G60 Coolant System & Temp Gauge.

[shaun7086 0]

Hi guys ive just fully rebuild my g60 after it blew a piston now the bloody temprature gauge warning light is flashing 30secs after start up and stays on then the gauge goes up slowly to 100c fan has been bypassed onto manuel switch which i turn on to cool at 100c but then it doesnt go down it just stays at 100c ,Heater in car is blowing cold only goes warm when engine is reved at around 3000rpm. Ive replaced thermostat & water pump only thing i can think of its the coolant temprature switch, which switch is it the blue,or the black or both and if any of you guys have any ideas what could be causing this it would be greatly appreciated!

Thanks Shaun :?

[boost monkey 0]

did you change any of the sensors when you rebuilt the engine?

[shaun7086 0]

No m8 they all worked fine before so i thought they would still be ok!

[weetos 0]

Could it be head gasket gone and pressuring coolant system?

Go get a compression test done see if its down on 1 or more cylinders

[flusted 0]

Air lock? is it boiling over? black sensor is temp gaugecould always swap it for the blue 1 momenterally with just ignition on when it shows hot and see what happens on the gauge

[shaun7086 0]

Could it be head gasket gone and pressuring coolant system?

Go get a compression test done see if its down on 1 or more cylinders

 

i was thinking same thing but there is no oil in water and no water in the oil also no white smoke from exhaust!

[Supercharged 2]

If it flashes 30 secs after start up it must be a sender or level issue as it's won't have time to get that hot..

 

Air lock maybe causing the other issues too - it's not unusual for a car to run at 100c for a bit after engine work, should settle back down to 90 once te coolant has circulated a bit.

[shaun7086 0]

Fixed thanks guys it was a small blockage in the return pipe and the temp sensor was knackered :D