Q: What's makes the temperature hand goes up then down?

asked by on

The temperature hand goes up to normal then goes to cold. The heater starts out warm then blows cold air.

My car has 150000 miles.
My car has a manual transmission.

If you are referring to the engine coolant temperature gauge on the instrument panel, unless the gauge is misreporting the temperature, a likely cause of too low of an engine temperature is a cooling system thermostat that is stuck in the full open position. If the thermostat is stuck open and the coolant is too low in temperature that would account for the inadequate heat in the cabin. There is also a heater control valve which you want to check and see if it is fully open, that is allowing hot engine coolant to enter the heater core (little radiator) in the passenger compartment. If you wish to schedule a heater is not working diagnostic please contact YourMechanic and they will dispatch a certified professional to assist you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. What's makes the temperature hand goes up then down?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: New thermostat and truck is still blowing only warm air. It blows cold air when idling

Trapped air in the cooling system can sometimes account for this but you are indicating that you are getting heat, at times, which would indicate that coolant is flowing. There is a heater control valve and you want to make...

Q: OBll CODE : P1899

Hi there. As the service manual reads, the resistance between pin 2 on the range switch and pin 6 black PCM connector must be checked for less than 5 ohms of resistance. Any more than 5 ohms of resistance and...

Q: Car switched off but did not start when I tried to restart

Hello. First of all, rotating the engine counterclockwise could very well cause the engine to "jump time", and cause engine damage. The timing chain tensioner is not designed for this pressure, and can allow the timing chain to jump one...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...