[Mk2] [NA] Temp gauge.

[BALDYMONSTER]

This problem with my temp gauge has come back.

The gauge seems to vary position randomly, sometimes fine for a day or two at halfway, other days sits at quarter and then halfway between quarter and halfway.

The needle doesn't jump around or fluctuate frequently it just seems to pick and choose where it wants to be from quarter to halfway.

No signs of leaks, thermostat was changed a couple of months ago, and recently topped up the expansion bottle twice which led me to think it had an airlock. Everything sitting where it should coolant wise and car never overheats and plenty hot air from the heating vents.

Any idea?

[Martin F]

I would like to rule out the gauge first, you can get nice digital aftermarket gauges for £50 off ebay, if that is changing then it is easier to see from where and to what.
If not then you know the gauge is the culprit.

As long as it isn't overheating I wouldn't be overly concerned. From what you describe is probably less than a 10 ndegree drop.
keep the heater on and see if it has the same continuous heat, take it from there...

[BALDYMONSTER]

Took the car out today and it sat two increments off the bottom all morning.

Took it out later and it climbed to halfway and stayed there perfectly.

Seems like an airlock perhaps?

[Martin F]

Took the car out today and it sat two increments off the bottom all morning.

Took it out later and it climbed to halfway and stayed there perfectly.

Seems like an airlock perhaps?

I don't think it's an air lock, as said, the sensor and gauge would be my first port of call, if you are not mechanically knowledgeable then best to stick it in a garage