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I was starting my ranger today to let it warm up. Came out 15 min later and saw the temp was reading high. Topped off the coolant and decided to drive it a bit to try to get the air to help cool in case the clutch fan was out. It didn't come down so I hopped into my other beater to get to work and figured I'd look at it when I got home. 8 hours later I'm still reading this high so I'm assuming I have a coolant temp sensor out. Anyone got a good diy video for this or a guess for what else it could be.
Any recent maintenance work or changes?
Coolant level in Radiator & OverflowTank?
How long since last Coolant system Drain+Flush+ReFill?
How old is ThermoStat?
Your OBD2 Scanner shows CoolantTemp -7c = below freezing; is your ambient temp below freezing?
May be a bad TempSensor or broken\shorted wire to TempSensor; take a look?
Believe your 2002 Ranger V6~4.0L~SOHC has same two TempSensors as my 2001, mounted in the ThermoStatHousing?
Sensor with BrownPlug+OrangeHarnessSocket is to InstrumentCluster TempGage only; should measure about 12kOhm @32f 0c in IceWater.
Sensor with GrayPlug+GrayHarnessSocket is to PCM\EngineControls\OBD2Scanner; should measure about 104kOhm @32f 0c in IceWater.
These two TempSensors are NOT interchangable; the Plug keys should NOT be trimmed\modified. Click here for more info on ThermoStatHousing & TempSensors.
FanClutch test:
~ With Engine Stopped+Cold, Fan should be relatively stiff to rotate by hand, Clutch engaged.
~ Cold Engine start+run for 1min then shutoff: Fan should be easier to rotate by hand, Clutch disengaged.
~ Start+Drive for 15min then shutoff Engine: Fan should again be relatively stiff to rotate by hand, Clutch engaged.
Hopefully this helps.
Last edited by DILLARD000; Mar 8, 2022 at 12:49 AM.
Any recent maintenance work or changes?
Coolant level in Radiator & OverflowTank?
How long since last Coolant system Drain+Flush+ReFill?
How old is ThermoStat?
Your OBD2 Scanner shows CoolantTemp -7c = below freezing; is your ambient temp below freezing?
May be a bad TempSensor or broken\shorted wire to TempSensor; take a look?
Believe your 2002 Ranger V6~4.0L~SOHC has same two TempSensors as my 2001, mounted in the ThermoStatHousing?
Sensor with BrownPlug+OrangeHarnessSocket is to InstrumentCluster TempGage only; should measure about 12kOhm @32f 0c in IceWater.
Sensor with GrayPlug+GrayHarnessSocket is to PCM\EngineControls\OBD2Scanner; should measure about 104kOhm @32f 0c in IceWater.
These two TempSensors are NOT interchangable; the Plug keys should NOT be trimmed\modified. Click here for more info on ThermoStatHousing & TempSensors.
FanClutch test:
~ With Engine Stopped+Cold, Fan should be relatively stiff to rotate by hand, Clutch engaged.
~ Cold Engine start+run for 1min then shutoff: Fan should be easier to rotate by hand, Clutch disengaged.
~ Start+Drive for 15min then shutoff Engine: Fan should again be relatively stiff to rotate by hand, Clutch engaged.
Hopefully this helps.
No recent work that would effect the coolant system. Level in the radiator was normal but a little low in the overflow. Been about a while since I flushed the system and I haven't had to change the thermostat yet. The ambient temp from the obd is spot on which is why I too think it's a short going to my cluster. I'll get to it this weekend and keep ya posted. Thank you!
Yep, keep us updated. Items to consider:
~ Only MotorCraft TempSensors, cheap OffBrands are known to fail early; new HarnessSockets with WiringTails are available if needed.
~ Drain+Flush+Renew Coolant every 4~5Yrs\33Miles: swap 5/8"Hoses@FireWall to reverse HeaterCore flow.
~ Renew ThermoStat + RadiatorCap every 4~5Yrs\33kMiles, only MotorCraft\Stant.
~ Replace junk Plastic ThermoStatHousing with Aluminum version at first TStat change; change both TimingTensioners while TStatHousing is off.
~ Renew AllHoses+SerpBelt+Fan+Clutch every 10~12Yrs\100kMiles, Continental#Elite Belt & quality WormClamps recommended.
~ Replace junk 2WayPlastic HeaterBallValve with 2WayMetal PlugValve when replacing 5/8"HeaterLoopHoses.
~ Replace junk PlasticTanked 2RowCore Radiator with AllAluminum 3or4RowCore Radiator when first replacing 1.5"RadiatorHoses.
~ Renew 3/8"HydraulicHoses+WormClamps in Radiator~TransCooler ATFLoop when replacing Radiator.
