1999 2.5L engine temp not normal
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From: joliet
1999 2.5L engine temp not normal
Hello everyone, Just want to drop in and share my experience with my 99 Ranger 2.5. Ever since I owned the truck, I have had issues with warming up of the engine. The engine seems to take a long time to warm up to normal temp, usually requires I drive it a couple of miles before temp rises, even after idling for 5-10min in the driveway. Also, I noticed the temp dips down at stops and even drops to cool if parked long enough. I have tried cardboard, smaller radiator, swapping the thermostat and replacing the temp sensors. The cab warms up fine when the temp gauge reads halfway. The upper radiator hose also seems to correlate with temp readings. I'm going to assume the thermostat has failed, although it has less than 8k miles. Will swap it out this weekend and update my results.
Welcome to the forum
Yes, could be thermostat is not closing like it should when cold
You can do simple test for that
Start cold engine
Feel upper rad hose and heater hose at firewall
Let it idle for 2 or 3 min
Feel hoses again
Heater hose should be warming up
Upper rad hose should still be as COLD as it was before, if its warming up then thermostat is not closed like it should be
Also test fan clutch
Before starting cold engine spin the fan, it should be tight, will move but not spin, called cold locked
Start engine for above test
After the 2 or 3 min run time shut off the engine
Spin fan again, should spin easily, its unlocked
If it still feels tight replace fan clutch
Fan clutch uses oil inside and when its cold it feels the same as it should when locked
After start up and the water pump and blades spinning the oil warms up from friction and thins out, so it unlocks
On the front of the fan clutch is a by metal spring, this spring is warmed up by RADIATOR HEAT, as it warns up the spring expands and moves valves inside the clutch part which close off openings for the oil to pass thru slowly locking the fan so it spins closer to water pump RPMs and provides more cooling by pulling more air thru radiator and also blowing more air around the engine
If it fails in Locked position, which is its normal "fail safe" mode, then it will provide more cooling than is needed, especially at idle, it never unlocks
Yes, could be thermostat is not closing like it should when cold
You can do simple test for that
Start cold engine
Feel upper rad hose and heater hose at firewall
Let it idle for 2 or 3 min
Feel hoses again
Heater hose should be warming up
Upper rad hose should still be as COLD as it was before, if its warming up then thermostat is not closed like it should be
Also test fan clutch
Before starting cold engine spin the fan, it should be tight, will move but not spin, called cold locked
Start engine for above test
After the 2 or 3 min run time shut off the engine
Spin fan again, should spin easily, its unlocked
If it still feels tight replace fan clutch
Fan clutch uses oil inside and when its cold it feels the same as it should when locked
After start up and the water pump and blades spinning the oil warms up from friction and thins out, so it unlocks
On the front of the fan clutch is a by metal spring, this spring is warmed up by RADIATOR HEAT, as it warns up the spring expands and moves valves inside the clutch part which close off openings for the oil to pass thru slowly locking the fan so it spins closer to water pump RPMs and provides more cooling by pulling more air thru radiator and also blowing more air around the engine
If it fails in Locked position, which is its normal "fail safe" mode, then it will provide more cooling than is needed, especially at idle, it never unlocks
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bbrunke
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