Timmer

the duramax's are crying about over heating and were lucky to get heat

HOV

I get heat at about the same point in my commute as my Camry does. This is what I do:

- Plug in the truck on a timer to start 4 hours before I wake up
- Start in neutral to get fluid to the TC
- Set the exhaust brake
- Set the high idle
- Wait for the EGT's to get up to the 450 range

When I take off, I take it easy for about 3 miles. Then I hit one turn and give it some throttle. That makes the heat come on like a switch.

XLR8R

Winter Front Delete/Thermostat Bypass

03RAMBUNCTIOUS

mine takes the same time as all of yours to warm up, plugging it in REALLY gets the heat faster.

a couple questions

when its 30 to 60 degrees out i can let my truck get to operating temp then, and pull up to a stop light and tap the pedal and the rpms will stay at 900-1000, but it will not do this when the motor is cold or when it is warmer outside.

when its 10 to 20 degree out the truck will idle up to 1100rpms on its own, can i manually make that happen on the 30to 60 degree days?



can i high idle flash my 03 manual tranny truck?

recently on these cold morning the truck will start sputter then die, sometimes 2 or 3 times. until i can get it to run for a solid twenty seconds then is wikll be fine


Thanks max

jamesbfishin

So heres an observation that I made with my truck. I have the same type of commute, appx 12 miles, 20-25 mins with a mix of speeds 45 mph being the top. On 2 seperate occasions with temps being around the low 20's I drove to work with the O/D off, thinking that running a higher rpm the Cummins would warm up faster. In actuality, it ran cooler, both times. Normally when I get to work the temp gauge reads around 175 or so, without O/D, the most I got was like 160. Only thing I can think of is that the higher rpm was pumping more coolant through the system, taking the temps down lower. This was with no winter front and blockheater plugged in all night.

XLR8R

Mostly, it's because more airflow at higher RPM, with equal load - makes for lower EGTs.

Sometimes, when I need to warm up the truck faster, I drop it into the next higher gear and mash the skinny pedal while keeping under 2K rpm... plenty of smoke & toasty EGTs, and I get cabin heat pretty quick.

03RAMBUNCTIOUS

XLR8R, Your fix to the cold mornings sounds very costly at the ole fuel station.

jamesbfishin

XLR8R

Maybe I read your post wrong, but dropping a gear and giving it more juice sounds very much like the scenario I did, but with completely opposite results. Maybe it's a difference between an auto and manual tranny, but what would be the difference between switching off O/D and running rpms around 1700 instead of 1200, you're still increasing rpm's?

XLR8R

Just semantics James - lower rpm with equal load = less cooling of EGT due to airflow which heat soaks the engine faster as well as uses more fuel (heat energy).

rallydriver

I was wondering about that. I would think that it would be the same as the guys who drive around after a cold start in the morning w/ an exhaust brake on. Both exhaust brake, and upshifting and allowing the EGTs to climb with lower rpms and a higher throttle achieve the same goal: to put more load on the engine to warm it up faster.

The only question I have for either of these warm up proceedures is if the extra fuel due to the extra engine load is doing more harm by washing down the cylinder walls with the excess fuel. I certainly would wait at least 8-10 minutes after cold start to start loading the engine that way.

-Chris

billie

Am I missing something? The heater core gets its heat from the block, not the rad so large capacity cooling system shouldn't have any effect on cab heat. The t-stat only opens on heat to exchange to the rad.

Heated garage here...no issues

Cya

Lightman

I"m not sure what everyone is so worried about either. I do much like rallydriver does as far as taking it easy with the rpms while the temps come up - but as far as cab heat goes, after leaving the truck plugged in all night, I get heat within the first few miles of driving. Not sure why everyone is so concerned with 'operating temp'..just cuz the coolant temp is up to 190 or whatever on your gauge doesn't mean you've done your truck the favor of a true full temp long drive where the OIL temp gets hot enough to boil off moisture/contaminants etc.

XLR8R

The cab heat issue is the result of 1100# of CTD that acts as a heat sink.