Its overheating replace thermostat and temperature sensor

There could be a few different issues that could cause the temperature gauge on your 2008 Ford Focus to read hot when the engine is not actually overheating. Here are a few things to consider:

Failed thermostat: The thermostat is responsible for regulating the flow of coolant through the engine. If the thermostat is stuck in the closed position, it could cause the temperature gauge to read hot even though the engine is not overheating.

Failed temperature sensor: The temperature sensor sends a signal to the temperature gauge to indicate the engine's temperature. If the temperature sensor is faulty, it could cause the temperature gauge to read hot even though the engine is not overheating.

Wiring issue: If there is a problem with the wiring that connects the temperature sensor to the temperature gauge, it could cause the gauge to read hot even though the engine is not overheating.

To determine the cause of the issue, it may be necessary to perform some diagnostic tests and possibly replace some components. A mechanic or a professional auto repair shop will be able to diagnose the problem and recommend the appropriate repairs. It's also a good idea to keep an eye on the engine temperature and take note of any other symptoms or issues you may be experiencing. This information can help the mechanic diagnose the problem more accurately

have you tried to check overheat gauge?? some temperature sensor? isn't that faulty?? I don't mean thermostat, but sensor...

is it really overheating, or gauge is showing overheating???

long time ago I had car that had same problem.... never overheated, but still signalized high temperature.....that time it was temperature sensor probably not compatible with correct one ....

Have you replaced the temperature switch sensors?
Most Mazdas and cars now days have a temperature sensor and a thermostat sensor that will operate the two fans on different temperatures/settings... Good luck!

Bad temperature sensor or bad connection to the temperature sensor

sound like thermostat sticking close.replace thermostat and radiator pressure cap.if already done.you could have faulty water pump.if engine overheating at long slow traffic line or setting at a stand still.the engine cooling fans should be running, check and see if cooling fans running if not,check cooling fans fuses and relays.if all is good,hot wire make sure coolings fans okay.if all is good,code scan vechicle for faulty engine coolant temperature sensor and ecm problems.you need a code scanner where you can check live data check see if coolant temperature sensor reading correctly if engine coolant temperature is 190 degrees the coolant sensor. the scanner suppose to show 190 degrees in temperature if not it reads 80 or 90 degrees the engine coolant temperature sensor is faulty need replacing.if all is good check engine oil if look like milk shake blow head gasket will cause over heating.to be on the safe side i would replace thermostat and radiator pressure cap first.to make sure engine coolant circulating through radiator and engine block.

OVERHEATING CAN BE CAUSE BY MANY THINGS LIKE FAULTY THERMOSTAT AND FAULTY RADIATOR PRESSURE CAP,TOO MUCH WATER IN COOLANT SYSTEM NEED 50 / 50 WATER AND ANTIFREEZE.LOOK FOR WATER PUMP WEEP HOLE LEAK, IF COOLANT LEAKING OUT WEEP HOLE WATER PUMP BAD NEED REPLACING.CHECK FOR LOW COOLANT LEVEL, YOUR RADIATOR OVERFLOW JUG SHOULD HAVE COOLANT AT THE FULL COLD MARK IF NOT KEEP ADDING COOLANT INTO COOLANT OVERFLOW JUG UNTIL COOLANT STOP DROPPING AND FULL COLD MARK, IF OVERFLOW COOLANT JUG WAS EMPTY RADIATOR IS LOW ON COOLANT.WHICH CAUSE AIR IN COOLANT SYSTEM KEEPING THE ENGINE COOLANT TEMPERATURE SENSOR FROM BEING SUBMERGE IN HOT COOLANT WHICH TURN ON THE COOLANT FANS.WHEN ENGINE COOLANT TEMPERATURE GET CERTAIN SET TEMPERATURE LIKE 190 DEGREES THE PCM AND COOLANT SENSOR WILL TURN ON COOLANT FANS, IF VECHICLE OVERHEATING COOLANT FANS NOT WORKING EITHER YOU HAVE FAULTY ENGINE COOLANT TEMPERATURE SENSOR CHECK COOLANT FANS FUSE AND RELAYS. YOU CAN CODE SCAN CAR TO SEE IF YOU HAVE FAULTY PCM, FAULTY ENGINE COOLANT TEMPERATURE SENSOR OR FAULTY COOLANT FAN RELAY.IF COOLANT FAN AND ENGINE COOLANT TEMPERATURE SENSOR OKAY,YOU HAVE CORRECT COOLANT LEVEL IN COOLANT SYSTEM, THERMOSTAT AND RADIATOR PRESSURE CAP BEEN REPLACED, YOU COULD HAVE BLOWN HEAD GASKET CHECK ENGINE OIL LOOKS LIKE MILK SHAKE HEAD GASKET BLOWED ALSO WHEN HEAD GASKET BLOWED YOU CAN DRIVE CAR SHORT DISTANCE START OVERHEATING AND YOU LOOSE ENGINE POWER SUSPECT BLOWED HEAD GASKET.

Do you think that it's overheating because the temperature light is on? If so, then it's possible that you have a bad temperature sensor and not an overheating engine.
Look for other signs of engine overheating :
1. Sluggish engine operation.
2. Detonation upon acceleration (pinging).
3. Rough, uneven engine idle.
4. Coolant boiling in overflow tank.
If your vehicle is experiencing these symptoms, then overheating is indicated. One of the most common cases of overheating is a bad thermostat. Another common problem is a faulty cooling fan or fan circuit. The cooling fan can be checked by running the engine at operating temperature and turning on the AC control. if the fan does not come on, then a problem with the fan circuit is indicated. The thermostat can be checked by placing a cooking thermometer on the motor near the upper radiator hose where it attaches to the motor. the temperature should not go above 225deg. If it does, then replace the thermostat. If the temperature stays at or below this rating, then replace the temperature sensor. I hope that this information helps you with your problem and thank you for using Fixya.com.

WARNING : Be very careful when working around cooling systems when the engine is at operating temperature. DO NOT open the radiator cap (if equipped) or even the overflow tank cap when the system is hot. Always wear safety glasses. Remember that electric cooling fans can operate at any time, even after the engine is off. Keep hands away from fan when working in the engine compartment.

on some of these models, the coolant temperature switch is close to the thermostat housing.

Take note of the blurb regarding NISSAN products below

A code P0128 may mean that one or more of the following has happened:

• Low engine coolant level
• Leaking or stuck open thermostat
• Faulty cooling fan (running too much)
• Faulty coolant temperature (ECT) sensor
• Faulty intake air temperature (IAT) sensor

Past experience indicates that the most likely solution is to replace the thermostat. However here are some suggestions on troubleshooting and repairing a P0128 OBD-II code:

• Verify coolant strength & level
• Verify proper cooling fan operation (check if it's running more than it should). Replace if necessary.
• Verify proper engine coolant temperature (ECT) sensor operation, replace if necessary.
• Verify proper intake air temperature (IAT) sensor operation, replace if necessary.
• If the above items check out good, replace the thermostat
• If Nissan vehicle, check for Technical Service Bulletins (TSBs), as the ECM may need to be reprogrammed to correct the P0128 code

Usually,when low temperature code is set,the thermostat is malfunctioning,although it could be a bad temperature sensor too.If the vehicle has alot of miles,and the thermostat is old,go ahead and replace it as it isn't very expensive,and a new one is good insurance against engine overheating as that can severely damage an engine.If the problem still persists,test or replace the temperature sensor,and check the wires and connector for a tight connection.Also check the entire cooling system for leaks or loose connections,weak hoses,and flush and fill with new coolant if old,as antifreeze deteriorates with age too.Good luck.