Morning All,

So I have an interesting problem. Basically, this mostly occurs only when restarting the Sport (MY2006 Supercharged) before it has fully cooled down. But it is now also happening on a cold start occasionally.

Basically, the temperature gauge will rapidly rise from cold, through normal to overheating in a matter of minutes. The cooling fan sounds like a turbine in overdrive whenever the engine is 'revved' but everything seems to work fine, no power loss, no error codes etc.

Now by driving over a speed bump, or two, the system will right itself. EG the temperature gauge will drop to normal within 2-3 minutes and the fan revert to normal operations.

This leads me to think that there's a sticking valve or sensor when the engine is hot that is causing this. Would this be right? If so which valve/ sensor could it be?

If not can you point me in the right direction (air bubble) as we're approaching summer here and the temperatures are already over 35°C so need to get this fixed.

Thanks in advance

Guy 2006 RRS S/C CONSTANTLY under modification...
1994 RRC 4.2l not LSE sadly gone but not forgotten
LR Defender 300Tdi - affectionately know as "The Black Beast"

Best guess would be a sticky thermostat? --
2010 Defender Puma 90 + BAS remap + Alive IC + Slickshift + Ashcroft ATB rear
2015 Range Rover Sport Supercharged V8 HSE Dynamic



Defender Puma Workshop Manual: https://bit.ly/2zZ1en9
Discovery 4 Workshop Manual: https://bit.ly/2zXrtKO
Range Rover/Sport L320/L322/L494 Workshop Manual: https://bit.ly/2zc58JQ

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Sounds plausible, if/when it happens again, see if the radiator hoses are hot or cold. Also, if you can get to your thermostat housing, try tapping it with something to see if that makes a change. 2019 5.0 SC SVA (Current)
2012 5.0 SC AB. Sadly written off by a campervan
23 plate Focus ST (Current)
1942 VEP Ford GPW Jeep (Willys) (Current)
1943 Whites M16 Halftrack (Current)
16 plate Eurofighter Typhoon, 2 x Eurojet engines with 20,000lbs thrust each. 1380mph

Thanks Guys, I'll look into that tomorrow.



Cheers

Guy 2006 RRS S/C CONSTANTLY under modification...
1994 RRC 4.2l not LSE sadly gone but not forgotten
LR Defender 300Tdi - affectionately know as "The Black Beast"