Thermostat?

[NPdarkside21]

So to make a long story short, after weeks of working on my cooling system and changing many of the engine gaskets, I've noticed that my temperature gauge gets a little high. Had the water pump tested and everything works. brand new hoses, fittings, and temperature sensor and still feels like the engine is hotter than normal. the upper radiator hose also gets extremely hot so my only guess is a bad thermostat. Any input?

 

[cbxer55]

Changed mine out to a 180 years ago. Not been a problem yet, even in the winter.

On mine the temperature gauge needle is usually about 3/8 of an inch up from the bottom mark. Also the upper radiator hose is going to feel hot, the stock thermostat is a 195. There is a coolant temperature sensor by the thermostat housing. I believe if the temperature was too high, you would get some kind of code from the computer on that. I know you can get one for being too low. Tried a 160 thermostat once, and during the winter got the code saying something like "coolant temperature not high enough for computer to make the switch from OPEN LOOP to CLOSED LOOP. Never got that with the 180, and it's been in there since like 2004 of 5.

 

[RonD]

Yes, 190-195degF is stock Ford thermostat rating, gets best MPG and keeps oil cleaner.

Ford temp gauge shows approx. 210degF as center line, so should run just below center line when fully warmed up, just above center line when climbing a long hill or pulling trailer, 220degF

Start of Overheating is when coolant temp gets above about 240degF
A 160deg, 180deg or 195deg thermostat would be fully open at that point so a working thermostats has nothing to do with overheating.
It is there to get engine up to operating temp as soon as possible, this makes engine last longer
3.0l Ranger thermostat has the same opening size regardless of temp rating, a 160deg thermostat has the same flow rate when open at a 195deg or 208deg, 160deg just has less wax so it melts sooner and thermostat opens at a lower temp.

Radiators are for EXTRA heat, if very cold out they may never even be used on some engines.

Upper rad hose and lower rad hose, after warm up, on the 3.0l should be about 15-20deg difference in temp.
If upper hose is much hotter than lower hose then radiator is clogging up or water pump is not circulating coolant very well.
It could be thermostat is not opening all the way, it can happen, but when they fail they usually fail wide open, a "fail safe" setup, so engine takes too long to warm up.

 

[Angie]

Any input?

There are 2 tools i have hanging in my shop, one is like this,

https://www.amazon.com/Etekcity-Lasergrip-774-Non-contact-Thermometer/dp/B00837ZGRY/?tag=959media-20

and the second one is a mechanical temp gauge with a "T" , or just fully plumb in and bypass the factory one.

have you tried these 2 items to make sure that you are actually hotter than normal? or just guessing it feels hotter?

 

[wildbill23c]

Bad thermostat, fan clutch possibly bad, air in the cooling system.

I'm currently trying to figure out a similar problem with my 88 Bronco 2. Sometimes it is fine, other times it starts getting hot, doesn't overheat, but temp starts climbing pretty good and has a hard time cooling back down.

I have a radiator that has a slight leak on the passenger side of the tank, kind of thinking that is part of the issue since the system doesn't stay pressurized properly so it can't work properly. Also, when it heats up the fan clutch never seems to actually engage still seems to be in more of a freewheel.

Start checking things out, leaks, fan clutch (not sure how you actually test one), if there's air in the system it can cause it to heat up and actually overheat pretty quick, may not be the case here if it never overheats.

One other thing that comes to mind. If your truck has an automatic transmission, is it shifting properly? If not, if its hanging out in the wrong gear, not downshifting to 1st at a stop, it can cause the truck's engine to run hotter as its trying to compensate for the transmission not shifting properly...my bronco 2 was doing this after the transmission rebuild as the valve body wasn't operating properly so it was running in 2nd gear and 3rd gear.

 

[Kurt.king870s]

You could also check the radiator cap, my buddy had an f250 that started running hot and one night got up around 260.......he got a new cap and it returned to where it should be. And has stayed there for several nonths.......and that would be cheap to replace too, I always hate to buy a big thing first an find out it was something cheap like that.

 

[cbxer55]

While it MAY be true that a 195 keeps the oil cleaner and makes the engine last longer, I've only read that the 195 is used because of the requirement for the engine to reach a certain temperature so the computer can make the switch from open loop to closed. Guys over on one of the LIGHTNING forums I frequent, put 160's in their trucks and re-tune the computer to work properly with them (no Check Engine Light).

As I said, I've has a 180 in mine sine like 2004, 13 years and over 100,000 miles. As for the oil being cleaner, my sister had this truck from Dec. 2009 to Sep. 2013. She put over 40,000 miles on it. So four years and 40,000+ miles later, I finally get it back from her, she never changed the oil once in all that time. And my findings, NOTHING. All cylinders are good on compression, no funny knocking noises under or anywhere in the engine. So it did no harm.

Also, I've used full 20W-50 in this truck since I bought it with 10,000 miles on it in 2001. Never used anything less.

So, in the end, I am calling b.s. to hotter being better for anything. At a ripe old 55 years old, I've always been told, and always believed, that cooler is better. And never had anything untoward happen to prove that wrong. Except a check engine light for using a 160 thermostat in a computer controlled vehicle. Never happened back in the days of carburetors and distributors. I always changed the thermostats on any vehicle I bought to a 160. Had a 78 455 Trans AM for years with a 160 in it, ran AWESOME. Had two Nissan "Z" cars with 160's in them. A Mitsubishi 3000 GT VR4 as well.

It's got very near 148,000 miles, is 19 years old, has had a 180 for 13 years, and used 20W-50 for ay years. Years ago, a cat here tried arguing with me BIG TIME that it was a mistake to use 20W-50. I use it in all my vehicles, including my 2004 Lightning, which is supposed to be a 5W-20 truck. Hasn't hurt a thing, except maybe fuel mileage. The whole purpose of the colored water oil is so companies can meet their CAFE requirements. No other reason to use colored water in your crankcase.

BYE-BYE now.

 

[wildbill23c]

You could also check the radiator cap, my buddy had an f250 that started running hot and one night got up around 260.......he got a new cap and it returned to where it should be. And has stayed there for several nonths.......and that would be cheap to replace too, I always hate to buy a big thing first an find out it was something cheap like that.

That was the first thing I replaced on my bronco 2, but when the radiator itself has a small leak it don't help much LOL...I'm pretty sure the radiator leak is my main source of trouble...it don't overheat but it gets pretty hot. I ordered a larger radiator and hoping it fits, although I realize now that the current radiator is bolted to the inside of the radiator support where the new radiator I need to get the brackets that go over the radiator support...so back to pick a part again HAHA

 

[McCormack]

Yes, 190-195degF is stock Ford thermostat rating, gets best MPG and keeps oil cleaner.

When I changed the T-stat in my '00 from the stock Ford 197* 'stat to a 180*, my truck ran a bit crisper and my fuel mileage went up a bit. I also believe that my engine will last longer at 180* because my oil isn't as thin as at 197*, and hoses and belts and what-not will also last longer because they're not subjected to the extra heat (when I used to open my hood with the 197* 'stat it was like an oven in the engine compartment... that's hard on rubber and plastic components).

 

[RonD]

Laws of physics is what you need to argue with not me, lol.

160 or 180 t-stat WILL give you a bit more power, keeps the intake cooler and cooler air allows for more fuel added.
This is why engines have a bit more power(pep) in the winter than in the summer, cooler air
And this was a trick the Cold Air Intake(CAI) guys used to sell their products.
"Also install a 160 or 180 t-stat with our product"

Coolant temp at or near 200degF means best efficiency in gasoline engine combustion, from the testing Ford did.

And running the oil a bit hotter burns off more contaminants, just physics

Nothing at all wrong with running 160 or 180deg t-stat, it is YOUR engine, but certainly not the ONLY option or IMO the best option when looking at the actual data from the testing by Ford and SAE, it is out there to look at

 

[JP02XLT]

As for the thermostat temp discussion, The Whipple kit has a 160 stat in their kit, on the dyno @ 20 psi of boost my truck made more HP on a 185 stat, that the motor temp was actually 187-188.
The truck was tuned for both stats, it just made more power on the 185, that is what I run year round now, as I used to change to a 195 stat for winter and back the boost down a bit as you could tell the difference in the heat in very cold weather.


JP02XLT

 

[cbxer55]

I use a 180 all year long, and the heat is fine for me in the winter.

Another thing I did years ago was remove the two hoses from the barbs on the throttle body. Of what benefit is it to heat the throttle body up using hot coolant? Seems counter-productive to me. First we try and get the intake air as cool as possible. Then heat it up at the throttle body? RIGHT!!

 

[wildbill23c]

I use a 180 all year long, and the heat is fine for me in the winter.

Another thing I did years ago was remove the two hoses from the barbs on the throttle body. Of what benefit is it to heat the throttle body up using hot coolant? Seems counter-productive to me. First we try and get the intake air as cool as possible. Then heat it up at the throttle body? RIGHT!!

I think it was actually meant to heat up the intake faster to get the vehicle into closed loop for emissions reasons, but yeah umm by the time the coolant is warmed up so is the vehicle LOL.

 

[cbxer55]

I think it was actually meant to heat up the intake faster to get the vehicle into closed loop for emissions reasons, but yeah umm by the time the coolant is warmed up so is the vehicle LOL.

Aside from that, most of the time I don't even drive mine until the temp. gauge needle is moving on it's way up. My drive to work and home is short, and it's just not good to do too many short trips that don't get the oil hot enough to burn off the unwanted stuff that gets into it. So I warm it up good before moving.

I also have one of them fancy "CAI's.". But I perforated the sheet metal under the hood in the area where the filter resides to where it looks like swiss cheese. During the winter, the filter never even gets warm.

 

[McCormack]

Laws of physics is what you need to argue with not me, lol.

Book learning and real world experience are two different things, lol. Once you've actually run a 180* T-stat in your truck, then get back to us.