[boardshortsben]

Hi there,
Own a 2000 Renault Master 2.8dTi. Have been trying now for a few weeks to work out why the Coolant Temperature Warning Light comes on after I start driving. The temperature gauge rises to a 1/4 - doesn't sit in the middle and for a while everything is fine and no light comes on. After around 10 minutes of driving the Coolant Temperature Warning Light comes on and stays lit red for the duration of the journey. I have stopped stopping to check if the engine is overheating (doesn't seem to be).

So far I have drained the coolant, checked to see if the thermostat is working fine (put in boiling water - seemed to open okay), replaced the temperature sensor, re-filled coolant with bleed screw open to avoid air bubbles etc.

Does seem to be a fair bit of oil all over the connectors and thermostat housing.

What could be causing the light to come on?

Thanks

Ben

 

[Brendan W]

In general the light comes on because the ecu sees something unexpected from the general direction of the temperature sensor.
This could be a break in the wiring to the sensor or trouble at the plug. Does the fan come on?

 

[boardshortsben]

In general the light comes on because the ecu sees something unexpected from the general direction of the temperature sensor.
This could be a break in the wiring to the sensor or trouble at the plug. Does the fan come on?

interesting, it had radiator changed this year - maybe I need to re-set the eco?

Not sure if fan is engaged or not - would need to check.

 

[Brendan W]

Shouldn't need to reset the ecu for a rad change.
There could be some air still trapped in the system and that will cause the temperature sensor to under read if it's in an air pocket.
Generally if the ecu loses sight of the sensor either by a break in the wire or deliberate disconnection it will tend to put the fan on as a precaution. Not overly familiar with that engine though.
With everything ok the needle should stay in the middle plus or minus a needle width.

 

[boardshortsben]

Shouldn't need to reset the ecu for a rad change.
There could be some air still trapped in the system and that will cause the temperature sensor to under read if it's in an air pocket.
Generally if the ecu loses sight of the sensor either by a break in the wire or deliberate disconnection it will tend to put the fan on as a precaution. Not overly familiar with that engine though.
With everything ok the needle should stay in the middle plus or minus a needle width.

Will have a look any wires and test connectivity. Needle never gets to the middle which is odd - maybe that's the fan kicking in and preventing it from getting warm?

 

[Brendan W]

Fan should only kick in if the needle goes above the normal position or there is no signal at all from the sensor.