What will make a car run cool?

[Studebaker]

Other than a bat tstat?

History

90 fi 5spd

Just put in a used short block with 135k miles with some blow by. All other stuff came off of orignal engine. Which ran at a normal temp. before replacing short block.

Rebuild head.

Have set timing by feel and gas milage. Best gas milage is 41, normal is 38. Maybe running rich?

Cooling fan has never come on. Temp guage needle sits on hash mark of normal range. Heater is only ok, not hot.

Can't tell if engine power is good or low. Car does not have any reserve power in fifth gear at 60/65 mph. Don't know if this is normal or not.

Idles at 2000 rpm give or take at first start up on cool mornings till starts to warm up. Is this normal?

Changed from auto to 5 spd trans at same time.

Has Aspire brakes with 155r13/80 tires.

Tstat is a couple years old bought from Mazda.

Any ideals on what might be making it run cool?

Thanks David

[wybnrml]

Only thing I can think of for overcooling is a bad T-stat.

[Tim]

Are you still using the dual core radiator?

Could be that cold weather plus a larger radiator (with no warm ATF flowing in it) is causing the engine to run cool.

Put some cardboard in front of it, that should help. I imagine it will run at normal temp in the summer.

[grey]

pressure leak somewhere...like bad radiator cap seal.

[doylerl]

Put your location in your profile and someone close may be able to stop by and help. Go to User CP, click on edit your details on the left and scroll down to the bottom.

FWIW, I would agree with the dual core radiator post and the tstat post. I don't know much about the rad. cap leaking.

[grey]

. I don't know much about the rad. cap leaking.

how do you cook your beans?
serious bean coolers will tell you that a pressure cooker is the only way to go.
Why?
water can only reach a temperture of 212F UNLESS it is under pressure. Then water can be brought to higher temps. That is why coolant systems are pressurized - to raise the temps well above 212F.
I dont know exactly the tempertures of the hottest water in diffweent parts of the engine. I can say that it should exceed 212F, though.

With out pressure in the coolant system the water will only reach 212F and boil. Not 213F or 214Fand boil, but only 212F.

Now, steam can reach much higher temps than 212F. But that is beside the point. You dont want a bunch of steam in your engine anyway.



Anyway, that is why beans are cooked in pressure cooker...That's also part of Colonel Sanders secret recipe

[grey]

well, that (which i dont really understand that well) and the fact that I have seen happen before.

[resuwrecked]

^cooling systems are not pressurized to raise temps, i don't know why you want your engine running over 212. the reason you need a good cap that holds its pressure is to keep the coolant from boiling over, not obtain a higher temp. every psi on water raises the boiling point 3 degrees. We are cooling engines here, not cooking beans lol.

[grey]

^ keep the coolant from boiling over, not obtain a higher temp. every psi on water raises the boiling point 3 degrees. lol .

you said it yourself.... Now where is that heat coming from?
The laws of thermodynamics tell us that heat travels down hill, so to speak. That the engine temperture must be greater than than coolant temperture for the heat to transfer from the engine to the coolant. And likewise, the coolant temperture must be greater than the air temperture to transfer out of the coolant.

The key here is the fact that there are some parts of the engine that may exceed 213F (for instance). As a quantity of water passes near the hot spot heat is carried away within in that quantity of water and then mixes with the rest of the coolant system. Now if the entire coolant system is not pressurized, then that quantity of water passing the hot spot will not reach above 212F. If the system is pressurized then the water passing that hotspot will reach a higher temperture before mixing with the rest of the coolant .... causing a higher coolant temperature ...and eventually pass on more Btu's out the radiator

Does that make sense? I think the original poster was asking why water tempertures seemed low.

I wonder how he measured it.

[grey]

^ We are cooling engines here, not cooking beans lol.

speak for yourself

[JohnGunn]

Here is a list of temperature controlled events from the 1990 Ford Service Manual.

Temp in F __ Event

Temp rising
140 ________ Set idle speed should be attained.
182-188 ___ Thermostat sub valve begins to open.
188-193 ___ Thermostat main valve begins to open.
207 ________ Fan comes on.
212 ________ Thermostat - both valves fully open.

Temp falling
194 ________ Fan off.
181 ________ Thermostat main valve closed.
176 ________ Thermostat sub valve closed.

The fact that the fan does not come on indicates that your temperature is not reaching 207F, a temperature which could be achieved even without any pressure in the system.

Unless it is very cold and windy where you are, I don't see anyway the engine at idle would not generate enough heat to open the thermostat. It may be stuck open. You could test this by putting your hand on the upper radiator hose as the engine warms up. It should take several minutes before the thermostat starts to open and it suddenly starts to warm much more quickly. If the warming is gradual from the start without any sudden change it might be always open.

John Gunn
Coronado, CA

[ShagFestiva]

speak for yourself

lol

[resuwrecked]

you said it yourself.... Now where is that heat coming from?
The laws of thermodynamics tell us that heat travels down hill, so to speak. That the engine temperture must be greater than than coolant temperture for the heat to transfer from the engine to the coolant. And likewise, the coolant temperture must be greater than the air temperture to transfer out of the coolant.

The key here is the fact that there are some parts of the engine that may exceed 213F (for instance). As a quantity of water passes near the hot spot heat is carried away within in that quantity of water and then mixes with the rest of the coolant system. Now if the entire coolant system is not pressurized, then that quantity of water passing the hot spot will not reach above 212F. If the system is pressurized then the water passing that hotspot will reach a higher temperture before mixing with the rest of the coolant .... causing a higher coolant temperature ...and eventually pass on more Btu's out the radiator

Does that make sense? I think the original poster was asking why water tempertures seemed low.

I wonder how he measured it.

We understand the correlation between pressure and boiling temp. The op was asking about a lack of heat issue, so I'd imagine his coolant temps are a little south of 212 anyway, so cooling sys pressure most likely is not his problem. He measured his low coolant temps most likely by the dash gauge and by hand from the lack of heat from the vents. He should be able to get up to operating temp and have heat with the rad cap off, and no pressure.


But to get back on topic and off a grey explanation of thermodynamics and how they affect the well being, pleasure and comfort of our little cars... either hung open t-stat (replace with a correct temp/brand) or an air pocket. Do you have any small coolant leaks by the way? I had to use this (snapon's version)

http://www.johnsonmfg.com/temp/J360CS.htm

It was the only way i could get heat in my last stiva, something about it trapped an air pocket.

speak for yourself

Add you location to your profile, I cooked you some beans in my pressure cooker and need to know where to take them.

[grey]

Add you location to your profile, I cooked you some beans in my pressure cooker and need to know where to take them.

take them wherver you like


as for the rest, if you dont understand why pressure relates to coolant temperture then do your own research about it. when you have something factual and helpful to say... then give that a try


-------------

Suffice to say that when an engines cooling system is designed pressure is part of the equation.

The helpful quote from FSM provided earlier was only about coolant tempertures measured at some places (thermostat), or some averaging temperture. It did not specify. There are points in the cooing circuit where tempertues are much greater. Tempertures higher than 212F.

[Studebaker]

Thanks everybody. Esp. on how to check the tstat.

David