coolant temperature gauge not working.


Registered User
Mar 20, 2012
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engine management light is on,changed the temperature sensor ,still not working.noticed the hot air is only warm.had a mate do a check with diagnostics and the temp gauge would flicker ?,strange ??.sometimes it goes up but not very often. any ideas ??,also noticed when idling sometimes the car is jumpy as if it is not running smoothly .
Jumpy idle could be your crankcase breather valve. 15 minutes to swap. If you try to remove your oil cap with the engine running and its held on by a vacuum (sucking in air) then you have a problem and this is likely it if no obvious split hoses.

Crankcase Breather Valve
035 103 245 G


[FONT='Segoe UI', Tahoma, Verdana, Arial, sans-serif]I just swapped out my temp sensor also because of an intermittent fault showing on VAG-com on the G62 sensor (it's two sensors in one). It's cheap but very hard to get to (right at the back of the engine by the firewall) and it will dump all your coolant when you take it out. Easy job in itself, just really really fiddly.[/FONT]

Could be just a faulty gauge, but with the lumpy running and the non-warm air through the vents, I'd be thinking thermostat.

They are not expensive, but a bit of a fiddle to fit. What were the diagnostic tests that your mate did? On Vag-Com/VCDS, the instrument check sends all the gauges through a full sweep, not just a flicker.
If you didn't have the heating problem too, then I'd suggest a faulty gauge.

The heating and lumpy idle could be unrelated of course.

You should be able to source a cluster of eBay and salvage the temp gauge from it. Worth a try, but otherwise thermostat is where I'd be looking.