Overheating

[donaldray]

Broke down in Three Forks, Montana. Took thermostat out and truck could not get up hill without overheating 3 times. Made it too flying J and notice leak under water pump and currently got it off too replace. Question is this: If water pump is not problem . Can I Flush system too clean out EGR cooler and can I leave thermostat out untill I get too Dallas, Tx.? And can I run with just water with no antifreeze for that far. Don't want too throw money at it until I know for sure if it was the pump.

[donaldray]

Also, I have a EGR delete and this is a ISX 870.

[tlzimmerman]

If it were my truck, no more of a job it is to put in or take out a thermostat I would put it back in so the truck ran at the correct temp. Same goes with coolant, they are designed to run coolant, not water....I have always been told straight water doesn't pull heat away as efficiently as coolant, and it also lowers your boiling point to run straight water.

I don't suppose it would kill it to run on water, but if you can beg borrow or steal some buckets to save your coolant you should be able to reuse it just fine.

[donaldray]

Good point.

[donaldray]

That's the answer. Thanks

[snailexpress]

Don't use tap water. In Walmart you can have distilled or deionized at least.

[Rawze]

In an emergency, you do what you have to for a day or so -->

BUT...


In general --- I have seen destroyed liners form people running straight and/or distilled water on a wet liner enigne!!!!!

   

and...




It is the NITRATE ADDITIVES IN THE COOLANT that prevent this.

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ALSO::: --> Taking out the thermostat will not force coolant through the radiator. Only small amounts will flow to the radiator but the bulk will still bypass and run back down to the pump through the block due to osmosis. My understanding of it is that thermostat itself blocks off the bypass circuit, forcing coolant into the rad as it opens all the way. One can think of it as a sort of "this way -- or That way" type of circuit, depending on the temp of the coolant as it opens? At least that is what the video suggests. It also says that taking out the thermostat causes the engine to overheat.

It is explained at 2:53 in the video...

[Billdozer2]

Good video. Yeah I was going to say, you can't take out the thermostat like you can on a car engine. The Cummins cooling system is different and needs a thermostat to operate properly.

Same goes for the oil thermostat. If that is removed, the oil bypasses the oil cooler and the oil overheats.

[dhirocz]

Most car engines can't tolerate thermostat removal either. There has to be a choke plate in it's place to throttle down the speed of the coolant. if not, the coolant doesn't stay in the radiator long enough to remove the heat, and the engine overheats.

I would say you might get away with water for a short time if the cooling system holds pressure. That pressure helps increase the boiling point of the coolant, as does coolant itself. The engine will be VERY prone to overheating under load, unpressurized on water alone. This is a highly unstable cooling system configuration.

With the lower boiling point, bubbles form on the backside of the cylinders far easier and earlier, bubbles which also isolate the backside of the liners from the water, overheating them and further interfering with heat transfer. At this point what happens varies by engine design, but generally, the Pistons and rings get superheated and galled, wrist pins blue from the heat, oil breaks down, the water jackets flood with steam bubbles which collect in the head as the overheating 'runs away', pressure forcing out what water you have left and superheat the engine. Since heat moves up, it usually junks the head/head gasket. What happens is a huge pressurized steam pocket forms in the water jackets. When run under these circumstances, an engine can quickly destroy itself if it gets out of hand.

Havent seen this personally happen on an ISX, but I have seen it happen otherwise and it's never pretty. I wouldn't run mine like that for that reason. Please fix it properly.