Originally Posted by Colin RedGriff View Post
Is the low speed fan working correctly? If you can hear the fan when driving the this may be the high speed fan which means the car is near to overheating.
There is a large resistor which controls the low speed fan operation but it's not uncommon for this to burn out and stop the low speed fan operating.
There is a massive thread on northamericanmotoring.com titled "low speed fan we need a fix" unfortunately I'm not able to post links yet.
The gauge in the car is controlled by the ecu and NLT tracks the temperature up to the normal temp. It does not show the actual temperature even if the car gets hotter. It will eventually rapidly rise up to the red sector but it is no use as a guide to show if the engine is running a bit hot.
You can get the actual temp to show on the speedo whe you turn on by entering the diagnostic menu which might be worth doing to see what is actually happening.
Thank you, this has been a great help. The temperature dial doesnt seem to go above the middle even when the reservoir is boiling up. So i will definitely have a look on how to get the true temperature up in the diagnostics menu.
I dont believe i have fixed it. After changing the temperature sensor, the problem still occurred.
I have a feeling it is the head gasket. The BLOCK test showed no carbon emissions in the cooling fluid however, so its a real mystery at the moment.
You can also see the bubbles coming up in the coolant when you take the cap off (air bubbles bubbling up a little) which makes me think its the head gasket.
After fitting the new temp sensor, i raced it round the block putting load on the engine, and then reved it on the drive, sure enough it erupted. It hasnt happened since though, but i have done smaller journeys worth about 90miles, which is promising, but i still feel like the problem is there because it cant just go away. Perhaps the smaller journeys allow the pressure to be relieved before the next one.
Is the smaller fan for the power steering fluid? I dont notice the fan when driving, its usually when ive stopped at a light it will come on and off. The engine does 'hunt' on startup.
My father is an ex-mechanic, so I will query him about it too.
Its a shame my mechanical engineering degree doesnt cover general mechanics, i think it definitely should.