WATER TEMP AND OIL GAUGE NOT WORKING - A6

[A6 trouble]

Hi All,

Both my Water temp and Oil gauge are not working on the instrument panel of my Audi A6 (2001). They both packed up together although under long journeys (with temperature) they show a small sign of registering low readings.

I have read many forums that indicate the Instrument Panel may need replacing but would this be the case if two gauges went at the same time?

Many thanks

[onzarob]

Hi, I've moved your post to the correct area, should get a better response here;)

On the subject the instrument panel, they can be tempramental on most of the VW audi range. But there are other causes.

The best plan first would be to get the fault codes read for the instrument cluster as this would help allot.

The Water temperature sender is very tempermental, but i don't ever recall seeing a complaint about the oil gauge. the fuel one does play up more.

There are a few companies who refurb the cluster, or you can get one from the dealer, but I've seen quotes for £400+

Let us know how you get on.

Rob:D

[A6 trouble]

Many thanks Rob,

I was hoping and preying for a quick cheap fix. Looks like a main dealer may be my only option.:(

Regards

[ambax62]

Hi I also have an A6 2.0 SE (2001) that has suffered similar fate in the last week. Neither the oil or coolant temp gauges are working. The coolant gauge will move with some speedy driving but still does not reach 'normal working' mark.

Was wondering if you had managed to resolve your problem?

[ambax62]

Hi again. It appearsyour problem might be with the thermostat apparently this is not uncommon with 2000/2002 year A6's. I took mine to an independent VW Audi garage in Dorking who were extremely helpful and a darn site cheaper than main dealer!..still cost £280. They replaced both the thermostat, housing and sensor. Since then both guages are working fine. Hope this helps

[Zulu]

Hi,
I've just seen this thread, having posted a similar question about Oil/Water gauges on my 1997 A4.

Did you have any luck?

cheers, Zulu.

[ambax62]

Hi Took to independent Audi garage Tutts in Dorking. Transpired it was something to with the thermostat and temp sensor. Cost me about £200 to have it repaired. Andy

[Zulu]

Hi,
I've just seen this thread, having posted a similar question about Oil/Water gauges on my 1997 A4.

Did you have any luck?

cheers, Zulu

[rayseakayak]

Hi,
I have recently purchased an AUDI 2.5 TDI SE AVANT year 2001,
I noted the coolant temperature was very low, around 60~70°C, the temperature does increase when travelling at higher speeds on the motorway, this would indicate that the element is faulty. Does anyone know where the thermostat is located, it is certainly not visible from the top of the engine so I assume it is somewhere under it. Running at too low a temperature is liable to increase cylinder wear rates so I need to replace the element asap, any help would be gratefully received.

Rayseakayak

[onzarob]

Hi,
I have recently purchased an AUDI 2.5 TDI SE AVANT year 2001,
I noted the coolant temperature was very low, around 60~70°C, the temperature does increase when travelling at higher speeds on the motorway, this would indicate that the element is faulty. Does anyone know where the thermostat is located, it is certainly not visible from the top of the engine so I assume it is somewhere under it. Running at too low a temperature is liable to increase cylinder wear rates so I need to replace the element asap, any help would be gratefully received.

Rayseakayak

Hi, your temperature reading could be one of many thing including the thermostat, but not thermostat common problem for poor temp readings. the temp sender is a common faulty part, also the water pump has a habit of failing as well. the impeller is plastic and detaches from the spindle ;)

I would get a code scan done first to rule out the sender then go form there. :)

[Peter D]

I need the engine code. PM me with you email address and I'll send you the drawing. It is probably sticking out of the top of a pipe under the cover on the left hand side of the engine ( from the front)
Coolant temperature in °C Resistance in Ω 60 approx. 259 90Ω approx. 107Ω 120 approx. 40Ω

Regards Peter

[varadero]

Hi . I have had similar problems with my 02 model still not resolved despite considerable expense.

So far I have had the water temp sensor replaced , system flushed and the sensor for the cooling fan replaced. Neither the water temp nor oil temp gauges work and heating is cool at best. Engine runs fine .

It seems there is an inclination to replace everything in the hope of finding the problem, I stopped them replacing the oil temp gauge.

My cooling fan is always on even in -5 C but nobody can sort it out, going to an auto electrician seems to be my only hope. I will post an update when I can.

[audi67]

Hi. It's interesting the water and oil temp gauges can be temperamental. My 2003 A6 1.8t has duff fuel and voltage gauges. Being an Audi I suspect the answer's "no" but is there an inexpensive fix for these problems?

[kite]

Hi . I have had similar problems with my 02 model still not resolved despite considerable expense.

So far I have had the water temp sensor replaced , system flushed and the sensor for the cooling fan replaced. Neither the water temp nor oil temp gauges work and heating is cool at best. Engine runs fine .

It seems there is an inclination to replace everything in the hope of finding the problem, I stopped them replacing the oil temp gauge.

My cooling fan is always on even in -5 C but nobody can sort it out, going to an auto electrician seems to be my only hope. I will post an update when I can.

If you turn the aircon off does the fan still run...

[varadero]

In my case the garages (Audi specialists ) seem to take the easiest route of replacing things rather than fixing the problem. I believe that the gauges and sensors are/were fine, neither of two garages noticed that the coolant fan runs all the time so the engine doesn't get hot enough and neither knew why it was running or how to stop it hence the auto electrician.

Learning point is don't trust engine management system diagnostics and treat the gauge as innocent until proven guilty

[ambax62]

Have you had the thermostat itself replaced? I had this done when both my water and oil temp gauges failed. The problem was then cured. If it helps I used Tutts of Dorking, Surrey and independent VW Audi Garage

[ambax62]

Not sure if this will necessarily help. But may be worth checking if you have any water in passenger footwell. It is known problem with A6 that gulley above bulkhead can retain water which can then get into cabin. Then Main ECU is under carpet in passenger footwell and could cause sensors to become temperamental. If there is damp then having dried out carpet and underneath (be aware that can take some time and people have suggested using dehumidifier) then disconnect battery for at least 30 mins this should cause the main ECU to reset itself and hopefully problem gone. In any event even if there is no damp suggest disconnecting battery as described. It might just work.

[varadero]

Thanks for the thought. The garage said the stat was ok as the bottom hose was heating up and when they fail they fail shut so I should be boiling over. With 92k on the clock I can't complain but I have spent £200 so far and i am reluctant to spend another £250 if the problem is elsewhere. It does seem odd that both gauges stopped working at the same time though. I started it this morning in the freezing cold and the cooling fan came on straight away which is very odd. I will see what the auto electrician says and if he doesn't know change the stat.

[kite]

Thanks for the thought. The garage said the stat was ok as the bottom hose was heating up and when they fail they fail shut so I should be boiling over. With 92k on the clock I can't complain but I have spent £200 so far and i am reluctant to spend another £250 if the problem is elsewhere. It does seem odd that both gauges stopped working at the same time though. I started it this morning in the freezing cold and the cooling fan came on straight away which is very odd. I will see what the auto electrician says and if he doesn't know change the stat.
The fan will run if the aircon is on.....

[varadero]

Not sure if this will necessarily help. But may be worth checking if you have any water in passenger footwell. It is known problem with A6 that gulley above bulkhead can retain water which can then get into cabin. Then Main ECU is under carpet in passenger footwell and could cause sensors to become temperamental. If there is damp then having dried out carpet and underneath (be aware that can take some time and people have suggested using dehumidifier) then disconnect battery for at least 30 mins this should cause the main ECU to reset itself and hopefully problem gone. In any event even if there is no damp suggest disconnecting battery as described. It might just work.

Thanks Ambax62 I will have a look

[varadero]

If you turn the aircon off does the fan still run...

Yes it does. It gets hot enough to switch the choke off but it takes 15 minutes to put out any heat into the car,radiator coolant fan never stops. If you shield the radiator grill water temp gauge rises by 10 C but heating is still low

[ambax62]

Not sure about the advice you received. Both my gauges failed at same time too...but definitely no overheating. I was surprised too when the garage had to change the stat but can confirm success. The total cost was about £230 parts and labour

[varadero]

Not sure about the advice you received. Both my gauges failed at same time too...but definitely no overheating. I was surprised too when the garage had to change the stat but can confirm success. The total cost was about £230 parts and labour

Many thanks , there doesn't seem to be any water/ dampness in the passenger well the electrician wants £50 just to look at it so I will bite the bullet and have the stat changed instead, here's hoping !!!

[mickmcvw]

The garage said the stat was ok as the bottom hose was heating up and when they fail they fail shut so I should be boiling over.

Not always the case. My '02 2.5TDI is in the garage today having the thermostat changed along with a full timing belt service. The thermostat is most certainly stuck open as both water and oil temperature guages are way below where they should be. The water temp should always sit at 90c as the thermostat is preset to open at 89c...

[allan_audi]

Not always the case. My '02 2.5TDI is in the garage today having the thermostat changed along with a full timing belt service. The thermostat is most certainly stuck open as both water and oil temperature guages are way below where they should be. The water temp should always sit at 90c as the thermostat is preset to open at 89c...

Did anybody get to the bottom of this. I have just changed my thermostat because of low oil and water temp, only to find when I put back together and started that the electric radiator fan was running constantly. I disconnected for now and bingo runs at 90Deg coolant temp. I can't find any info on the fan control unit at all, I don't even know where it is. If I disconnect the thermo switches the fan still carried on running.

[bagpipingandy]

Did anybody get to the bottom of this. I have just changed my thermostat because of low oil and water temp, only to find when I put back together and started that the electric radiator fan was running constantly. I disconnected for now and bingo runs at 90Deg coolant temp. I can't find any info on the fan control unit at all, I don't even know where it is. If I disconnect the thermo switches the fan still carried on running.


Did you try running the car with new thermostat in and the fan left wired up?

I Believe the fan runs for the air con, if you switch air con off the fan will also shut down.

[mickmcvw]

Thermostat replacement fixed my problems anyway. Water temp sits happily up in the centre and oil temp is nicely higher than before. Could all be in my head but I think it's driving much better too...

[allan_audi]

Did you try running the car with new thermostat in and the fan left wired up?

I Believe the fan runs for the air con, if you switch air con off the fan will also shut down.

I ran the car for half hour or so, at Idle and at periods of 2000-2500RPM with no movement on the gauge. The radiator was cold with the top hose only warm say 40-45Deg. As soon as I disconnected the fan the temp started to climb and was at 90Deg in 10 mins or so. I will try and run the car on the road with the fan re-connected though just to see. Seemed odd, why would the fan be on even when the coolant and/or ambient air is cold.

[bagpipingandy]

I ran the car for half hour or so, at Idle and at periods of 2000-2500RPM with no movement on the gauge. The radiator was cold with the top hose only warm say 40-45Deg. As soon as I disconnected the fan the temp started to climb and was at 90Deg in 10 mins or so. I will try and run the car on the road with the fan re-connected though just to see. Seemed odd, why would the fan be on even when the coolant and/or ambient air is cold.

My A4 was the same I thought the fan was cooling the engine in error, but I was told it is running for the air con, (thin radiator in front of main one) don't know exaclty why but it just does. when ever i switched off heating/air con system the fan would stop.
The fan runs from start up cold engine. (confused me!!) but a new thermostat fixed engine running cool.

reconnect fan and see what happens, the running cool to start may have been air in the system.

Andy

[allan_audi]

Hmmm, just re-connected the fan for journey home and all is still fine (thanks Andy for the advice), sits at 90Deg, seems electric fan should be on. The thermostat was the problem after all.

Strange that the old thermostat seemed to work ok when I tested it. I wonder if there's some other issue when they're in situe, ie. when there's water pressure on them from the pump.

[bagpipingandy]

Hmmm, just re-connected the fan for journey home and all is still fine (thanks Andy for the advice), sits at 90Deg, seems electric fan should be on. The thermostat was the problem after all.

Strange that the old thermostat seemed to work ok when I tested it. I wonder if there's some other issue when they're in situe, ie. when there's water pressure on them from the pump.


I think the problem is mentioned somewhere in this thread, which is they open too early when faulty, not so much stick open. hence you cannot see it unless you heat it gradually.

great its fixed. seems a lot of us 2.5 owners have the running cool issue, I've still to change mine!! get to it one day....

Andy

[varadero]

Replaced thermostat and both gauges working as they should , running at 90 deg plus petrol consumption improved.:D