what is Chryslers thought process on having the intake grid heaters cycle on and off for so long or at all, after the truck is completley warmed up? yesterday i was out doing alot of starting and stopping and noticed that even when the truck was fully warmed up, ie 95'C, that the heaters would cycle after every start
for the roughly two minutes that the manual says. i know that it is based on under hood temps[outside temp was around 3-5 degrees c] but surely if that big motor is at 95 degrees C, the under hood temps should be warm as well. and iam only talking about stops of 10 min or less. Why if this is the case dont they have the heaters on all the time? seems like the ram air as you drive would cause the temps under the hood[not engine] to drop
so my qustion again is, whats the point whem your truck is fully warmed up, manual also says they kick off at 18mph.

 

Probably the best answer is... It works.

Better to have warm air for combustion than there to be a question.

 

I believe thaqt function is driven by the IAT sensor (Intake Ambient Temperature), which is located by the air filter box. Since that doesn't stay warm like the engine block, the heater grids will cycle when the under hood temperature falls off and you are not moving.

 

Yup, the heaters are based off the intake air temp. They cycle for two minutes or until your speed exceeds about 25MPH.

 

My guess is for emissions, but it's a WAG.

 

Once your engine is warmed up, don't worry about it. Just drive away and at 18MPH, they're off.

 

Wadem, my 03 does the same thing and we're almost neighbours so we see the same outside temps. Perfectly normal....no worries here.

 

I read somewhere that a diesel at idle will actually cool down the cylinder heads enough (at idle) to begin a condition where the fuel is not being burned thoughly. Soot will start to form and emmision numbers go through the roof at idle so my guess is the heater cycle on and of when the airtemps are low to help with this problem.

Having said all that .....just drive it.

 

Grid heater works on at least 2 inputs, air intake and low coolant temp. I believe it is also receiving an input from ambient but have not proven it yet.

 

God I LOVE THE HEATER GRID!!! No more friggin "Glow Plugs"...