Cooling woes continue

yoyodyne · Post by **yoyodyne** » Sat Oct 27, 2007 5:10 pm

I swear..no car I ever had gave me fits with the cooling system like this Bronco has. 1984 model. Taking too long to warm up..no thermostat. Went to the parts store, they said a 195 degree thermostat was factory. Took it home, put it in, truck overheats. Bottom rad hose never got warm, stayed cold. When the truck had no thermostat, it took a while to get warm, but it never went higher than about halfway in the "normal" range. 195 degree thermostat, went past the H mark. Pulled thermostat out, heated a pan of water to 200 degrees, dropped the thermostat in, it functions fine. So, went back to the parts store, picked up a new water pump and a 180 degree thermostat. Truck still gets hotter than it should, just touching the H mark on the gauge. Bottom rad hose still is ice cold. Rad is clear, no problems with it. With a thermostat in, i never see any flow in the rad, looking in the filler neck. No thermostat, flows fine, never overheats. What is going on? Are they giving me the wrong style thermostat? The ones they are giving me has an extra washer and spring on the block end, it looks like it seats up against the hole in the rear water outlet housing, the one that has the little hose that goes to the upper water outlet, where the sensors are)The heater hoses get nice and hot, and when i squeeze them i can feel good flow in them. Any ideas? Besides taking out the thermostat and leaving it out,lol.

CraigK · Post by **CraigK** » Sun Oct 28, 2007 3:38 am

yoyodyne

I've never messed with my thermostat, but could you be installing it upside down? Maybe the bimetal functioning part is not on the engine side????

FYI - once winter comes, I have a large piece of cardboard (spray painted flat black) I put in front of my rad to reduce cooling capacity, speed warm-up and keep the temp up on my '87 B2. I usually don't have to remove it until late spring.

CraigK

yoyodyne · Post by **yoyodyne** » Sun Oct 28, 2007 8:00 am

you can't put the thermostat in wrong,lol. it fits only one way.

garagedude · Post by **garagedude** » Sun Oct 28, 2007 10:33 am

Do you have a mechanical water temp gauge. My 84 DASH gauge was always reading weird. Are you "burping your system" of ALL air after taking it apart? If you have a mechanical gauge you can see when its warming up or not warming up. Thats where I started with mine. My 84 warms up quick, and stays at 200 except when I'm pulling a trailer (1200 lb) up a hill then it starts climbing to 220. Ck if your burping your system first...

yoyodyne · Post by **yoyodyne** » Thu Nov 01, 2007 3:48 pm

There is a mech temp gauge, reads around 190 with no thermostat. Pegs over 220 with a thermostat. i am filling the collant using the procedure on the core support...taking off the upper radiator hose at the rad, pouring coolant in there,reattatching it, then into the radiator. I suppose there might still be air in there, but i don't know how. The spot on the block where the thermostat and the outlet necks are don't really get very hot, even when just a few inches away on the upper outlet where the temp sensors are is too hot too touch. The heater is blowing really hot, so I seem to be getting good flow there,too. The only thing iffy is the fan clutch, it is really stiff when cold, and it moves alot of air when cold,maybe it's keeping the front of the motor too cool? I am out of ideas,lol. I am thnking about going to the dealer and paying 27 bucks for one of their thermostats.

yoyodyne · Post by **yoyodyne** » Fri Nov 02, 2007 10:11 am

It seems that the Ford dealer parts book has different thermosats..one for Bronco II's made before 12/84 and after 12/84. The one for the later trucks is 10 bucks, the one for the earlier trucks is way more expensive. Autozone, Advance Auto, ect all show the thermostat as being the same.

Ruffinit · Post by **Ruffinit** » Fri Nov 02, 2007 1:43 pm

Hey! I've been working with 2 radiators out of '84s. Both of them were plugged so badly with dog gone radiator sealant that they couldn't flow.

Take the radiator off and take it down to a radiator shop and make sure that the thing flows.. Could just be that without the thermostat it could get just enough flow.. The '84s seem to run nicely cool natively.. Just a thought.. And DON'T let them power flush it in your BII without bypassing the heater core as specifically stated in the shop manual.

yoyodyne · Post by **yoyodyne** » Fri Nov 02, 2007 8:51 pm

The rad is flowing OK,took it off and had it checked...it looks to be one out of a later model Bronco II, as the previous owner rigged it in with wire ties. That's another project, finding the correct upper radiator mounts for when I do buy the correct rad in the future. The thing that bugs me, is how the lower rad hose is always cold, and the area around the t-stat is never as hot as the rest of the engine. I can burn my hand on the heater hose and upper outlet, but the lower one is no where near hot.The guy at the Ford dealer shows that there is a 1984 only thermostat listed in his parts book, and it is obsolete..going to cost me 57 bucks if i want it.

garagedude · Post by **garagedude** » Sat Nov 03, 2007 8:46 am

Dang, 57$ for a thermostat. I would take out the back seats and install a second radiator before I would pay that. I don't know what the deal is. Have you cked for a blockage in the engine itself?

Ruffinit · Post by **Ruffinit** » Sun Nov 04, 2007 6:52 am

Ok, good show. One more thing to check. Just for troubleshooting. Bypass your heater core. You can do this by just reconnecting one of the hoses. Remember that the heater core acts like a second radiator and if it isn't flowing, you may not get the proper cooling either.. The correct flow for this is from the intake to the passenger's side of the core, then from the driver's side of the core to the tube that takes it into the front of the engine.

I don't know anybody who goes out to get a thermostat that is specifically for an '84, and these all are running 24 years... If you want to double check on that, hit NAPA. That being said, this is what the Ford Shop Manual states, it is all caps and bold just like the manual, (figure shows the point on the thermostat going into the neck):

Position the gasket on the cylinder head opening. THE GASKET MUST BE POSITIONED ON THE CYLINDER HEAD OR THE INTAKE MANIFOLD BEFORE THE THERMOSTAT IS INSTALLED.
TO PREVENT INCORRECT INSTALLATION OF THE THERMOSTAT, THE WATER OUTLET CASTING CONTAINS A LOCKING RECESS INTO WHICH THE THERMOSTAT IS TURNED AND LOCKED. INSTALL THE THERMOSTAT WITH THE BRIDGE SECTION IN THE OUTLET CASTING. TURN THE THERMOSTAT CLOCKWISE TO LOCK IT IN POSITION ON THE FLATS CAST INTO THE OUTLET ELBOW.

Happy hunting!

Ruffinit · Post by **Ruffinit** » Sun Nov 04, 2007 7:00 am

Just read your initial post again. Sounds like your heater is acting like your radiator which is why it gets hot so fast. Without the real radiator, this makes perfect sense.. Silly question, but have you checked your hoses? Seems like lately I've had issues with rubber hoses collapsing on the inside and stopping flow. This has happened with cooling, brakes and fuel lines.

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