Thermostat and CTS?

[Nick101]

Hi guys, got the common temp and oil gauge don't move much untill idle where they go upto normal 90 degrees, but then drop when move off.

Is this just the thermostat? Or is the temp sensor faulty too? And will one or both of these cause the oil temp I not work correctly either?

Cheers!

 

[PAULF]

It'll most likely be the thermostat.

The oil is cooled by the engine coolant, so if the thermostat is stuck open the coolant flows through the radiator all the time and thus takes an age to heat. If the coolant is not hot, it will cool the oil too much. Once up to temp, the oil temp should roughly match coolant temp.

(at least you don't have 2.5 TDis like mine to change 'stats on!!)