tndiesel

Anyone run pure 100% distilled water in their cooling system in the hot Summer months? Would it be okay to do this for about 4 months only then go back to 50/50 for the colder months?

spoolinup

I would probably worry about corrosion with no coolant mixed with the H2O. Someone here will have a more detailed answer.

C Schomer

You need additives. The nitrite and molybdate scavenge oxygen and passivate the system - put a protective chemical coating on the metal surfaces. The additives also boost the Ph, keeping it non-corrosive and helps keep the hoses from rotting. I run reduced glycol and use more DCA additive. Cummins can't give me a definate answer on if that's the right thing to do but they say.. yeh, it makes sense, it should work as long as I have the additives. Craig

tndiesel

I guess I could just run 70/30 water to antifreeze for the Summer?

OOPS

My question is why?

madhat

Hey, man...
The boiling point of water is 210*F, or 100*C.
You need the antifreeze to make the boiling temp of the water higher, along with all of the other additives that keep the cooling system from rusting out.

I'll try to find you some more info, but the world is at your fingertips with google...

tndiesel

It's actually 212 degrees at standard pressure but who's counting...

pronstar

Pure water can absorb more heat...
Race cars/bikes often run distiller water, but they add something like Redline's Water Wetter with it.

But race engines are rebuilt often. You need additives in an iron engine.

Water in a pressurized system boils at a higher temp that 212 so that shouldnt be an issue, as these trucks don't typically run over 220 degrees (at least I don't think they do).

C Schomer

Increasing thermal efficiency and raising the boiler point are two different issues. The radiator cap also raises the boiling point. If the radiator is rejecting more heat you won't have to worry about the boiling point so much. Craig

madhat

DOH!

anoldbiker

I was told by a chemist a while back that using distilled water in the cooling system is not recommended. The distilled water will draw minerals from the block as time passes. It's best to use filtered water, which has minerals in it already and not draw it from the block.

Lary Ellis (Top)

I will ask the same question asked earlier? WHY?

Unless you just happen to like corroded up parts and tons of rust in the water jacket, I can't think of a single sound reason to do it.

If you are talking about a trailer queen that only makes occasional passes up the strip then maybe you have a reason....beyond that I am not seeing what you are trying to accomplish

poor boy

I think if you look on the container it says antifreeze/coolant. It tells you on there it is for boil over protection.

papaduck

No one has mentioned that the HOAT coolant also prevents cavatation. Cavatation happens in a diesel engine. During the fireing stroke the cylinder walls will expand and then will contract so fast the the coolant will actually boil (not from heat) causing small bubbles. These bubbles then collaps pitting the cylinder walls. Over time this will destroy the engine.

If you do not plan to keep this truck for some time then forget all the above suggestions and pass the truck on to some unfortunate buyer.