I know this is old news for the regulars around here, but I just received a reply from Cummins on an email I sent regarding engine warmup and thought I'd share with all of you.

I specifically asked what warmup procedure they would recommend in cool and cold weather. Coming from a long line of gas engines, I routinely warmed up my cars for 5-15 minutes each morning in cooler weather and just didn't feel right about starting up the Cummins and heading out 2 minutes later on a cold engine. However, looks like my fears were all for not...direct from Cummins:

Summary: 2004 Dodge Idling

Solution:
Thanks for your Email message.

Heavy Duty truckers are pulling 80,000 pounds, so they need the engine to be up to minimum water temperature before putting the engine to work. However, with a Dodge pickup or RV, warm up time is not quite as critical. A 3 to 5 minute warm-up of idling after startup, for oil pressure to stabilize, is adequate in normal ambient temperatures. As ambient temperatures decrease, warm-up time should be increased accordingly and in warm climates the time can be reduced to the minimum time.

Cummins designed an intake manifold 'grid heater', which was incorporated into the Dodge Turbo Diesel applications, to aid in starting the engine in cool or cold ambient temperatures. In the Dodge, the controller is part of the truck wiring and is supplied by Dodge and the grid heater in the intake manifold is supplied by Cummins. The grid heater heats the air in the intake manifold, prior to engine start, then cycles on and off until the coolant temperature reaches about 140 degrees.

When the grid is activated during start up in cool or cold ambient temperature conditions, the heater will cycle off and on until the engine starts to warm up. The unit draws considerable amperage from the battery system and will cause the ammeter to fluctuate during warm up. In very cold conditions, the grid heater may require more amperage than the alternator produces.

Operating the truck after initial warm-up will help the engine coolant temperature reach operating temperature sooner than it will at idle speed.

We have discussed this issue with our Service Engineering group and received this response:

"We have looked extensively for data about how long it takes the engine to warm up in a Dodge truck, and unfortunately, we don't have any for the particular conditions (assuming that the engine is just idling, not running under load). Our information shows that a cold engine will warm up to operating temperature in roughly 1.5 hrs, when idled after starting at -20F after cold-soaking (ie: all fluids were that cold as well). Looking at the graph of coolant temperature vs. time, it appears that it took it roughly 1.1 to 1.2 hours to get to operating temperature from +40F."

We thank you for your interest in Cummins products. Please let us know if you need assistance in locating the nearest Cummins-authorized Dealer or Distributor Service Provider. For assistance in locating a Service Provider, feel free to use Cummins North America Dealer Locator, which can be found on Cummins website:
http://www.cummins.com/service_locator/index.cfm

Please let us know if you have other questions and if away from your computer or have a time-critical request that needs more urgent attention, feel free to call us toll-free (from North America) at 1-800-DIESELS (343-7357).

Email direct: powermaster@cummins.com

Regards,
--
Powermaster
Customer Assistance Center
Cummins, Inc.
Columbus, Indiana, USA

 

In other words, get the oil flowing and then drive it easy untill the temp reaches 140 degrees.

 

Exactly . Interesting stuff though...at idle the engine takes 1.5 hours to reach operating temp - I would have never guessed that.

 

Thats why aftermarket companies make high idle switches.....running at idle doesnt create ANY heat and is more harmful than good.

 

i guess that high idle tsb will be a good thing to get before next winter rolls around!!
later, dustin

 

Sorry for the laziness, as I know this has been posted and discussed a million times, but can one of you give me a quick synopsis of the high-idle TSB? Does it apply to my truck (2004 555 6 sp.)?

Thanks guys...

 

All 3rd generation trucks have the high idle activated from the factory. It has to be below a certain temp (I balive 32 or 30 deg F, but dont quote me on this). I balive at around 10 deg or so it will also shut off 3 cylinders to aid it in warming. I forget the exact temps but that is what sticks out in my head. I have never heard the 3 cylinder thing as it has not gotten that cold sence I bought the truck. I did hear it ramp up the speed one time though. It was when I started it to test drive it and it had been sitting all day and not started. There are several conditions that have to be met for either mode of high idle to kick in. The coolant has to be belowe a certain temp and so does the ambient air temp. The TSB as far as I know is only for 24 valve 2nd generation trucks. Im sure some one else can fill you in with more detail but that is the just of it.

 

Good post!

I generally idle the engine in the winter just long enough to get the window scraped and the block heater unhooked, and wondered if that was too long or not long enough. Sounds like it's just about right.

I think mine has done the the three cylinder thing (how do you tell?), and I've also heard it kick the idle speed up after about 3 minutes when its really cold.

Having the Jake makes a big difference, as it will start showing heat on the gauge in just a few minutes...

Anyhow, thanks for sharing the Cummins reply!

 

It will sound a little funy runing on three cylinders at high idle.

 

the tsb i was referring to was the one where they flash your computer, and you can raise the idle with the cruise control.
later, dustin

 

Oh ya, I forgot abought that one. It only aplies to auto trucks for some reson. I thought that would be nice to have as well but my service guy and several on here have said it only works on auto tranie trucks.

 

Wish i could get it to run on 3 cylinders while cruising down the road unloaded... can you imagine the kind of fuel economy increase.

 

I have not heard about this?

What is the TSB number?

Raise idle with the cruise?

Let me know
Thanks

 

Check here: http://dodgeram.info/tsb/2001/18-019-01.htm

Also I don't think it will work with a manual transmission.

Also note that it won't activate with the block heater plugged in.

 

18-019-01 isn't the correct TSB that Hairy was looking for; this particular TSB is about extended idling during cold weather operations but has nothing to do about cruise control.

The TSB that pertains to using the cruise control buttons to idle the engine up while the vehicle is stationary (and in any season or temperature) is 18-004-04, dated 03FEB04. Try a search on this site, Jack posted it somewhere around here. And yes, for "safety" reasons (I think), it only applies to auto tranny trucks.

**********
For the original poster's question, No matter what time of year, I start the engine and let the oil pressure build up to normal (takes a moment or so), then drive off easily (try and keep it under 1800-2000 rpm). I'll continue to drive it easily until the temperature guage needle rises off its stop, once it rises off the stop - I'm free to pull the trigger.