Coolant sensor replacement --- Where is it?

The temperature coolant sensor in your car is a replaceable part that cannot be repaired.
This part screws into your engine block.
You can buy a replacement on Amazon or on e-bay.
God bless your efforts.

The coolant sensor will look something like the image below. Usually, it is at the front of the engine, screwed into the block. Look for a brass portion screwed into the block

It will have -usually - one or two wires connected to it.

Hello and thank you for using Fixya. To replace the coolant sensor in your 2004 Hyundai Santa Fe, follow these steps below:

Find the coolant temperature sensor in the engine block on the driver side of the engine compartment. It is screwed into the block and has a wire lead running to the engine wiring harness. Once you locate the sensor, disconnect the wire lead going to the sensor with an open end box end wrench. Inspect the wire lead for melted insulation and discolored insulation. Either condition will require you to replace the wire lead. Make sure the engine has cooled enough to prevent burn injury. Use the appropriate socket and ratchet or open end box end wrench to loosen the temperature sensor. Turn the ratchet or wrench counter clockwise until the sensor is loose enough to turn by hand. Unscrew the sensor and remove from the engine block.Check the temperature sensor for corrosion and the wire lead for damage. Replace the sensor and reconnect the wire lead. Start the engine and allow it to heat up to operating temperature. The cooling fan should come on automatically as the engine temperature increases.Use a gloved hand to squeeze the input hose for pressure. If pressure exists, it means that the coolant is flowing to maintain the engine operating temperature. Now check your engine temperature sensor or warning light to see if it is reading properly.

The ECT (Engine Coolant Temp sensor) should be located by the coolant thermostat housing or where the upper radiator hose connects to the engine. It screws in with a plug or small/short wire harness attached to it. -------------------------------- To replace ect sensor:---

1. Drain and recycle the engine coolant.
2. Remove the intake manifold cover, if necessary.
3. Remove the exhaust crossover.
4. Disconnect the Engine Coolant Temperature (ECT) sensor electrical connector.
5. Remove the ECT sensor.

see fig below:---

.Thanks.

WELL YOU NEED TO DRAIN COOLANT LEVEL BELOW THERMOSTAT LEVEL.YOU HAVE TO DISCONNECT MAF SENSOR LOOSEN AIRDUCT 2 LARGE CLAMPS LOOSEN REMOVE 4 SCREWS TO AIR FILTER COVER LIFT UP REMOVE COVER. THEN REMOVE AIR FILTER AND HOUSING, FIRST DISCONNECT MAF SENSOR.YOU HAVE TO DISCONNECT THROTTLE CABLE AND SHIFT CABLE.YOU HAVE TO DISCONNECT REMOVE THROTTLE BODY COOLANT HOSES DISCONNECT IDLE SPEED CONTROL VALVE CONNECTOR AND DISCONNECT TPS SENSOR CONNECTOR. THEN REMOVE THROTTLE BODY ASSEMBLY. YOU NEED TO BUY NEW THROTTLE BODY COOLANT HOSES AND NEW THROTTLE BODY GASKET FOLLOW TOP COOLANT HOSE TO ENGINE BLOCK.NOW YOU SEE CAN AND REMOVE THE THERMOSTAT HOUSING REPLACE THE THERMOSTAT.BESURE TO HAVE EXTRA COOLANT ON HAND.BLEED COOLANT SYSTEM WHEN DONE.TO BLEED COOLANT SYSTEM REMOVE RADIATOR CAP ON OVERFLOW JUG.THEN OPEN BLEED SCREW ON THE WATER PUMP BYPASS HOSE PIPE JUST A LITTLE.POUR COOLANT IN THE OVERFLOW JUG UNTIL LEVEL STOP DROPPING.STOP AT COLD MARK ON JUG.CLOSE BLEEDER SCREW ON WATER PUMP BYPASS HOSE PIPE.CRANK VECHICLE CHECK FOR LEAKS. START UP ENGINE LET IDLE FEW MINUTES THEN CHECK COOLANT LEVEL ADD MORE UNTIL UNTIL LEVEL STOP DROPPING.PUT RADIATOR CAP BACK ON OVERFLOW RESERVOIR. LET ENGINE IDLE WATCH COOLANT TEMPERATURE GAUGE.WHEN GAUGE START CLIMBING. TURN OFF ENGINE WAIT FEW MINUTES TAKE A LARGE RAG OPEN RADIATOR JUST A LITTLE YOU HEAR HISS NOISE.WHEN PRESSURE STABILIZE DONT GET SCALDED BECAREFUL.OPEN CAP LITTLE MORE.IF COOLANT PRESSURE STILL BOILS OUT WAIT 20 MINUTES ADD MORE COOLANT TO RADIATOR OVER FLOW WHEN COOLANT LEVEL STOP DROPPING.PUT RADIATOR CAP BACK ON START VECHICLE UP LET IDLE UNTIL THERMOSTAT OPEN. THEN FEEL TOP RADIATOR HOSE FEELS HOT THERMOSTAT OPEN WATCH TEMPERATURE GAUGE.IF GAUGE TEMP START CLIMBING TURN OFF ENGINE WAIT A WHILE.CHECK AND ADD MORE COOLANT.WHEN THE ENGINE CAN IDLE TEMP GAUGE STOP CLIMBING YOU HAVE BLEED COOLANT SYSTEM.KEEP CHECK ON COOLANT LEVEL.

Hi welcom to fixya. A defective knock sensor may cause engine detonation or reduced spark advance and fuel economy. When a knock sensor is removed and replaced, the sensor must be tightened to its specified torque. If the knock sensor is installed tighter than it should be, it may become too sensitive and provide an excessively high voltage signal, resulting in more spark ****** than required. When the knock sensor is installed looser than it should be, the knock sensor signal will be lower than normal, resulting in engine detonation.
To replace the knock sensor:

• Disconnect the knock sensor wiring connector.
• Then, unscrew the sensor.
• Remove the knock sensor.
• Reverse the procedures to install the part.
• 15 ft.lbs.torque
• hope this helps.Thank You for using fixya..iluv2fish.. Ray..

P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control
Replace your coolant temp sensor.Be sure to double check your coolant level and does the engine reach an operating temp(about halfway on the guage)in a normal time?! If it does, the temp sensor for the computer needs to be replaced.

the coolant level sensor is malfunctioning. this should be either on the resevoir or screwed into the side of the radiator. inspect to see if there is one in the resevoir. if so, disconnect it and turn the vehicle on to see if the light goes out. if so replace it. if it is in the radiator, replace it. ther eare no "fixes" for these items.

Coolant Temperature Sensor/Switch (For Computer): Service and Repair
ENGINE TEMPERATURE SENSOR
Removal




Engine temperature sensor, 5-cylinder
Jack up the car.
Remove protection cover from under engine.
Drain the coolant.
Lower the car.
Release coolant hose from thermostat housing using pliers.
Remove thermostat housing.
Remove sensor.




Engine temperature sensor, 6-cylinder
Jack up the car.
Remove protection cover from under engine.
Drain the coolant.
Lower the car.
Loosen oil reservoir for servo pump.
Remove coolant reservoir and put it to one side.
Remove screws and outer/upper timing-gear casing.
Remove screws and wire channel.
Disconnect connector.
Remove 4 screws and thermostat housing.
Remove sensor and wires.
Installation
Engine temperature sensor, 6-cylinder
Install thermostat housing sensor.
Position wires in slot on thermostat housing.
Note! The white marks should be positioned in lower opening of slot, from underneath.
Position gasket on thermostat housing correctly and install thermostat housing using two of the screws.
Position thermostat housing correctly and tighten the four screws.
Position wire channel correctly and position wire in channel.
Tighten screw on wire channel.
Connect the connector.
Install outer/upper timing-gear casing.
Install coolant reservoir.
Install oil reservoir for servo pump.
Follow-on work, 6-cylinder
Fill up coolant.
Warm the engine until the thermostat opens.
Switch engine oft and check the level. Re-fill if necessary.
Check for leaks.
Check in VADIS vehicle communication (read-out of parameter values), for current engine system, that the engine temperature shown appears
correct.
Engine temperature sensor, 5-cylinder
Install in reverse order.
Follow-on work, 5-cylinder
Fill up coolant.
Warm the engine until the thermostat opens.
Switch engine off and check the level. Re-fill if necessary.
Check for leaks.
Check in VADIS vehicle communication (read-out of parameter values), for current engine system, that the engine temperature shown appears
correct.

NON-FSI PETROL ENGINES,THE SENSOR SWITCH IS SCREWED INTO THE OIL FILTER HOUSING,REMOVE THE ENGINE TOP COVER.UNBOLT THE COOLANT EXPANSION TANK MOVE TO ONE SIDE .THERE NO NEED TO DISCONNECT COOLANT HOSES.AND DISCONNECT WIRING PLUG FROM SENSOR.UNSCREW SENSOR.....FSI ENGINES REMOVE THE INTAKE MANIFOLD TO GET AT SENSOR....DIESEL ENGINES THE OIL PRESSURE SENSOR IS SCREWED INTO THE OIL FILTER HOUSING ASWELL.PRISE OUT THE CAPS,UNDO THE NUTS AND REMOVE THE PLASTIC COVER ON TOP OF ENGINE.REMOVE THE INSULATION BENEATH COVER (WHERE FITTED).DISCONNECT WIRING PLUG FROM SENSOR AND UNSCREW......BE PREPARED FOR OIL SPILLAGE.. HAVE A NICE DAY!!