Why is my temperature gauge going from hot to cold?

Why is my temperature gauge going from hot to cold?

Reasons the Temperature Gauge Reads Cold If the temperature gauge still reads cold after the engine has warmed up, the gauge may simply be broken. 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.

What would make my temperature gauge to fluctuate?

One common cause is a defective thermostat, a component that is inexpensive and easy to replace. Other causes of a fluctuating temperature gauge are a failing radiator fan, insufficient coolant level and a leaking cylinder head gasket. A failing radiator fan will be erratic.

Why is my car reading hot but not overheating?

If you find that you’ve got a car running hot but not overheating there might be a few reasons: Clogged or damaged radiator. Low coolant level. Damaged water pump or thermostat.

How do I know if my thermostat is stuck open?

Symptoms of a bad thermostat Thermostat stuck open: When the thermostat is stuck open, the engine temperature drops below normal when driving, especially on the highway in cold weather. A stuck-open thermostat can also cause lack of heat from the heating system. The Check Engine light may come on too.

Why does my temperature keep going up and down in my car?

The main reason why car temperature gauge goes up and down while driving is because something is not working properly in your car’s cooling system. It could be the radiator fan, water pump, thermostat valve, coolant, or the gauge itself. To fix either of these issues, we’d advise that you engage a proven auto mechanic.

Why does my temperature gauge read hot and cold?

If it reads approx. 140 Ohm (or more) when the engine is both cold and hot then the sensor is faulty and needs to be replaced. If the sensor reads 30-50 Ohms when the engine is hot then there may be a problem with the wiring back to the gauge or with the gauge itself.

What causes a car temperature gauge to stay on low?

What could cause the temperature gauge to stay on low? The most common causes of why the temperature gauge stays on cold are faulty coolant temp sensor, faulty temperature gauge, broken wires, bad thermostat , and air pockets in the cooling system.

What should I do if my temperature gauge reads 50 ohms?

If the sensor reads 30-50 Ohms when the engine is hot then there may be a problem with the wiring back to the gauge or with the gauge itself. Make sure the engine is turned OFF and that the vehicle’s ignition key is in your pocket when you test the sensor. Also don’t burn yourself on the engine block when the engine is hot Was this answer helpful?

What should I do if my temp gauge is not working?

Disconnect instrument cluster harness connector C237. Measure resistance between C237 pin No. 9 (Red/White wire) and pin No. 5 (Pink/Orange wire). If resistance is less than 5 ohms, repair/replace instrument cluster. If resistance is greater than 5 ohms, repair open Red/White or Pink/Orange wire.

Why does the temperature gauge stay on cold?

Air in the coolant system can also cause the temperature gauge to stay on cold if there is an air bubble right at the sensor spot. This can also often be indicated with a fluctuating coolant temperature gauge. If you suspect air in the coolant system, you have to bleed your coolant system with a unique technique.

Why does my temperature gauge read 30-50 ohms?

If the sensor reads 30-50 Ohms when the engine is hot then there may be a problem with the wiring back to the gauge or with the gauge itself. Make sure the engine is turned OFF and that the vehicle’s ignition key is in your pocket when you test the sensor.

What should the temperature gauge read when the engine is hot?

With a hot engine it should measure 30-50 Ohms. If it reads approx. 140 Ohm (or more) when the engine is both cold and hot then the sensor is faulty and needs to be replaced. If the sensor reads 30-50 Ohms when the engine is hot then there may be a problem with the wiring back to the gauge or with the gauge itself.

Can a temperature gauge be replaced on a car?

However, most temperature gauges are integrated with the instrument cluster on modern cars. In some cases, you can replace the temperature gauge or repair any bad solderings if you find any. In other clusters, you may have to replace the instrument cluster.