Closing off the radiator

[JHZR2]

That’s what I found when I checked the oil this am.

Oil doesn’t have any streaks of moisture, actually stays far less black than my IDI Mercedes. I think it’s just that it has a 3 gallon sump.

I don’t short trip it, but it also has a 26qt cooling system. Most of my trips are 30 miles long-ish.

So I’m thinking I just need to close off the radiator, especially when operating not with full payload. Most of that hauling is done.

But there’s AC, AT cooler, etc. How should I block it?

It starts very easily in freezing conditions, but I might start plugging it in anyway just to get more heat in there so more time at (water) temperature Is obtained...

 

[AutoMechanic]

Could you block it off with some high pressure fittings or something or maybe some bolts? Like maybe take off the hoses and do it that way each time?

 

[JohnnyG]

You could try some artfully cut cardboard, since I doubt that you'll have too much problem maintaining cooler cab temps and A/C operation.
But I'd also make sure that you thermostat is of the proper temp. and working correctly. I wouldn't block the trans cooler.

 

[Astro14]

I would use a block heater to keep condensation down, and allow more time at temp to reduce moisture in the sump.

I would also verify thermostat function, if it’s weak and opens early, or doesn’t actually open at specified temperature, you won’t be getting rid of moisture.

I wouldn’t consider blocking off a radiator unless you’re continuously operating below 0F - where you have a problem keeping enough heat in the engine.

 

[Astro14]

Block heater made a huge difference in my 240D once the temps were below freezing, particularly the glow plug cycle time for start and on cranking speed. It also got up to temp much faster. Granted, your truck is far newer, but the same principles apply - warmer oil and coolant at the beginning of the drive cycle makes for easier starting and faster warming, both helpful in driving off that moisture.

 

[JHZR2]

Block heater made a huge difference in my 240D once the temps were below freezing, particularly the glow plug cycle time for start and on cranking speed. It also got up to temp much faster. Granted, your truck is far newer, but the same principles apply - warmer oil and coolant at the beginning of the drive cycle makes for easier starting and faster warming, both helpful in driving off that moisture.

Yeah, the engine starts like a champ (as do my w123 and w126 cars), in the temps I expose them to. Granted that’s not usually below 0F.

This one just has so much excess capacity I think. I can tool around town, drive to the local HD, etc. and it gets to temp just fine. It actually oscillates less than some report their Cummins trucks with the uprated cooling do...

So I think the key is less time warming up 9 gallons of engine fluids, plus 6 gallons of ATF in this baby.

 

[Jetronic]

I would use a block heater to keep condensation down, and allow more time at temp to reduce moisture in the sump.

I would also verify thermostat function, if it’s weak and opens early, or doesn’t actually open at specified temperature, you won’t be getting rid of moisture.

I wouldn’t consider blocking off a radiator unless you’re continuously operating below 0F - where you have a problem keeping enough heat in the engine.

Agreed, no blocking off unless you can't reach normal operating temps with functional thermostat.

 

[JHZR2]

I did give the radiator block a try. Used a plastic for sale sign. It helped get the coolant hot.

(I don’t know what the dirt (like water spots) inside the cluster on the left side is. I need to try to open it and clean it)

These Dodge Cummins trucks are known for a dancing temperature needle as the thermostat opens and shuts. Mine has never done that in my observation. With part of the radiator blocked, it does that cycling.

I’ve used the block heater a few times too. Putting it on for an hour or two results in the needle moving a tick above its resting spot, but not to 140. Ive read that the heater is good for a max of about 85F rise over ambient if it is left on for four or so hours. I dont know that I’ve run it that long.

Anyway, blocking the radiator does help.

 

[BrianF]

I try to block off the rad to some degree on just about everything I drive. Its a must on my 3500. I know to open the flaps when the cooling fan comes on under light load.

I need to keep every ounce of heat I can, when its -40 I cannot keep the windshield from frosting up inside.