Q: Do I have a bad coolant temperature switch?

asked by on

My temperature gauge is reading hot almost immediately after I start to run the car. The coolant is full, and I just replaced the thermastat. Is there anything else that my be causing the problem?

My car has 138000 miles.
My car has an automatic transmission.

In order to verify that the coolant sensor’s output reading is correct, you will need to have the engine computer system scanned and look at the data before the engine is even started. The temperature of the coolant sensor and the ambient temperature sensor should be the same or very close to each other.

If the coolant temperature sensor is not reading very close to ambient temperature within a few degrees, then replace the sensor. Make sure all air is bled out of the cooling system and recheck the temperature as it warms up to make sure temperature reads normal.

I recommend having a certified mechanic, such as one from YourMechanic, inspect the car and determine why the temperature gauge is reading hot.

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. Do I have a bad coolant temperature switch?

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: My brother-in-law is fixing the car. First time yes it's been going on about two weeks finally the check engine light came on yesterday.

If the spark plugs are becoming coated with engine oil and there is excessive oil in the exhaust system, then there could be three symptoms to check. Symptoms PCV Valve could be plugged making the engine over pressurize and...

Q: inaccurate odemeter.. time and gear indicator not showing up on dashboard

It is possible that your alternator could be going bad as this is a common symptom of alternator failure. I would recommend having the alternator tested and replaced in order to resolve this issue. Consider YourMechanic as alternators can be...

Q: Coolant depletes quickly

The temperature gauge issues may be the result of a faulty coolant temperature sensor or a low coolant level. If there is no coolant in the system, the sensor cannot read temperature accurately. It would be best to consult the...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...