High Ideal Warm up ??

[TKarnas]

Just found that the truck will increase ideal when first starting up the truck. Usually have my truck in the garage(55 deg) and the truck never did this. I had to leave it out over night and the temp was 5 deg. I was letting it warm up and the ideal increased.



My question is do I need to wait for the ideal to go back down? and how long do you all let the truck "warm up" when the conditions are cold.



Thanks

 

[CSkal]

That increased idle is normal when temps get that cold to prevent cylinder washdown. You could probably let it idle a few minutes like that while you put on your seatbelt, play with the radio, etc. After that you can just go. The idle will return to normal if you step on the brake pedal, it will not drop right down, it will decline slowly to regular idle speed.

 

[RShipp]

It will also go back up if you are parked somewhere and it is still cold out, but like CSkal said, just tap the brake and it will go back down.

 

[jelag]

We let our trucks sit out where its cold... we own 4 of them... each seems to have different software in the ECM and each will cycle the speed of the engine and the exhaust brake at different rates... .

We jump into a cold truck, start it, put the belt on, and adjust the seat, wheel etc and drive it away... . letting them run most of the day... Like mentioned above we let them sit and idle hearing the speed change and exhaust brake change as it gets cold and warm... .

 

[TKarnas]

thanks to all... . still learning about the cummins !

 

[RShipp]

It's just the 3rd Gens that do this. The CM550 ECM in the 98. 5-2002 didn't have enough room for this option.

 

[jeepit]

It's just the 3rd Gens that do this. The CM550 ECM in the 98. 5-2002 didn't have enough room for this option.

Rock on 2nd genners, Smarty takes care of this for ya and more.....

 

[RShipp]

Oh, trust me, not knocking the 2nd Gen. Great engine, starts quicker than my CR. I just went with a new one to get the 4dr. I would love to have a 12V in my 2005. I know I could do it, but there are alot of bridges to cross. Plus, mine runs fine.

 

[Wingate]

When I actually get to drive my truck, I fire it up, shift to neutral and set the PTO mode at 1200rpm. I just don't feel that low idle in cold weather circulates enough oil to the top end of the engine. My truck will automaticlly increase speed if you leave it in Park, but its my understanding that the 48RE doesn't circulate fluid in Park.

 

[TKarnas]

Will I do any damage to the motor if I do not let the motor warm up? Sometimes I just do not have the time to wait 5-10 minutes. most of the times I have the truck in the garage or its sitting in the parking lot at work

 

[HOBrian]

The time it takes to get the belt on and the wheel down I am off.

 

[RShipp]

There is no problem with not letting a cold engine warm up. Just be sure to be easy with the thottle until it hits operating temp. The reason is that the pistons are aluminum and the block is iron. Two different metals with different heat expansion properties. Aluminum heats up quicker and expands quicker than iron. At operating temp there will be a lower differential in the two metal temps under load. Me personally, I let mine warm up until the manifold heater cuts off. You can tell by watching the volt meter. When it goes to 14V then the manifold heater has quit cycling.

 

[BlitzkriegSSII]

It's just the 3rd Gens that do this. The CM550 ECM in the 98. 5-2002 didn't have enough room for this option.

The 2nd gens do have this option. Mine does the high idle and does the 3 cylinder run mode as well when the temps are low enough.

 

[RShipp]

The 2nd gens do have this option. Mine does the high idle and does the 3 cylinder run mode as well when the temps are low enough.

It did all that stock? 3 Cylinder mode? Care to explain?

 

[Wingate]

It did all that stock? 3 Cylinder mode? Care to explain?

Didn't know Cummins did that too. Some of the Cats do that, most customers complain about it, but it forces them to let the coolant temp get to atleast 130 degrees before they can slam the load to it. The 3412E cuts out one side of the engine to simulate some load, thereby increasing load on the other bank, and it actually warms the engine up better/quicker than if all 12 were firing. Didn't know that Cummins ever played with that too.

We've got an old 7. 3L PSD with the cold cutout, when that thing is cold in the morning, you can hold it on the floor across the parking lot and never get over about 10 MPH...

 

[RShipp]

Didn't know Cummins did that too. Some of the Cats do that, most customers complain about it, but it forces them to let the coolant temp get to atleast 130 degrees before they can slam the load to it. The 3412E cuts out one side of the engine to simulate some load, thereby increasing load on the other bank, and it actually warms the engine up better/quicker than if all 12 were firing. Didn't know that Cummins ever played with that too.

We've got an old 7. 3L PSD with the cold cutout, when that thing is cold in the morning, you can hold it on the floor across the parking lot and never get over about 10 MPH...

Ok, but you are talking 3rd gen right? Common Rail injection. 3 posts ago someone said that the 2nd gens had this option. 2nd gens have the VP44 injection pump. Now, how do you cancel out 3 cylinders on a mechanical injection pump? The only thing electronic on a VP pump is the thottle.



The powerstroke uses lube oil to fire the injectors. That's the reason they don't have any power until they warm up. Cold oil is more viscous and the proper amount won't make it to the injectors until it heats up. So, there won't be sufficient oil flowing to the injectors to get a full stroke to inject full fuel.

 

[BlitzkriegSSII]

Sorry about that i had been gone for a while.



Yes my 2002 (vp44) does have the 3 cylinder high idle mode. I live in alaska and it must have been a dealer option. I have never used a smarty.



When it goes in to 3 cylinder mode it starts and idles at 800 rpm for a bit, then slowly picks up speed, and then you can hear it switch over to 3 cylinder mode. Sounds like its going to fly apart. But it has to be very cold.



Im not sure how the pump does it but im guessing that it has some thing to do with the electronic metering valve.

 

[Travis_Ray]

I know this thread is a couple weeks old, but I'm going to post anyway.

The 3 cylinder mode in the 2nd gens is an option in these trucks that comes not turned on. The smarty simply enables it. The 3 cylinder idle usually kicks in at temps around 0*F, and just the same as any other high idle on these vehicles tapping the break stops it. The truck will ramp up with it's regular high idle, then kick over to 3 cylinder, and you end up needing to change your britches after that first time.

The vp44 isn't entirely mechanical. Cummins has the ability to shut off each cylinder when troubleshooting a problem, so there has to be electronics in there somewhere. I just know that it does indeed happen. The high idle/3 cylinder idle is all the same package on the 2nd gens, you can't have one without the other. We have no control over that idle either. The temp must be cold enough, the parking brake set and truck in Neutral or park. We can't control it from the cruise or enable it at will.

 

[RShipp]

Interesting. I was not aware that the VP trucks could do cylinder cutouts. Anyone know exactly how this happens? I would like to know more.