V40 Cooling Fan Running on

[rthackery]

Cooling fan intermittantly runs on after switching off engine, even after a short run in this weather = i.e. when engine still cold. Any ideas welcome please

[mharriso]

temp sensor may be knackered, signalling hot all the time.
does the car run a little rough also, if yes may reinforce the above.

[ricky.n]

probably the fan relay in the box under the bonnet . this happened to me overnight and flattened my battery but the potential for a fire shouldnt be overlooked

[rthackery]

Originally Posted by mharriso

temp sensor may be knackered, signalling hot all the time.
does the car run a little rough also, if yes may reinforce the above.

Thanks - worth a try. However, it runs perfectly otherwise. Also doesn't run on every time I switch off.
Where do I find the temp sensor, is there any way of testing it?

[rthackery]

Thanks, will look at that. It always seems to stop after a few minutes though.

[McSquire21]

As you open the hood of the vehicle facing the car (obviously), the temperature sensor is to the left of the 4th Exhaust Pipe. Directly next to the left exhaust pipe, there is a water coolant hose, coupled to the thermostat housing by an "expanding metal ring" adjusted by a screw driver.

You will need to take off the Engine Plastic Covering which will allow access to the water hose.

You will need to take off this water hose and access the Theemostat housing. you will then remove the head of the thermostat housing with a T40 torx (the same type used to take off the plastic covering).

Right there looking at you will be the ECT sensor and thermostat. The sensor is not strongly coupled to the housing so an adjustable wrench will take it off. Just pull out the thermostat.

both should cost around £40 from dealers or go to:

http://www.partsforvolvosonline.com/...oducts_id=5048

and order parts online for cheaper.

McSquire

[rthackery]

Just to post the eventual solution - which may help others. On investigation, one of the wires to the connector on the temp sensor appeared to have nipped off right inside the connector. Quite why this should have happened is a mystery. The only thing I can think of is that the problem started very soon after a main dealer service! - Maybe the mechanic was a bit hamfisted if he was in that area(?!) However, reconnecting and soldering the wire all is now ok.