S1 Au Falcon - temp guage fluctuating

[nartri]

hello there

got a problem with my folks car is that just today the car temp guage starts to fluctuate by which from normal (needle point at N) then goes to hot then goes back to N (from normal) and also the thermo fan would go to overdrive when it starts to move to the hot end of the guage and slow down when the needle goes to the lower end of normal

this happens mainly when i started to drive and stationary would stay at normal (low end)

i have already
- flushed the radiator
- check for fuses (not the relays dont know how too)
- replaced thermostat
- changed the coolant temperature sensor (located back of the engine)

from what i have read and told from machanics the problem is still there and have no idea why this is still going on

any help would be much appriciated

[JC]

Have you had the radiator and cooling system pressure tested, and properly flushed? Flushing with garden hose will not dislodge any built up gunk.

[nartri]

yeah im gonna get a pressure test tomorrow hopefully its something simple hahaha