cooling issues

[Lumpy Grits]

Is this how you have the t'stat positioned?

https://www.howacarworks.com/cooling-systems/how-to-replace-a-car-thermostat

LG

 

[jakeh937]

That went through my head as well i spent 30 minutes watching it run and following belts figuring out what turned and in what direction it turned to make sure that i had everything on properly and that it wasnt something simple like having the wrong belt configuration or belt on the wrong way. i will grab a few detailed pics of the engine bay here in a few and get them posted for you guys maybe you will catch something that i am missing

I see what ur saying with the belts. And your sure the pump isn't a reverse flow or anything weird?


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[Lumpy Grits]

I see what ur saying with the belts. And your sure the pump isn't a reverse flow or anything weird?


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OP is run'n a 5.0, out of an '87 'Tang.
LG

 

[Manic Mechanic]

here are some pics of the front of the engine and belt set up

 

[mriplaybass]

Looks like you definitely have a reverse rotation setup for the pump. As others have already said, the engine won't cool if the pump is turning in the wrong direction. The reason it does cool without the thermostat in is that the pump would be pulling coolant from the top of the radiator and since there is no thermostat in the way of the reverse flow, it does cool, although you are still pulling the hottest coolant from the top of the radiator. I know it's a pain in the *** to have to pull the pump to check it out, but a damaged engine is not worth taking chances. You might get lucky and be able to see a part number on the pump. If you do, you could look up the part number and check which direction that pump is intended to turn.

 

[Manic Mechanic]

Looks like you definitely have a reverse rotation setup for the pump. As others have already said, the engine won't cool if the pump is turning in the wrong direction. The reason it does cool without the thermostat in is that the pump would be pulling coolant from the top of the radiator and since there is no thermostat in the way of the reverse flow, it does cool, although you are still pulling the hottest coolant from the top of the radiator. I know it's a pain in the *** to have to pull the pump to check it out, but a damaged engine is not worth taking chances. You might get lucky and be able to see a part number on the pump. If you do, you could look up the part number and check which direction that pump is intended to turn.

last time i had the pump off i did check it and the pump is flowing in the correct direction. but i will check it again next time i go to start it and look at the belts more closely to see what direction they spin

 

[mriplaybass]

If you don't have a thermostat in, it should be obvious even with the engine cold. I believe that if you are facing the engine from the front, your upper radiator hose connection is on the left and the lower hose is on the right. If it is the correct pump and it is turning in the correct direction, you would be able to see the coolant flowing from left to right through the radiator cap. Of course, don't open the radiator cap if the engine is hot. Start with a cool engine with the cap off, but don't walk away! As the coolant heats up, it may decide to belch out a whole bunch of coolant!

 

[jakeh937]

Looks like you definitely have a reverse rotation setup for the pump. As others have already said, the engine won't cool if the pump is turning in the wrong direction. The reason it does cool without the thermostat in is that the pump would be pulling coolant from the top of the radiator and since there is no thermostat in the way of the reverse flow, it does cool, although you are still pulling the hottest coolant from the top of the radiator. I know it's a pain in the *** to have to pull the pump to check it out, but a damaged engine is not worth taking chances. You might get lucky and be able to see a part number on the pump. If you do, you could look up the part number and check which direction that pump is intended to turn.

Exactly my thoughts just worded wayyyy better hahaha. It has to be something with a flow. And the fact OP said it's fine with no t-stat and overheats with one in.. that's the only thing that I can think of. It's eccenually like blocking the radiator off


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[Manic Mechanic]

so i spent some more time working on the jeep this weekend (along with other jeeps) according to mustang forums the set up is correct for this motor and the belts are routed correctly. the pump also matches the one that was taken off during the restoration. im wondering if the pump is simply not generating enough pressure to circulate the coolant with the thermostat in.

 

[jakeh937]

so i spent some more time working on the jeep this weekend (along with other jeeps) according to mustang forums the set up is correct for this motor and the belts are routed correctly. the pump also matches the one that was taken off during the restoration. im wondering if the pump is simply not generating enough pressure to circulate the coolant with the thermostat in.

Man that is just bizarre! Especially if it's belt driven and the belt is tight there's nothing else to a water pump.. [emoji848] I don't think there's any other way to generate more flow from a belt driven pump??


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[gert]

Hope he doesn't have a clog in a coolant passage


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[jakeh937]

Hope he doesn't have a clog in a coolant passage


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I thought of that too. But if there was a clog somewhere, then it still wouldn't cool with the t-stat out right?


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[gert]

I thought of that too. But if there was a clog somewhere, then it still wouldn't cool with the t-stat out right?


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Lol yes normally so, but it shouldn't over heat with a t stat either


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[Manic Mechanic]

im glad im not the only one scratching my head over this. in all my years working on cars ive never had an issues like this. worse yet this is the same set up that has been run since the early 90's with little to no problem

 

[Manic Mechanic]

update........

ok so i was concerned about it being something stupid and im pretty sure it was as soon as the new part comes in i will know for sure.

from what i was able to figure out (using an engine scope cam while running) the coolant is flowing when hot. the problem i believe is the temp sensor for the electronic temp gauge. i have been shutting the jeep down as it approached 250 (way to hot). from what i can tell its reading way off and around the 235-240 mark it is opening and circulating just fine with no pings or excessive heat on the manifolds (intake/exhaust) and it hovered at that temp for over an hour with the fan on like it was so-pose to. further more i noticed it leaned it self out as it would run rich which is typical for a cold motor as it warms to operating temp.

all in all we have been racking our brains trying to figure this out and in reality there was nothing wrong with the way it was running it was simply a gauge reading incorrectly. hopefully i will have a final conclusion for you as soon as the new parts arrive.

 

[Lumpy Grits]

I strongly suggest a mechanical temp gauge and a dedicated dash lead to the battery NEG(-)terminal.
What gauge and sender are you using now.
Here's a good unit-
2-5/8" Water Temperature Gauge. Black Dial, Mechanical Water Temperature Gauge.

LG

 

[Turbogus]

A BIG X on mechanical gauges!

Another thing that occurs is I remember stainless steel braided hoses back in the '70's that were only a covering for substandard radiator hose. Without an internal spring if the hose seperates from the braid it can still collapse causing a restriction.
On Black Betty, I have a Flowkooler pump on mine and I found I had to make an internal spring for the upper radiator hose as well.