ENGINE GETS RED HOT

[E/S]

Removing a t-stat causing overheating is not nonsense. What happens is a t-stat restricts water flow, in the block this allows for faster warmup's and the stat opens and closes slightly to regulate water flow as needed to maintain set temprature.
When a stat is removed, the flow restriction is removed also, Thus coolant can flow through the radiator too fast, without enough time to cool down adaquatly.
One has to remember, the restricted water flow i mentoned above, works two ways, it holds water in the block longer, as well as restricting flow out of the radiator so theres enough time for it to cool properlyl.

X 2
Plus it also helps force out steam pockets in the top of the block / head.

E/S

 

[Chief_Richard]

Thanx for all the replies to my post...keep 'em comin' boys...I love it...

 

[Egon]

Thus coolant can flow through the radiator too fast, without enough time to cool down adequately

As the water makes more passes will the smaller incremental reductions in temperature equal a large one from a slow pass?

Do the faster passes with less temperature differential mean the engine temperature is more consistent?

 

[Jim in ICT]

Like E/S, I wonder if there's an air bubble in the cylinder head or block that hasn't worked itself out. Running the engine with the radiator cap off for several minutes may help bleed the system of air. Make sure you've installed the proper t-stat & keep a garden hose handy to spray through the radiator fins to keep the coolant temps down. This is assuming that you'r not losing water via a bad head gasket or crack in the block or cylinder head. Does the oil show signs of any water and visa versa?

 

[CharlieS]

As the water makes more passes will the smaller incremental reductions in temperature equal a large one from a slow pass??

No, remember you have a constant heat source with the engine running, so with a smaller amount of temp difference between cooled water from the radiatior, there would be less temp adjustment in the block.

Do the faster passes with less temperature differential mean the engine temperature is more consistent?

probably not, thats the function of a thermostat thats working properly.

 

[irwin]

Chief_Richard;2012318] One item; I took out the thermostat a few years back. It was summer time and I was plowing a garden and she got red lined...somebody told me (can't remember who) to take out the thermostat, didn't need it. Feedback?

I assume after you took it out the tractor ran cooler for those following years?

Why did you have the engine overhauled?

Someone mentioned air pockets.. very possible, but until you're able to look at it yourself this will remain a mystery.. Bleeding the air from the engine is very important, but so is putting the engine back together properly.

Are you sure the rebuilder didn't put a new t/stat in? Many questions without being there.

 

[Egon]

No, remember you have a constant heat source with the engine running, so with a smaller amount of temp difference between cooled water from the radiator, there would be less temp adjustment in the block.

Yes but the coolant is flowing faster so does that not make a difference?

probably not, thats the function of a thermostat thats working properly.

But I thought the thermostat was removed?

 

[CharlieS]

Yes but the coolant is flowing faster so does that not make a difference?

Exactly my point, with the coolant moving faster through the system, it does not have enough time to cool sufficiently without a t-stat. nor does the faster moving coolant have as much time to absorb the heat from the engine block.

But I thought the thermostat was removed?

If you'll re-read my post, the point i was making is its the thermostats function to open and close at the temp rating to maintain proper engine temprature as opposed to trying to regulate the temp strictly by flow alone.


While some engines are more sensitive than others to this scenerio, and actual working conditions will have some effect, as will the size of the cooling system, ie: larger liquid capacity vs smaller capacity.

Its actually simple to test.
Pull the stat from an engines cooling system, start the engine and let it idle. It will take much longer to warm up. Then operate the engine under a HEAVY load, when it does heat up/overheat it either will not cool down like it should or take much longer to cool down, even when returning to a no load condition.

Or just talk to your local radiator shop and ask the consequences, they can confirm how a cooling system works.

 

[FredH]

Not mentioned yet , But what mixture anti freeze to water is being used ?

No more than 50 / 50 is recommended for most engines . One can run less than 50% anti freeze but more than 50% defeats the purpose . Seen Many a people overheated on the road and they could not understand why since they had more than a 50% content of anti freeze ( some having 100% ) .:confused2:

Anti Freeze raises the boiling point of water and lowers the freezing point , but has minimal effect on transfer of heat from the block to the radiator . That is were the water comes in since it is a better carrier of the transfer of heat from the block to the radiator .

Running without a thermostat is not wise as previously mentioned . Any "Good " radiator shop or person will tell you that , But , don't take for granted that just because you put a new thermostat in that it is working correctly or at all . Seen a $42,000+ boat that on its maiden voyage made it a 2.5 miles down river before it over heated . Reason , New Thermostat was stuck closed .

Fred H.

 

[Egon]

Exactly my point, with the coolant moving faster through the system, it does not have enough time to cool sufficiently without a t-stat. nor does the faster moving coolant have as much time to absorb the heat from the engine block.

But, but, more coolant is moving around. Each pass picks up less but there are more passes???

This may be irrelevant but on my truck installing a thermostat with too large an orifice will ensure that the temperature gauge never leaves the cold pin and if it's cold out I'm even colder and trying to see through a frosted up windshield.

Empirical observations!