Why would an engine run cold temp gauge says cold and the heater blows slightly warm air?

The most common reason your temperature gauge staying on cold is a faulty coolant temperature sensor. It can also be caused by bad wirings between the cluster or the sensor. In some cases, it can also be a stuck thermostat causing the engine not to heat up properly.

1. What causes the temperature gauge to show cold when engine is hot?
2. Does coolant temp sensor affect heat?
3. Is it bad for an engine to run cold?
4. What causes an engine to run cold?
5. What sensor controls the temperature gauge?
6. What problems can a bad coolant temperature sensor cause?
7. What does a heater core temperature sensor do?
8. Is it bad to start your car and drive right away?
9. How do I know if my temperature sensor is working?
10. Can a temp sensor affect engine starting?

What causes the temperature gauge to show cold when engine is hot?

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.

Does coolant temp sensor affect heat?

Engine Overheating

If the coolant temperature sensor malfunctions, it could cause your car engine to get overheated. While sometimes a faulty sensor sends a permanent cold signal to the engine, it can also send a permanent hot signal.

Is it bad for an engine to run cold?

If you run your engine cold all the time, you'll most likely experience increased fuel consumption across the board. Additionally, you'll find higher amounts of carbon buildup at various parts of the engine. The most damaging effect of feeding a fuel-rich mixture to the engine is excess fuel reaching the exhaust.

What causes an engine to run cold?

The most common reasons for the temperature to remain low include: A thermostat stuck open. A bad engine coolant temperature sensor. A locked fan clutch.

What sensor controls the temperature gauge?

To troubleshoot your car's temperature gauge, you need to know how it works. The temperature gauge reading starts out as a reference voltage that is sent to the coolant temperature sensor. This sensor is nothing more than a thermistor -- a variable resistor that changes resistance with temperature changes.

What problems can a bad coolant temperature sensor cause?

If you notice that your engine overheats, the coolant temperature sensor could be the problem. At times, the coolant temperature switch may fail such that it starts transmitting hot signals permanently. This causes the computer to erroneously counterbalance the signal, thereby causing the engine to misfire or overheat.

What does a heater core temperature sensor do?

Designed for durability, electrical performance and provide the proper readings that are used in conjunction with the signals from the ambient air, sun load and cabin temperature sensors to control heater and fan operation.

Is it bad to start your car and drive right away?

Auto experts today say that you should warm up the car no more than 30 seconds before you start driving in winter. "The engine will warm up faster being driven," the EPA and DOE explain. Indeed, it is better to turn your engine off and start it again than to leave it idling.

How do I know if my temperature sensor is working?

Submerge your temperature sensor in the hot water and wait a few seconds to let your multimeter take a reading. Write down your reading so you can easily reference it. A hot water reading should give you around . 25 volts.

Can a temp sensor affect engine starting?

The sensor will not cause a no start. It could cause a hard start and a rich or lean condition only.