1989 Bronco II 2.9 Auto Runs Hot


TXBII

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Vehicle Year
1989
Make / Model
Ford
Engine Size
2.9 for now..
Transmission
Automatic
My BII seems to have always run on the hot side. Does it especially climbing trails and in high altitude. Also pretty regularly during the summer driving long distances or around town. I replaced the radiator a few years ago but it never really fixed the issue. It has the flex-a-lite electric fan setup for the Bronco II/Rangers and I also added a pusher fan on the front which helped some but the temps will still climb up to 220 if I am not careful. Which sucks to have to pull over almost after ever run. It acted the same with the manual fan clutch setup as well, even replaced the fan clutch before I went to the electric setup. What do you all think is the issue? Would a 2 row 4.0 Ranger radiator fix the problem? I was thinking about replacing everything, get a 4.0 2 Row Radiator, new Water Pump, new Heater Core, and new 180 degree Thermostat. On the 4.0 Radiator, would I get a 1990 Ranger 4.0 Radiator for Automatic with A/C? Thanks for any help, thoughts, or recommendations.
 


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wildbill23c

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Location
Southwestern Idaho
Vehicle Year
1988
Make / Model
Ford Bronco II
Engine Type
2.9 V6
Transmission
Automatic
2WD / 4WD
4WD
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0
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205/75-R15
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Do you have an auxiliary transmission cooler? If not add one, that's part of your problem. I have a radiator out of a 4L explorer in my 88 B2, and the stock thermostat which is a 192 degree. I run right around the 195-200 degree mark normally even with the AC running. They run warm it seems like regardless. Part of the issue is the engine is jammed in under the hood with inadequate airflow I think. I have the heavy duty fan clutch on my Bronco 2 so it engages and stays engaged far more often than the stock clutches do.

I can't really say for sure why they run hot but having an automatic transmission with the cooler that runs through the radiator is useless, and causes both the engine and transmission to run much hotter, adding an auxiliary transmission cooler is a huge help, and install the largest transmission cooler you can fit.
 

PetroleumJunkie412

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1988
Make / Model
Ranger
Engine Type
2.9 V6
Transmission
Manual
2WD / 4WD
4WD
I had way bigger temp problems with mine when I ran my dual pusher fans and single puller together. They would overcool the coolant and the thermostat wouldn't open.

Also hand problems with start thermostats. Went to a different brant (MotoRad?). Ended my troubles.
 

RonD

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I assume you checked temperature with a different device and not just going by the dash gauge?
Have to ask :)

Does the over flow system seem to work?
Coolant should flow over to the tank and fill it to hot line and then suck that coolant back in after engine cools down(engine off)

That keeps radiator topped up, check level when cold, should be full to the top NO AIR at all
If not then rad cap may be bad or overflow hose is cracked, sucking in air when cooling down

Yes, double core is best, more coolant volume is better than less

Also if heater core gets partially blocked it can cause warmer running because of blocked flow in water pump
 

mperry

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1994
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I like RonD's suggestion of checking the actual temp. The factory gauge can be off due to age, or corrosion, or the sender could be defective.
I'd pull the thermostat and drop it in a pan of water, bringing it to a boil. Use a meat thermometer to test the temp when the thermostat opens... or simply swap it. They aren't expensive, but you want one of quality, maybe NAPA or Ford.
I'm guessing your water pump fins are corroded. I've seen younger trucks w/ inadequate water flow due to fins corroded down. It's been 20 years. Pull and inspect. A gasket is cheap. If a high flow is available, it sounds like yours could use it. (This is especially so if a former owner liked to run straight water.)

A heavier radiator could be in line and especially, as said, an oil cooler. The factory unit was barely adequate for hard work. When it does overheat, you can turn the heater (full hot, full fan). You'll roast but the engine should drop in temp.
I'd also check the fan. I know this sounds dumb, but make sure the electric is blowing in, not out. If on a thermostat, make sure it turns on at the proper temp. (Some people wire them manually.) On your flex fan, I was going to say to check the clutch. I know one person who has an electric mounted in front of the radiator, stock behind. He says it pulls additional air, when he's caught in traffic. (Makes sense.)
Since it's been a couple years, a radiator flush might be in line.

That's my thoughts. My old '94 works hard then sits in 100+ degree temps, AC blasting, at in the normal range.
 


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