Coolant temperature sensor

anbran · Post by **anbran** » 28 Feb 2008, 16:24

How do I test to see if my coolant temp. sensor is working properly?

I've also checked out the thermostat and it opens in boiling water and closes in cooler water...Does that mean that its ok?? I believe its the original one (It has Volvo on it and is made in Germany.)

1998 V70 non-turbo 188, 000 km

Post by **MadeInJapan** » 28 Feb 2008, 17:07

If your thermostat checks out but still your temperature gauge is not at 3:00 when your car is warmed up your temp. sensor is shot 99% of the time. If you really want to make sure, you should have your codes read and you should get a P0116 for a signal fault, P0117 for temp. too high or P0118 for temp. too low. Hope this helps.

Post by **Ozark Lee** » 28 Feb 2008, 17:16

The boiling water test is generally accruate but it should open before the water boils. There are two versions, one opens at 87

Adler · Post by **Adler** » 28 Feb 2008, 21:29

I've noticed that my the needle on my temp gauge sits at 4 o'clock most of the time, rarely reaching 3 o'clock. Is that an indication the thermostat is finished? The car is a 1998 S70 non turbo with 136k miles

Post by **lewismug** » 28 Feb 2008, 21:42

Yes, that means your thermostat needs to be replaced. Replaced mine a few weeks ago. It was doing the exact same thing.

sony2000 · Post by **sony2000** » 29 Feb 2008, 06:54

Anbran, if you are there (thermostat), change it. They have a limited life and are relatively cheap.

porsche1977 · Post by **porsche1977** » 03 Mar 2008, 17:28

MadeInJapan wrote:If your thermostat checks out but still your temperature gauge is not at 3:00 when your car is warmed up your temp. sensor is shot 99% of the time. If you really want to make sure, you should have your codes read and you should get a P0116 for a signal fault, P0117 for temp. too high or P0118 for temp. too low. Hope this helps.

Hey i have a code P0116 what do i do for a signal fault? Car seems to be running fine temp is at 3:00.

Post by **MadeInJapan** » 03 Mar 2008, 17:51

Check the wiring and the connector. If the wires aren't the problem, pull the connector loose and spray some contact cleaner in both ends and push it in and out a couple of times to make sure and clean the contacts. Even if you're getting a signal at your instrument panel, the ECU might not be getting the correct signal to turn on your radiator fan and also adjust your air/gas mixture. If all of the above still doesn't get it then even if everything seems to be checking out fine, your best off replacing the sensor. Especially when the weather warms up it will be crucial that your fan turns on to help keep your radiator and thus your engine cooled. Hope this helps.

porsche1977 · Post by **porsche1977** » 04 Mar 2008, 07:46

MadeInJapan wrote:Check the wiring and the connector. If the wires aren't the problem, pull the connector loose and spray some contact cleaner in both ends and push it in and out a couple of times to make sure and clean the contacts. Even if you're getting a signal at your instrument panel, the ECU might not be getting the correct signal to turn on your radiator fan and also adjust your air/gas mixture. If all of the above still doesn't get it then even if everything seems to be checking out fine, your best off replacing the sensor. Especially when the weather warms up it will be crucial that your fan turns on to help keep your radiator and thus your engine cooled. Hope this helps.

Thank you, i'll give it a try!

porsche1977 · Post by **porsche1977** » 04 Mar 2008, 16:26

porsche1977 wrote:
MadeInJapan wrote:Check the wiring and the connector. If the wires aren't the problem, pull the connector loose and spray some contact cleaner in both ends and push it in and out a couple of times to make sure and clean the contacts. Even if you're getting a signal at your instrument panel, the ECU might not be getting the correct signal to turn on your radiator fan and also adjust your air/gas mixture. If all of the above still doesn't get it then even if everything seems to be checking out fine, your best off replacing the sensor. Especially when the weather warms up it will be crucial that your fan turns on to help keep your radiator and thus your engine cooled. Hope this helps.
Thank you, i'll give it a try!

Oh one other thing where is the sensor? thanks again.