So when i did a trackday a while back i had the car try and overheat, which i put down to an air pocket in the coolant system as it was fine on road before and after.
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However, its now overheating on road, and very quickly!
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First issue is fan.
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.
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.
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.they don't appear to come on at all, however i pulled the plug off the rad temp sensor and they came on.
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It still overheats with them running all the time, so that's not the cause of the overheating, but is obv not right.
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I took the sensor out and did the test where you boil it in a pan of water and check resistance at various temps.
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.
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.
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.
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.all was correct, so don't think that's the cause of no fans.
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Whats next most likely thing to cause the fans not to come on?
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As for the overheating.
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.
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.
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.engines runs fine, no leaking from any bit of the cooling system is obvious
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(tiny small leak out rad, but not to level of losing about 6 litres of coolant i keep having to put in the car!).
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Pipes appear same temp coming out of and in of radiator when car is warm.
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Could thermostat be the cause
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(seems to work as when warm coolant colour changes
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- i'm only putting in straight water at this point
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- suggesting to me its
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'releasing' coolant into the engine).
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I'm just trying to work out if i haven't thought of anything easy to check, before i get a block leak test kit to confirm its the headgasket
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(compression leaking into coolant)!
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Suppose other thing is water pump.
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.
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.
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.is it possible for one to stop pumping coolant around engine? Or would that be obvious?