High Temp But Not Overheating

[DaveT]

The bad news - I was out and about at the weekend and experienced that heart stopping moment when you see the temp needle going into the red.
The good news - the AA man checked everything over using what looked like a laser gun and confirmed that all was ok. He suggested that it may be a dodgy sender unit. Drove the remaining 15 miles home without a problem but with needle still in red.

I have ordered a new unit, but is there anything else I should check?

Thank-you in advance for your advice! Dave

[Colonel Mustard]

Hi Dave,

The laser thingy is a temperature sensor, and they're very accurate. If the AA said the actual temp was okay...and tested several areas (not just the radiator) then it might just be a faulty sender unit. Do you run a thermostatically controlled electric cooling fan? If you have a kenlowe or something similar and the sensor for that wasn't keeping the fan running all the time then that would tend to confirm the fact that the engine wasn't actually overheating.

Also, have you lost coolant? If it has maintained coolant level, that's another positive sign.

Chris