Originally Posted by Zjvdwerf12
Hey guys! Just bought a 2000 Ranger 2.5 the other day, and I noticed that the coolant temp seemed to only go up about a quarter of the way while driving through town. It would go up to about a third when stopped red lights, and drop to cold when going 55-60mph.
I purchased an aftermarket gauge that will read the actual temps and have replaced the stock gauge sender with the new gauge sending unit. I also replaced the thermostat at the same time with OEM 192*F.
The coolant temp after about 30 mins of running was about 160-170*F (measured at the radiator cap). I am unsure of how hot it is at the sending unit as I have yet to finish wiring it up.
I also have no heat while at idle, and it only blows warm air while moving, never hot. The upper and lower radiator hoses are hot, but not so much that it burns to touch them.
Is the next step to replace the water pump? Does anyone know what the proper coolant temp should be at the radiator cap? I would imagine it is more in the 180-200*F range. Any input is appreciated, this is my first ranger, as well as my first car that I own and was not given to drive!
Engine coolant temp should be at 190 after 5 minutes of driving 8 minute if just idling.
Fan Clutch could be stuck on, so there is too much air circulation.
Start engine cold, let it run for 30 seconds or so and then shut it off.
Try to spin the fan, it should spin easily, 2 or 3 full spins before it stops.
If it doesn't spin easily replace it.
The fan clutch has a bi-metal spring on the front that is warmed up by the radiator heat, so fan should spin freely until Rad gets warmed up.
A cooling system works like this.
Heater core and engine block/heads are isolated from the radiator by the thermostat.
The water pump circulates coolant(so not really a pump), in the direction of the upper rad hose and heater core hoses, but when thermostat is closed that coolant flows into the by-pass hose and back to the water pump.
So the upper rad hose should not get warm at all until thermostat opens, and that shouldn't happen until coolant behind the thermostat reaches 190degF.
The radiator is there to remove excess heat,
coolant that is hotter than 190degF, on very cold days the radiator might never be used, it is only there to get rid of excess heat, so radiator not getting hot can be very normal on cooler days.
And the fact is is getting hot may be the sign of a problem.
If your upper rad hose is heating up with the engine then thermostat is not working, upper hose should remain cool until temp gauge gets above 1/3, then thermostat might open a bit and pass warmer coolant to the rad and upper hose will start to warm up.
Thermostat often closes again as the cooler rad coolant flows into the engine from the lower rad hose, then thermostat will open again when coolant gets back up to 190degF.
The Ford Lima 2.xl engines do not generate alot of heat, this is why a bad fan clutch can make them run cold, lol.
In the winter people often put cardboard in front of the rad to stop almost all the air flow into engine compartment to keep heater working, lol.