Audi A4 B6 (2001 - 2005) - 01 2.0 Heater and temp gauge problems

Honest John Back Room » Technical matters
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Sat 13 Dec 2008 11:11
01 2.0 Heater and temp gauge problems - andyjarv
I have recently had a new thermostat fitted on my 2.0ltr 20v B6. At first the heater worked great and the temp gauge read constant 90 deg which is correct for this model, however now I am having a few issues which I need help with as I have a couple of long journeys ahead.

1) The heater only produces lukewarm air until the gauge has reached 90 deg and even when at that temp it doesn't blow that warm it only really blows hot when driving at 50mph plus. The heater temp seems to drop during town driving.

2) Occasionally the temp gauge drops down to cold and stays there for a period of time before returning to correct reading, the heater temp stays constant and blows hot.

I have no warnings coming on ie engine management and levels check ok, the thermostat is a complete unit incorporating the relevant sensors for temp gauge and engine management.

I have tried the heater unit in different mods ie AC, Econ, recirculate etc all set with temp on High and the heater motor set at about 50%, the problem is still there. The car runs perfectly well and the only thing missing from the system is the pollen filter which the garage removed because it was goosed, haven't got round to getting a new one, but can't see this being the problem.

Edited by Webmaster on 13/12/2008 at 12:32

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Thu 18 Dec 2008 11:33
01 2.0 Heater and temp gauge problems - piston power
Its not unusual for a new thermostat to be faulty and stick open.

Do the engine hoses get hot? and the heater hoses?

May be just a simple bleed any trapped air that has got into the system.

As for the gauge readings this seem like the sensor may be faulty, take this back to the garage.
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Fri 19 Dec 2008 18:34
01 2.0 Heater and temp gauge problems - andyjarv
The hoses get warm and the heater seems to work ok now, still got an intermitat temp guage though, the unit fitted was agenuine VAG part and comes with sensors.
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