V8 Twin SU Intake Manifold - Two Temperature Sensors?

[Burbling]

Hi

Apologies for a potentially bonehead question….

I am preparing a Rover P6 V8 intake manifold with twin SUs and whilst stripping it I have noticed that there are two coolant sensors fitted;

First one that screws in to the side of the thermostat housing by cylinder 2, in the book designated 'Coolant Temperature Sensor', this one I'll use for the gauge in the cabin.

Here's my question - the second sensor one on the top (with three small bolts) behind the thermostat housing, is designated 'Thermal Transmitter' in the Rimmers catalogue, but it's not showing up in any Haynes book I have on Rover V8s - can someone tell me what the sensor is for?

Don't think I need it, but better to check!

Thanks in advance.

[ChrisJC]

That is known as an 'Otter Switch'. Basically it it a temperature controlled switch. It closes at a pre-set temperature.

It is wired such that a light comes up on the dash when it is time to push the choke knob in!
It works in conjunction with a switch on the chock cable somewhere, so the light goes out when the knob is pushed fully home.

You can either fit it and not wire it in, or blank it off.

It means your manifold is from a manual choke vehicle.

Chris.