Hi All,
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I've my MK1A for 10 years now
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& have changed the coolant a number of years ago with no issues.
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Yesterday I was driving to a show.
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Weather was very hot.
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After about 50 miles the temp gauge shot up into the red having been sitting in the middle for all the journey up to that.
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I quickly pulled over
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& switched off.
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Was driving at about 50mph at the time.
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Radiator did not feel very hot
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& coolant in the bottle was just above max.
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No fans running.
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I restarted the engine
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& slid heater to hot.
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Immediately the temp returned to normal.
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I drove on the last 10 miles to the show with the heater on
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& no issue.
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I tested turning off the heater
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& immediately the temp started to rise.
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For the journey home I put the rad fans
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& the engine bay fan running continuously
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& gauge sat just below the centre point.
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Engine temp didn't rise
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& weather was seriously hot
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& hot inside car with heater on.
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About 5 miles from home I turned off the heater
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& the temp gauge didn't budge.
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I've searched for this issue on the forum
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& it looks like it could be an airlock or possibly the thermostat,
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Anyone got any suggestions.
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Had trouble with a faulty gauge a few years ago but when this reacted when I put on the heater, it's probably OK.
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Tim