Need help 2.9 1987 bronco 2 cooling issues

[Tactical Bronco 2]

My b2 is running hot but still in the normal range on the gauge the needle stays around the bottom of the o I can understand it running a little hotter with no fan shroud and body lift but here's the screwy thing I don't understand when I turn the heater on the heat rises ????? Also the thermostat was bad replaced it stays a little colder when I turn the heater on but still rises ???

Also I have a ? About thermostats I have been running a motor rad 180 fails safe last night I switched to a motorad 180 high flow what would you guys suggest for a semi built motor 160 180 192 high flow, oem or fail safe also what brand motocraft, motorad, stant or the jet performance thermostat

 

[RonD]

How old is the water pump?

The water pump circulates the coolant through the engine passages, when you "open" the heater core then that extra loop is added to the system, if water pump impellers are getting less efficient(electrolysis makes blades smaller) then that could explain why "turning on" heater causes rise in temp gauge, circulation thru the engine is slightly reduced.
Just guessing.

Could be a bad ground as well, my '94 rangers temp and oil gauge were both running higher, found that the ground strap from head to firewall was loose, cleaned and tighten.
Gauges went back to normal operation.


T-stat temp selection depends on your location for the most part.
An engine should run with coolant temp averaging 220deg, best gas mileage and oil lubrication(212deg) at that temp.
If you live in Southern Calif. you might want a 180deg t-stat since you are more likely to be running in warmer weather than colder.
If you live in Minnesota you may want to run a 192deg since you will be running in colder weather.

The suggested t-stat temp for an engine/model is the one to go with if you aren't running in outside temperature extremes, i.e. +90deg and less than 30deg
A few weeks of this is not an issue we are talking about months of +90deg or months of below freezing weather.

The suggested T-stat temp is the one designed for the engine and rad/fan system in that model to keep the engine in the sweet spot 220deg.

Running without the shroud changes the design so I would put on a shroud or switch to electric fan.

 

[dj1075]

If i were u i would check the timing if it is retarded the exhaust valve opens late retaining heat in the engine.

 

[fyre82]

The sensor will give you screwy readings as well as the voltage on the entire cluster. I have had oil and temp guages matchup and move to the same places. That solved with reestablishing the stock grounding, some were missing/inadaquate.

I solved it all with a set of aftermarket gauges on both of my 2.9 Rangers.
Now I know what is real and how the real readings relate to the dummy guages in the cluster.
You can look at that here:

http://www.therangerstation.com/forums/showthread.php?t=114625

Flush your radiator, inside and out. There is more stuff in the outside than you might imagine.

Rich