Cooling Question - First Gen.

[Bronco648]

Ranger: 1985 RCLB, 2.8 V6, A4LD

This truck just went thru a mechanical restoration. Most parts are new/rebuilt or refurbished.

The 2.8 is off a fresh rebuild with less than 100 miles on it (currently). The t-stat the an o.e. replacement (192*). The radiator is a new, single core, o.e. replacement (coolant is fresh). The fan is electric and runs off of a 200* t-stat (edit: not a t-stat, a sending unit) in the water neck. Even with temps hovering around 32*, the engine gets pretty warm (needle is in the upper range of the gauge - caveats apply to 'gauges' in old Rangers, I know) and I can hear the fan kick on after about 4 miles of driving (local roads ~ 45 MPH). It will not cool the engine enough to kick off. Drive to work is 5 miles so I'm never really 'pushing' the cooling system. But, I wonder what will happen when summer rolls around.

Did I chose the wrong temp. stat? Should I switch to the other fan stat (185*)? Do I need a double core rad.?

 

[Shran]

Well you need an actual temperature reading to start with. Could be that it's simply getting up to temp like it should and staying there like it should.

I don't think I'd mess with a bigger radiator. My experience with replacing a single core with a double core is that the engine temp stays colder for longer in cold weather and makes very little difference in hot weather. I think there is a potential to hurt gas mileage in cold weather in EFI vehicles by doing that.

 

[RonD]

Ford dash temp gauges usually have 205degF as the center line, after warm up you should be just below 1/2 , 185-190degF

As said try to get an actual temp reading at upper rad hose after warm up, and check lower hose as well

Feel upper and then lower rad hoses after warm up
Lower should be 15 to 20degF cooler than upper if radiator has good flow

If temp switch for fan is in upper rad hose make sure its on the side or lower part so it stays immersed in coolant, upper hose often has some air at the top

Heater hoses are the water pump bypass, if heater core doesn't have good flow then engine will run warmer
Feel both heater hoses after warm up, both should be same temp if blower/fan is off, i.e. not pulling heat from core
If one hose is much cooler then heater core is clogged

Fan shroud needs to be in place on radiator, it cause fan to pull air thru radiator when stopped or driving slowly, without the shroud it doesn't pull air through radiator

 

[Angie]

are you talking about the bottom Tstat? are the 2 the same heat tolerances? because the top housing does not need a second Tstat. use this area for the sending unit for a "mechanical" gauge.

 

[RonD]

I thought only the 2.3l Duratec Rangers had lower rad hose thermostat?

 

[AndyB.]

There are different thermostats for 2.8s. The brass one on the right is the part for engines with the lower thermostat.

 

[Angie]

The 2.6-2.8 have a reverse flow style system where the housing is down under the water pump and there is a small bypass hose going up to the top housing. this bottom section is where the Tstat is to be placed.

 

[AndyB.]

The 2.6-2.8 have a reverse flow style system where the housing is down under the water pump and there is a small bypass hose going up to the top housing. this bottom section is where the Tstat is to be placed.

Yes and no. This was changed midway through the 1985 production year. Later models have a different intake, bypass hose, upper thermostat housing, and thermostat.

The engine in this post does have the earlier location.

 

[Angie]

andy, that is interesting, you have something I can read about this?

 

[RonD]

Lower thermostats would be 180degF to maintain 190degF in upper engine

 

[AndyB.]

andy, that is interesting, you have something I can read about this?

 

[Angie]

sorry andy, that doesn't say anything about a top Tstat. coolant enters an engine from the bottom of the block.

 

[AndyB.]

You’re right. I just made this up to post on the internet for funsies.

Here’s a picture of the updated thermostat housing and how the setup looks installed.

 

[Angie]

ok i stand corrected for the "funsies" here is a search on the part number you show....

E5TZ8592F - Ford Engine Coolant Thermostat Housing | Lakeland Ford Online Parts, Lakeland FL

Genuine Ford Part # E5TZ8592F (E5TZ-8592-F, E5TZ8592K) - Engine Coolant Thermostat Housing. Fits Aerostar, Bronco II, Ranger. Ships from Lakeland Ford Online Parts, Lakeland FL

parts.lakelandford.com

this to me wouldn't be a common part as ford went 2.9 soon afterwards.

and why didn't you just show me that part and number to start with? i learnt something today. thanks.

but i would venture not many have this part in thier truck. and what did they do down on the bottom of the inlets Tstat? vacant hole?

 

[RonD]

Shows as Upper on B2 and Ranger 2.8l

Lower rad hose is open to radiator but can only pull in coolant from radiator when there is flow out of the engine and into upper radiator, so thermostat open

There will be a bypass hose so water pump can pull in coolant while thermostat is closed
There are a few different plumbing arrangements used for this bypass
On newer models it was the heater hoses, upper engine out to heater core, return from heater core to water pump
Because the heater hoses are smaller there is less flow so engine warms up faster
When thermostat opens larger hoses can flow more coolant for cooling engine but not enough flow to cut off flow thru the bypass(heater core)