engine cooling

[david jones]

where is the thermostat and how are the 2 cooling fans started.

[Simon Jones]

Thermostat in is a housing on the left side of the engine towards the front. It has a large pipe that goes to the radiator.

There are two temp sensors on the engine, both on the drivers side. The one at the front of the head (I believe) is for the temp gauge & the one lower down towards the back goes to the engine management which in turn controls the radiator fans.

In addition, there is a sensor by the handbrake that controls the scavenger fan mounted at front of the engine.

[dandywarhol]

............and they're all (except the thermostat ) controlled by the ECU.

[Grahame at work]

The ECU feeds 2 relays that are in the 2 banks of relays just in front of the main battery. I think in the rear bank - there is also a relay in that bank for the scavanger fan.

The ECU operates a relay to drive both fans at 'normal' speed when the coolant is just below 100C at the sensor and off when its dropped to below something like 85C. When (or if) the coolant reaches 107C it also operates the second relay and drives the fans at a higher speed.

regards Grahame

[The Great Pretender]

Also the air con works the fans.