Thermostat in my truck was broke open so took apart to replace it.I know this is going to sound crazy but noticed the replacement Motorcraft thermostat had "towards radiator with arrow"?...Now does that writing go towards the back of the head with arrow pointing forward or does the writing go towards radiator?...Next does it make a difference?
Thermostat Placement
- Thread starter rpm427
- Start date
Arrow points in the direction the coolant flows, so in this case, the arrow should be pointing towards the radiator.
So does the arrow which points up go to the front of block towards front of motor or back of block?Does flow go thru top hose down or other way?Why does the position of thermostat matter when it has three holes?I'm looking at this as you sitting in vehicle as it would be correct when you order parts?
Take a look at this diagram:
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Coolant flows up from the block, through the thermostat housing, through the upper hose, and into the radiator.
As you're looking at it, the arrow should point away from the engine block and towards the thermostat housing/upper hose nipple assembly.
gandalf
Senior Member
I think what everone is saying is, don't put the thermostat in upside down. If you do that then it very likely will not open, and you'll find things heating up. Whether you rotate the thermostat, if it's not keyed to a certain position, or not I think probably doesn't matter, as long as the thing is right side up.
That wouldn't be something that would get done since I took it apart and being mechanic for 50 years but have not run across a round thermostat that says "toward radiator" with an arrow.Looking at the diagram flow chart I would say I installed it correct with words in back pointing towards radiator but thought I would ask.I should have photographed the thermostat when I took it apart as I may have been able to see how it was factory installed but didn't think I would run into this?
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So does arrow on thermostat point to the back of motor or to the front of motor?There has to be a reason Ford put it on there as the original one was all brass and new one is part stainless but see no real difference in them?
It doesn't matter how the thermostat's clocked, as long as it's oriented correctly relative to coolant flow. The arrow's only to indicate which direction the thermostat should be pointing relative to coolant flow.
My apologies for not addressing that earlier; I didn't realize what you were talking about until now.
My apologies for not addressing that earlier; I didn't realize what you were talking about until now.
This is printed on the black rubber, correct? (RT-1049,E5TZ-8575-C) There should be three arrows pointing up. They indicate the flow of the coolant. It doesn't matter which way the printing faces, as long as the arrows point toward the thermostat housing.
Hydro-idi
Full Access Member
As long as the thermostat is put in correctly (rubber side down & tipped side up), it does not matter where that arrow is pointing. It does not need to be clocked a certain way for it to function properly, as long as it's not installed upside down.
