Temp Sensor - Or Oil Stat Fault

Hi, can anyone help.

The temp gauge should stay at the half way point, if its floating around its a sign of the thermostat playing up. There are two on the tdci, the normal water thermostat and an oil cooler thermostat. its the oil cooler one that usually plays up.

The above is from another post but as usual there was no conclusion to the above post.

Can anyone confirm that the temp sensor needs changing or the oil coolant thermostat (if it even exists).

I fitted an EGR pipe which was split, in october, and as the weather has slowly got colder id noticed the temp gauge not going up when heter is on full heat setting..

Ive changed the main thermostat yesterday and my temp gauge is still at zero (moves up slightly when slightly hot even after 10 miles run. A good revv for a few mins makes the heat hotter). Since its turned cold. Heat is not mega hot like normal. Ive had the air con on all summer. The temp gauge should go up to the middle but only does so when i turn the heat dial to cold or when im towing a 1 ton trailer. (It conked out last week on way to Pboro so i put heat on full and arrived there then home later without further problems. - Temp was in middle while towing. As soon as i take trailer off and drive without it the temp goes back towards zero).

I think Ive been given the wrong temp gauge sensor, as i think the temp sensor is hidden behind top right pulley wheel. The gauge ive been sold is about 2 inchs with plug for the plug, not with a long wire to plug.

Mines getting towards 180.000miles on 02 plate.

2.0Ltr TDCI.

Help please if you have cured this fault.