should I do now my 12 valve has 231K miles and I let it idle I guess I am just lucky! :--)

 

[PCarbonaro]

Well, this discussion does make me feel good that there is a safety margin built in to the motor.



Take home message: extended idling is bad, but if it does happen now and again, there is probably no reason to get too excited that damage was done.

 

[2broke2smoke]

has anyone on this 20k member site lost an engine due to extended idling?



i've never heard of one yet ...