Hello

I am new to the forum so please bare with me.

I have an A4 and the temperature gage seems to go on and off (mostly off) It is funny that i realized when I washed the engine it made it come back on.
I am suspecting some bad connection. Does anyone know where the sensor would be located or where to look for a loose connection.
Incidentally the light bulb behind the light switch also seems to flicker and go off eventually.

Thanks

Ferenc ( Hungarian name )

 

I just changed mine on my 01 1.8T, very annoying place... but mine wasn't reading at all, either it's the sensor itself or the connection in your case i'm guessing it's the connection, (wires).

 

So where is this very annoying location for the sensor?

 

Which engine do you have?

 

Could be the sensor connection, locate the sensor, and do this

Disconnect the Engine Coolant Temperature (ECT) Sensor G62 electrical harness connector
Using a jumper wire , connect the Engine Coolant Temperature (ECT) Sensor G62 electrical harness connector terminals 1 to 2
Check the value indicated on the gauge display.
If the value jumps to approx. 140.0 ° C
End diagnosis and switch the ignition off.
Replace the Engine Coolant Temperature (ECT) Sensor G62 . Refer to Engine Mechanical, Repair Group 19.


Enjoy!

 

First of all thanks for the answers.

However my question remains where is this sensor G62 located.
I would need a photo or a description as I open the hood where to look.
I dont have a manual or repair book to look this up.

Thank you

 

if you have a 1.8T it is located right at the back of the cyl head against the firewall...

very painful to remove as it is very tight back there...

remove the crankcase breather (the black plastic pipe going out from the back of the cyl head) and it's right under it...

 

There are 2 coolant sensors. One located just infront of the firewall and the other IIRC is underneath the driver's side headlight. Here's a link to the one in front of the firewall:

audiworld.com/tech/eng.html. Look about 1/3 the way down, there is a DIY under this title:

Replacing the Engine Coolant Sensor
Article By: Victor Silva - 2004

(Sorry about the link but this site won't let me post urls unless I have 5 posts!!!)

My temp guage was fluctuating back and forth about 1 month back. Took a chance and replaced the firewall one and everything is fine now.

The sensor is about $36 at Audi or VW.

 

It's almost certainly the one at the back of the engine, which is famous for failing. Easy enough to replace: pull off the wire harness, slide the wire clip out of the way and tug it free. Be sure to replace the washer at the same time (comes with the sensor) - old washer sometimes doesn't come out with the old sensor and you have to fish it out.