Coolant Temp Sensor

**gavsman** · 24-05-2011,08:47 AM

Hi Guys, My Coolant Temp sensor is intermitant ( fluctuates between 50 & 90 when car has been running for a while) , can someone tell me where this is located in the engine bay? hopefully will be able to get a new one & fit it at the weekend.

**arman123** · 24-05-2011,09:35 AM

Ok if you remove your air filter housing stand in front of the car on the air filter side look down behind the bulkhead and you will see it at the bottom make sure you don't brake the clip when taking it off and make sure you take the old o ring out too just get a new clip and o ring when you buy the temp sensor one tip is you could tie a string to the clip incase you drop it at the back of the engine removing the clip is the only tricky thing

**Whiskylad** · 25-05-2011,01:36 PM

My temp gauge usually sits about 75ish goes up to high 80s then drops back again. Plenty hot air from the heater altho the gauge drops back to under 70 when the heater is switched on.
The radiator fan appears to spin all the time, is this normal?

Only getting low 40's mpg and suspect the extra cooling is causing this.

Thermostat, temp sensor, fan fault or combination of them?

**gavsman** · 25-05-2011,01:42 PM

Not sure - After I noticed my gauge fluctuating I plugged VCDS lite into mine & it shows a fault for the Coolant Temp Sensor.

**arman123** · 25-05-2011,03:17 PM

Most Likley a coolant temp sensor try changing it if it does not do the trick thermostat lazy and cooling engine that needs changing but first try coolant temp sensor easy and cheap

**Whiskylad** · 25-05-2011,03:39 PM

Does faulty temp sensor also effect mpg?

warp_speed · 25-05-2011,03:49 PM

Yes, because the car will change the amount of fuel used in the cylinders because it thinks the engine is cold and will add more fuel to the mixture to improve cold start. Your idling might be affected as well because the mixture is too rich. Had a friend who's 1.8 Golf GTI ran like a bag of spanners, a quick scan came up with the coolant sensor being duff. New sensor and all is well.