How to test Coolant Sensor?

[Muddy_fox]

Hello!

Can you help me on how to test the coolant sensor?

The one with "GREEN" connector.

I noticed that when my engine is cold my idle is around 1.3k rpm and it takes a while (10-20 mins) to drop to 850 rpm.

Thanks

 

[5e colin]

use a multimeter and trow the sensor in boiling water for 5 min then check the 2 pins again if it opens closes

 

[dac69er]

use a multimeter and trow the sensor in boiling water for 5 min then check the 2 pins again if it opens closes

its not a thermostat. the resistance will change depending on the temperature. not sure of the readings off the top of my head though. been covered a few times so may be able to find it with a search.

your idle sounds fine to me.

 

[Muddy_fox]

its not a thermostat. the resistance will change depending on the temperature. not sure of the readings off the top of my head though. been covered a few times so may be able to find it with a search.

your idle sounds fine to me.

I find this Water-temp-sensors-what-are-the-symptoms-if-failed but there's no guide or instruction on how to test the sensor. Also you've mentioned that the resistance change as the temperature change, do you have a resistance value for diff temps?

thanks

 

[dac69er]

as i said, i cant remember them. havnt tested one in a long time.

if your not getting a coolant temperature sensor error code i wouldnt worry as your idle seems normal to me. if your coolant sensor is gone you will get consistantly strange idle and it will run badly.

 

[weeJohn]

At 80 degrees Centigrade it should have a resistance of 322 Ohms, the colder the coolant is, the higher the resistance goes, about 10KOhms for 10 degrees from memory.