Car Temperature going up & down while driving.

[RandyMarshx]

Have a vy ute v6 series 1.

Doesn't just happened when i stop or slow down, it can happen when im driving at 100km, it will overheat for about 15 second then cools down.
Originally thought it was the thermostat, which I replaced & did a coolant flush/replace.
For 5 days I thought it was fixed, but now its happening again and far more frequent.

Any one know what it can be? or any tests I can do.
thanks.

 

[skappascrap]

Did you bleed the cooling system once you flushed and replaced the coolant?

 

[RandyMarshx]

Did you bleed the cooling system once you flushed and replaced the coolant?

Uh not sure if its bleeding but I had the car in an upright position, with the car running & radiator cap off?

 

[Anthony123]

Warm the car up then the screw on thermostat housing undo until coolant is constantly spraying out the bleed hole the close up and done, if problem is still there replace coolant temp sensor

 

[lowandslow]

Yep. Sounds like air in the system.
Have your heater cranked and unplug your thermo fans to speed the process up.

 

[RandyMarshx]

I did that last night, It could also be a water leak, i saw water dripping from the right hand side (facing the car) of the radiator today, was busy at work so didn't have time to give a closer look.
If this was the case, the temp wouldnt be going back down would it?

 

[RandyMarshx]

I have a leak and i looked under and seen this hose pretty munted, Although the day before the leak was on the other side..
Would you think this hose is the problem?
(taken from the right front wheel)
P.s I'm a noob at cars.