2.5L ('98-'01) What should my engine coolant temperature be?

[Alam0]

Recently found out my engine coolant temperature sits around 165-167 Fahrenheit fully warmed up. Is that normal or should it be hotter? Also my temp gauge sits below the cold line.
(It's a 98 2.5l 4 cylinder)

 

[RonD]

Depends on outside temp, the 4cyl Lima engines bleed alot of heat, they weight 400+ pounds so lots of metal
In Northern areas people with these engines often put cardboard in front of radiator to keep engine and heater at warmer temps, lol

If you are using the OBD2 ECT sensor's temp reading I would expect 180deg+ with a 190deg thermostat
On dash gauge should be above 1/3 closer to 1/2, 1/2 is about 200deg on Ford gauges

Thermostat may be opening a bit too far
OR
Fan clutch is locked all the time so over cooling the engine bay and radiator

Before starting cold engine, open the hood and spin fan blade, should be hard to spin, cold locked
Start engine and count to 20, shut off engine
Spin fan again, should move easily, its unlocked, as it should be

Fan clutch is heated up by Radiator heat, so fan should stay unlocked until radiator starts to get hot then it will slowly start to lock to move more air
If outside air temp is cold radiator may never heat up hot enough for fan clutch to lock at all

 

[Alam0]

Depends on outside temp, the 4cyl Lima engines bleed alot of heat, they weight 400+ pounds so lots of metal
In Northern areas people with these engines often put cardboard in front of radiator to keep engine and heater at warmer temps, lol

If you are using the OBD2 ECT sensor's temp reading I would expect 180deg+ with a 190deg thermostat
On dash gauge should be above 1/3 closer to 1/2, 1/2 is about 200deg on Ford gauges

Thermostat may be opening a bit too far
OR
Fan clutch is locked all the time so over cooling the engine bay and radiator

Before starting cold engine, open the hood and spin fan blade, should be hard to spin, cold locked
Start engine and count to 20, shut off engine
Spin fan again, should move easily, its unlocked, as it should be

Fan clutch is heated up by Radiator heat, so fan should stay unlocked until radiator starts to get hot then it will slowly start to lock to move more air
If outside air temp is cold radiator may never heat up hot enough for fan clutch to lock at all

Turns out I had air in the coolant system and had to purge it. Got pretty much all of the air out, but that didn't seem to help. While purging the air I noticed the HVAC
Heater Control Valve had a lever. I pumped the lever a couple times and after a few pumps, the heater core inlet/outlet hoses got hot. Went to look at
the temp gauge and sure enough it was at operating temp (182deg Fahrenheit). Not only that but my hot air came back. Thanks for the feedback, I just thought I should let
you know what fixed my problem.

 

[DILLARD000]

If you've got the junk Plastic HeaterValve, the VacToClose BallValve pictured below,
it can be easily replaced with an old fashioned AllMetal VacToClose PlugValve, pictured below: FourSeasonsFactoryAir# 74603
The FordOEM Plastic valve is notorious for cracking+leaking.

 

[RonD]

I wouldn't use the single hose valves to replace the dual(4) hose valves as that could lead to random overheating since Ford uses heater hoses as the water pump bypass so both hoses need to maintain flow, either thru the heater core or thru the dual hose bypass valve, a single valve would cut off all flow when used

You can just install 2 couplers in place of the bypass valve and plug the Grey vacuum hose

The bypass valve is ONLY used in MAX AC setting to reduce heat in the cab from heater core coolant circulation which "might" lower cab temp, maybe 1 or 2deg
The biggest advantage of MAX AC is closing off Outside Air Vent, and recirculating already cooled Cab Air
If outside air is 90+deg and inside cab air is 80deg to start, then you already have 10deg cooler air which is cooled even more by AC than the 90deg outside air would be
And as cab air gets cooler then even better cooling of already cooled air