Warming up the Cummins?...

[Dixie Dawg]

As you can see in my sig, just got my truck, first diesel I've owned. With it getting colder here in the NGA mountains, how long should I let it idle at warm up? Granted, it doesn't get that cold here. What I'm worried about is letting it idle to long and not burning off all fuel since I don't have an idle controller. Also, I only work about 2 miles from home, so the engine doesn't get that warm anyway. Anyway, sorry for the long post, just wanting to be good to the mighty CUMMINS!

 

[Todd T]

you shouldnt let it idle for more than five minutes or so. also with only driving that far to work you should get into the habit of changing your oil more often than recomended. it will not clean out with that little of drive time on it.



the engine doesnt really build heat until it is under a slight load. if you can run the RPM's higher (2000) and not lug it to work.

 

[Todd T]

another thought

you should consider some trips or pull a small load around, to get it broke in. that kind of driving you discribed, will be hard to get the engine broke in, and will take longer. you should also go 20 to 25 thousand miles before switching to any kind of synthetic oil.

 

[Midnite]

I'm already using my block heater even though it hasn't dipped below 40 deg. F yet. (actually I also have magnetic pad heaters stuck to the bottom of the engine and transmission oil pans too).



At the very least I notice that it cuts down on the 3rd gear to 4th gear hunting that normally happens when it's cold.



I think it's also time to put on the winter front...



Mike

 

[B.G. Smith]

Dixie Dawg, if your trip to work is not on the freeway, I would just start up and go if you can keep the speed under 35-40 mph, the oil pressure is awfully high when the engine is cold. Of course you could plug in the engine heater and it will already be warm in the morning. As stated above, it will not warm up if it is left to idle, I put mine in drive and run the rpm up slightly above 1000 rpm, seems to warm up faster. bg

 

[Bigsaint]

Dixie D, I recommend plugging in for an hour or two before you leave for work, set it up on a timer. You won't hurt anything except your electric bill and the Cummins will be happier.



I also work too damn close to home (never thought I'd say that, lol) and my short trip to work is about 8 miles. If time permits, I go the 'long way', about 15 miles. May sound stupid but the Cummins is warm and I get a few more happy miles under my belt.



Scott W.

 

[Vaughn MacKenzie]

When I start up in the morning the oil barely has time to start circulating before I take off! I fire it up, let it idle at normal speed for about 10 seconds, then slowly raise the RPM to about 1500 for a few seconds, then take off. I drive slow and easy for a mile or so and keep RPM under 1900. I park outside but it hasn't been cool enough yet to plug in, usually in the low 50s overnight.



I have been watching my tailpipe since it is now cool enough in the AM where the grid heater doesn't quite kick in and it makes a little blue smoke at startup. If I just sit there and idle, it will smoke at least 1-2 minutes before it clears. If I take right off, even slow and gentle, it is gone in about 10-15 seconds and the exhaust is clean from then on. I think even the smallest load is much better for it and generates more heat than just spinning away there at idle & smoldering on what fuel it is using.



Vaughn

 

[Greg Boardman-RIP]

If you had read the book in the glove box it does say to wait until you have oil pressure. I drive then but take it easy until it gets up to operating temp... ..... I haven't had a problem with the cold yet It was 104* today and about 84* now at midnight... .....

 

[Chad Sheets]

Block heater works great. No need to idle past a minute in reality. As these guys stated, no load, no heat build up. No heat build up means the combustion temps are not at their peak, and the result is white/blueish haze which is nothing more than unburnt fuel. Careful though, too much of that idleing in the cold can create enough unburnt fuel to start causing big problems with washed out oil rings on the pistons.



Another tip from me to you, throw the transmission down in "N" as soon as you get it fired up, The transmission is the weak link as you have heard. By doing this it alows the transmission fluid to circulate and build up heat. If you keep it in "P", the fluid is motionless.



One more thing, keep the truck in overdrive at all times. When you push that button to go out of OD, there is a big huge spring that must be compressed with pressure. You only have so much pressure to go around. The pressure is what makes all the bands and clutches work properly. Let it lug in OD. Your transmission will last longer, and we know the engine can handle it. Good luck.

 

[Dixie Dawg]

Thanks for all the replies guys. Thought I was doing the right thing by letting it idle for about 5 minutes this am, but I guess not. I'll probably pull out just after oil pressure, and go get breakfast before work, about 10 miles instead of 2. Nice tip on the transmission also, Chad. Thanks again!

 

[Mpoland]

Dixie,



Don't forget in the colder weather, block the air flow through the radiator. I slide a piese of cardbard in front of the radiator with a 8-10 inch hole cut in the center of it. It helps keep the beast warm wihen it's cold out... but if you do any pulling, be sure to remove the cardbard.



I drive about three miles to work so I'm right there with you. In fact, I advoided a desiel and first bought a V-10 because of the short distance to work. The gas prices shooting up a couple of years ago, caused me to switch to the desiel. Sure glad that I did!



Hey Greg... . does it ever get cold out there at "The Stumps"?

 

[Dr.Evil]

I wouldn't do the cardboard right in front of the radiator thing. WAY too easy to really overheat the engine. Just dropping in behind a delivery truck can cause a loss of airflow. If Your worried about warmup get a winterfront that snaps on. make sure SOME air can get to the radiator but the radiator fins have to be able to get air to flow over them. You get a diesel engine too warm and you have problems.

 

[Greg Boardman-RIP]

MPoland,

I've seen six inches of snow in December and Jan... ... ... ... Gets cold..... Just hot now

 

[Cooker]

As far as the cardboard in front of the radiator goes, there are many members who do this (including myself), and a few who remove their fans AND install a piece of cardboard or similar means to block the airflow.



Last winter I didn't not have a single time where the truck even came close to overheating (needle never touched the 190 mark). Granted I never towed more than 1500 lbs last winter, but the truck is so overcooled to start with (for most situations), the radiator cover is the best way to go, IMO.



I will agree one needs to be careful to leave a hole in the center to flow air over the fan clutch, and be aware of the potential problems if they are towing a heavy load.



Shoot it hasn't gotten bas 55 here in the last few days, I'm about the pull the cover out of the basement and put it back in.



JMHO,

Ryan

 

[SnoKing]

Everyone else quotes Bill at DTT as saying to lock out overdrive until you get on the freeway. So Chad Sheets you seem to have conflicting info. If you lug around in OD you have very low line pressure to the lockup in the TC, and if you give it to much power you can slip the clutches. Engine should be over about 1700 to 1800 RPM before really pushing the go peddle. I'll go with what Bill says and lock mine out around town. Besides the 24V is not a lugger!



SNOKING

 

[Cooker]

Bill told me on my 12v no less than 1500 RPM.



-Ryan

 

[KatDiesel]

I keep my overdrive locked out for anything under 60mph or so. I hate when it goes into overdrive and I have to slow down for traffic. I love it around town, not to mention when ya get a chance to "buzz" someone

 

[jmeehan]

Short trip milage?

What kind of milage are you guys seeing that only drive ten miles or so to work? I drive about the same distance and my last tank was up to 16. 5 m. p. g. from 14.

I just went over 10K, and I was getting 18 m. p. g. when I went south to buy the truck.

 

[Wayne M]

Bill Kondolay of DTT----we all know him as the guru of our transmissions told me it is always best to keep the RPMs above 1500 to 1600 as much as possible. You can do this only with OD off when in town.

 

[Chad Sheets]

You can keep the truck in D all year long if you want, just dont do it with any real power from the engine and expect to romp on it and everything last. Iam no guru on trannies at all compared to Bill, but running a R&D test stand for Allison Automatics and building them for Allisons has given me enough knowledge about trannies to figure things out.



In our tranz, pressure is required to make all the bands and clutches bite to stop slipping. If you are running in D, then most of your available pressure is holding that big spring. I have over 400 HP at the rear wheels, so this OD thing works outstanding for me since most of my time is spent well over 1500 rpm's, but if you are stock, or close to stock... nothing to worry about more or less. Just might keep your stuff from going south a little premature thats all.