Temperature gauge does not go up but car is overheating

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

What make , model an year vehicle ?

Reasons the Temperature Gauge Reads High

If the temperature gauge reads high, it could mean your engine is overheating. Another reason your reading might be high is you could be losing coolant. A small leak or evaporation may cause your radiator to slowly lose coolant. A third reason your temperature gauge reads high could be because the thermostat is broken. If this is the case, you may need a coolant temperature switch replacement. The last reason the temperature gauge could read high is because of a water pump, or water pump gasket failure. If the water pump is malfunctioning, it may need to be replaced by a professional.

What to Do If Your Temperature Gauge is High

If your temperature gauge is reading high, it means your car is overheating. This is a very serious matter and you should never drive an overheating car. If your car starts to overheat, shut off the air conditioner and open the windows immediately. If this does not reduce the overheating, turn on the heater as high as it can go. If this still doesn't work, pull over on the side of the road, turn off the engine, open the hood carefully, and wait until the vehicle cools down. Never open the radiator cap while the engine is hot - coolant can spray and burn you. Once the vehicle has cooled, take the car to a mechanic right away so they can diagnose the problem. Cars are especially susceptible to overheating in hot climates, like what's common in cities like Los Angeles, Phoenix, Las Vegas, or Atlanta.
The temperature gauge is an important tool in your vehicle that shows the temperature of your engine's coolant. Contact YourMechanic and have your car inspected for overheating if it reads too high, as this can cause serious problems...

Reasons the Temperature Gauge Reads Cold

On most vehicles, the temperature gauge reads cold until the engine has run for a few minutes. If the temperature gauge still reads cold after the engine has warmed up, the gauge may simply be broken. Another reason the temperature gauge could read cold is if the thermostat in the vehicle stays open. With the thermostat stuck open, the engine can be overcooled, causing a low temperature reading. If this is the case, the thermostat may need to be replaced.

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 ....

Depending on the make/model/year/engine of your car, a "temperature sender", "temperature switch" or other sensor may be bad, or the wire from that sensing device to the gauge has broken. It's also possible that the gauge isn't getting power, or itself be broken.

Defective hose?

Good. Have a nice day. Did you have a question that needed an answer? Feel free to ask.

If your temperature gauge is reading too high, it can only be one of two things: The engine is overheating or the gauge is "lying" to you. I would recommend first taking the temperature of the cylinder head with an infrared thermometer to determine which one it is. If the engine is actually as hot as the guge says it is, then you need to check your cooling system. If the engine is not as hot as the gauge says it is then you need to diagnose and repair your gauge circuit. (most likely an inaccurate temperature sensor)

check the real value of the temperature sensor with a scan tool. Compare it withe the value in the gauge. It can be a defective temperature sensor or a damaged gauge...or else the car is really overheating

When your temperature gauge reaches "H' it may too late to prevent a major breakdown. Knowing the symptoms of an overheated car and how they occur may be the difference between being inconvenienced and incapacitated.
Identification:---Other than a low oil level or low oil pressure light, there is not a more significant part of a car's instrumentation than a rising temperature gauge or a glowing "Hot" light. These lights are really the only confirmation a driver has that his car is really overheating. It is the identification of the symptoms of an overheating car that enable the motorist to avert a badly damaged engine. Overheating is always a traumatic event for a car's engine, which makes the early identification of the symptom an important addition to the informed motorist's tool kit.
Stuck Thermostat:--The car's thermostat is a valve that controls coolant flow from the engine block to the radiator. When the engine is cold the thermostat remains closed so that the coolant can reach operating temperature quicker and also provide heat to the passenger's compartment. The thermostat has a spring on it that moves depending on coolant temperature causing the thermostat to open. Sometimes the thermostat fails to open thus restricting coolant flow to the radiator where it would be cooled down. This condition is often the cause of overheating. The symptoms of this cause would be a rising temperature gauge and possibly the loss of heat inside the car.
Restricted Radiator:---A car's radiator will have thousands of gallons of coolant passing through in its lifetime. Along with the coolant comes particulate matter in the form of corrosion breaking loose from various parts of the car's cooling system. These contaminates collect in the tubes of the radiator reducing its efficiency. Extensive "plugging" in the radiator will cause the car to overheat. The symptom of this condition would be a rising temperature gauge which goes up when you accelerate.
Coolant Loss:--A car's cooling system is a closed loop system. You are not supposed to lose coolant. Sufficient coolant loss will cause the engine to run hot because engine is heating less coolant to higher temperatures. The symptom of overheating induced by coolant loss would be a pool of coolant on the pavement when the leak is external. Steam under the hood as the lost coolant hits hot parts of the engine, or a rising temperature gauge in the case of a undetectable engine related leak. Of course, the gauge would also go up if the leaks were not detected. Deteriorated Water Pump:--Cars use a belt driven pump to push the water and coolant mixture through the cooling system. This part is called the water pump. Rarely the impeller that draws the coolant through the pump will rust away making it impossible to push any through the system. If this occurs the temperature gauge will climb and coolant will boil over in the radiator. Inoperable Fan:----Most cooling fans are electrically driven. Some are driven by fan belts. If a belt breaks or the electric supply to the fan is interrupted overheating may result. Electric fans are tuned on thermostatically when needed. When the car runs at idle for extended periods or the weather is extremely hot, a failed fan will cause overheating otherwise it serves as a standby assist to the rest of the cooling system. In stress conditions an inoperable fan will cause the temperature gauge to rise. This will help. Thanks please keep updated.please please do rate the solution positively .thank you for using fixya