Gauge Temp Sender - showing overheat again - any suggestions? yes I know...its been done a lot

[blanes]

Apologies as this has been done to death, but still no luck on this 1.3 engine.

Symptoms.

Drove 30 miles, no probs.
Started next day from cold, temp guage slowly went into red after about 2 minutes and stayed.
So, unscrewed old one and replaced guage temp sender with brand new one.
It worked then, car temp levelled out at mid temp of gauge and fan kicked in when hot, hooray, fixed...so i thought.
Then, 2 days later started car up again, with new sender in, its started to go off the gauge again.
Surely a brand new temp sender wouldn't fail straight away would it?
Putting Wire against head flicks gauge up to red, take wire off and guage is down to cold.
Ive tried banging the guage cluster for loose wires but no change, still in red.
I tought it might be thermostat but heater vents are nice and hot
I'm wondering where to go next with it, and annoying cos I just wanna drive the thing.

All help appreciated as ever, Blanes

 

[h701micra]

I had a similar problem on another car the other dat. Turned out that the rad just needed bleeding properly. Did change the thermostat for good measure.
Taking the wire off will send it to cold as there's no signal. And putting it on the head earths it completely.
(A temp sensor is pretty much a variable resistor so it varies voltage sent to the gauge varying the temp you see)

 

[r-reg-sr]

had a broken sensor do this on a previous k11 (yes i fall for the same thing again and again)

if your heaters are normal i think your new sensors given up,,go exchange it

 

[blanes]

Cheers, will give it another go, what a pain in the arsch.