Water Gauge not working - Page 2

Crossle · 26-09-16, 12:26 PM

I am not sure what make it was to be honest, just got it from GSF car parts but on the odd occasion it did read with the old sender it always used to shoot up to 3/4 even if the engine had not been started and was stone cold- seems to e its very spot regardless of the sender I've had in it.

Randomly today after initial flicking around for the first few miles it settled at just below half and stayed there which is probably a realistic reading. I think its the first time its done that on the last few months. Not really sure where to go with it now, think maybe I will have to get an Auto Electrician up as it would seem its something to do with that plastic plug to the sender which I should imagine is a bugger to replace as you cant easily get to it.

Only other thing I thought of doing would be how difficult would it be to fit a good quality auxiliary temp gauge? More I read up on these cars the more I see that the dials are prone to playing up a fair bit.

Flying Frank · 26-09-16, 01:24 PM

Just about every Audi I have had has temperature indications issues. Some are related to the gauge ( i.e. false/incorrect readings ) and others have been genuine and due to a sticking /faulty thermostat.

My V6 Audi 80 has dodgy readings but this time I think it's the thermostat....it bloody well would be as its such an epic to change the thermostat , hours of labour and the obligatory advice to then change the cam belt, water pump, tensioner, etc etc. Money money!

I suspect the problem with your gauge may just be a bad earth? The randomness of it certainly makes it sound like some sort of bad/incorrect signal getting up to the gauge. Back a few years ago when I had just joined CA Forum, I was having problems with an oil pressure switch warning and that turned out to be in the mini check computer.....diagnosed by Mikes2 and cured by Shaun5 supplying me with a replacement mini check 'puta. At least the water temp gauge doesn't go through a computer ( I don't think ) but finding the problem is hard...have you thought of just trying a substitute instrument cluster ( if you have one ) to see if the water temp gauge on that plays up the same ?

After market switches never seem to be as good as genuine Audi ones either.....trouble is that the Audi ones tend to cost 3 times as much.

p.s. I don't think you'll find a V6 cluster will work in your car as the rev counter will be giving wrong readings......

Crossle · 26-09-16, 02:58 PM

Thanks Frank, yes electrical problems are certainly a pain to trace arent they and I am certainly no electrician. I did forget to mention earlier actually I did change the thermostat so its not that. The car has had overheating issues in its time and with 172k on the clock I would rather know what temp I am sitting at in the rush hour traffic in the mornings ideally!

Flying Frank · 26-09-16, 03:03 PM

Bens trick of slackening off and re-tightening the two screws which secure the gauge behind the instrument cluster, worked for me on one occasion, but I gather you have tried that already.

So I'm now scratching my head too, I agree though that its one of the cars instruments I really do like to keep an eye on.

Flying Frank · 27-10-16, 04:51 PM

So Crossie, I'm now joining you in this thread as having bought the Audi 90 with 2.3 NG engine, i'm in the same boat as you.
Temperature gauge as dead as a dodo ( EXCEPT for one very brief occasion when it started to work and crept up to the quarter mark and then just died again for no apparent or logical reason ) My car has Autocheck so wonder if any signal goes through there and it could be an issue there?

Yes , I've changed the sender ( 25 euros ! ) and checked and untightened and re-tightened the screws on the back of the gauge. Also checked the inside of the plug in the engine bay and it appears to be squeaky clean.

Totally at a loss now.

Calling Ben and Mikes2 for any other suggestions please ?

Crossle · 27-10-16, 04:56 PM

Hi Frank- I've got mine working of sorts now. I took the electrical plug off the sender in the engine bay. Its a big brown multi connector on mine. As in the case with yours mine looked mint from the limited amount I could see in the confined area down the side of the block. I got a small screwdriver in and scraped it down the terminals, covered the whole thing in electrical cleaner and it works now and has done for the last 2-3 weeks. It does still flick about a bit randomly from cold but then settles to an read what you would expect to be an accurate reading for the rest of the journey. Not convinced its problem solved but I have a gauge that appears to be working 90% of the time.

Flying Frank · 27-10-16, 05:00 PM

Sender on mine is only a 2 pin affair, altho, there is another sender underneath the thermostat housing, maybe I'd better have a look at that.....very inaccessible of course! Thanks for the reply and will check the two plugs out altho' I think the lower one is just for the radiator fan ?

cjp0349 · 27-10-16, 05:17 PM

I've read with interest several threads on the forum about erratic fuel and temperature gauges on various vehicles but has anyone ever suggested hairline fractures on the solders of the gauges circuit boards which is certainly a common fault on other VAG products of a certain age. It certainly sorted the erratic fuel gauge on my old '92 T4.

http://www.1946vw.co.uk/vwbooks/vw_info/t4_gauges.htm

But only after I had run out of petrol on the M6

Flying Frank · 27-10-16, 06:32 PM

Yes, I had those problems back in the early 90's with one of my 80 Sports....there was a guy in the local VAG garage in Crawley who knew exactly where to find the break in the printed circuits too. Could sort the problem in 30 minutes approx.

But nowadays, one would hope for better things......but apparently Audis weak heel is still water temp gauges . And I live about 280 miles away from Crawley.

sinbin5t · 27-10-16, 06:35 PM

Quote:

Originally Posted by cjp0349

I've read with interest several threads on the forum about erratic fuel and temperature gauges on various vehicles but has anyone ever suggested hairline fractures on the solders of the gauges circuit boards which is certainly a common fault on other VAG products of a certain age. It certainly sorted the erratic fuel gauge on my old '92 T4.

http://www.1946vw.co.uk/vwbooks/vw_info/t4_gauges.htm

But only after I had run out of petrol on the M6

only just spotted this cjp

Been there in an Audi that told me the tank was half full but spluttered to a standstill with an empty tank !

26-09-16, 12:26 PM	#11
Crossle Grown up member Classic Audi Club Member Join Date: Jul 2015 Location: northampton Posts: 266	I am not sure what make it was to be honest, just got it from GSF car parts but on the odd occasion it did read with the old sender it always used to shoot up to 3/4 even if the engine had not been started and was stone cold- seems to e its very spot regardless of the sender I've had in it. Randomly today after initial flicking around for the first few miles it settled at just below half and stayed there which is probably a realistic reading. I think its the first time its done that on the last few months. Not really sure where to go with it now, think maybe I will have to get an Auto Electrician up as it would seem its something to do with that plastic plug to the sender which I should imagine is a bugger to replace as you cant easily get to it. Only other thing I thought of doing would be how difficult would it be to fit a good quality auxiliary temp gauge? More I read up on these cars the more I see that the dials are prone to playing up a fair bit. Last edited by Crossle; 26-09-16 at 12:28 PM.

26-09-16, 01:24 PM	#12
Flying Frank 4 ring whore! Classic Audi Club Member Join Date: Dec 2012 Location: Kernow, Gods own county !! Posts: 2,388	Just about every Audi I have had has temperature indications issues. Some are related to the gauge ( i.e. false/incorrect readings ) and others have been genuine and due to a sticking /faulty thermostat. My V6 Audi 80 has dodgy readings but this time I think it's the thermostat....it bloody well would be as its such an epic to change the thermostat , hours of labour and the obligatory advice to then change the cam belt, water pump, tensioner, etc etc. Money money! I suspect the problem with your gauge may just be a bad earth? The randomness of it certainly makes it sound like some sort of bad/incorrect signal getting up to the gauge. Back a few years ago when I had just joined CA Forum, I was having problems with an oil pressure switch warning and that turned out to be in the mini check computer.....diagnosed by Mikes2 and cured by Shaun5 supplying me with a replacement mini check 'puta. At least the water temp gauge doesn't go through a computer ( I don't think ) but finding the problem is hard...have you thought of just trying a substitute instrument cluster ( if you have one ) to see if the water temp gauge on that plays up the same ? After market switches never seem to be as good as genuine Audi ones either.....trouble is that the Audi ones tend to cost 3 times as much. p.s. I don't think you'll find a V6 cluster will work in your car as the rev counter will be giving wrong readings......

26-09-16, 02:58 PM	#13
Crossle Grown up member Classic Audi Club Member Join Date: Jul 2015 Location: northampton Posts: 266	Thanks Frank, yes electrical problems are certainly a pain to trace arent they and I am certainly no electrician. I did forget to mention earlier actually I did change the thermostat so its not that. The car has had overheating issues in its time and with 172k on the clock I would rather know what temp I am sitting at in the rush hour traffic in the mornings ideally!

26-09-16, 03:03 PM	#14
Flying Frank 4 ring whore! Classic Audi Club Member Join Date: Dec 2012 Location: Kernow, Gods own county !! Posts: 2,388	Bens trick of slackening off and re-tightening the two screws which secure the gauge behind the instrument cluster, worked for me on one occasion, but I gather you have tried that already. So I'm now scratching my head too, I agree though that its one of the cars instruments I really do like to keep an eye on.

27-10-16, 04:51 PM	#15
Flying Frank 4 ring whore! Classic Audi Club Member Join Date: Dec 2012 Location: Kernow, Gods own county !! Posts: 2,388	So Crossie, I'm now joining you in this thread as having bought the Audi 90 with 2.3 NG engine, i'm in the same boat as you. Temperature gauge as dead as a dodo ( EXCEPT for one very brief occasion when it started to work and crept up to the quarter mark and then just died again for no apparent or logical reason ) My car has Autocheck so wonder if any signal goes through there and it could be an issue there? Yes , I've changed the sender ( 25 euros ! ) and checked and untightened and re-tightened the screws on the back of the gauge. Also checked the inside of the plug in the engine bay and it appears to be squeaky clean. Totally at a loss now. Calling Ben and Mikes2 for any other suggestions please ?

27-10-16, 04:56 PM	#16
Crossle Grown up member Classic Audi Club Member Join Date: Jul 2015 Location: northampton Posts: 266	Hi Frank- I've got mine working of sorts now. I took the electrical plug off the sender in the engine bay. Its a big brown multi connector on mine. As in the case with yours mine looked mint from the limited amount I could see in the confined area down the side of the block. I got a small screwdriver in and scraped it down the terminals, covered the whole thing in electrical cleaner and it works now and has done for the last 2-3 weeks. It does still flick about a bit randomly from cold but then settles to an read what you would expect to be an accurate reading for the rest of the journey. Not convinced its problem solved but I have a gauge that appears to be working 90% of the time.

27-10-16, 05:00 PM	#17
Flying Frank 4 ring whore! Classic Audi Club Member Join Date: Dec 2012 Location: Kernow, Gods own county !! Posts: 2,388	Sender on mine is only a 2 pin affair, altho, there is another sender underneath the thermostat housing, maybe I'd better have a look at that.....very inaccessible of course! Thanks for the reply and will check the two plugs out altho' I think the lower one is just for the radiator fan ?

27-10-16, 05:17 PM	#18
cjp0349 Senior Member Classic Audi Club Member Join Date: Aug 2014 Location: Lune Valley, North Lancashire Posts: 1,744	I've read with interest several threads on the forum about erratic fuel and temperature gauges on various vehicles but has anyone ever suggested hairline fractures on the solders of the gauges circuit boards which is certainly a common fault on other VAG products of a certain age. It certainly sorted the erratic fuel gauge on my old '92 T4. http://www.1946vw.co.uk/vwbooks/vw_info/t4_gauges.htm But only after I had run out of petrol on the M6

27-10-16, 06:32 PM	#19
Flying Frank 4 ring whore! Classic Audi Club Member Join Date: Dec 2012 Location: Kernow, Gods own county !! Posts: 2,388	Yes, I had those problems back in the early 90's with one of my 80 Sports....there was a guy in the local VAG garage in Crawley who knew exactly where to find the break in the printed circuits too. Could sort the problem in 30 minutes approx. But nowadays, one would hope for better things......but apparently Audis weak heel is still water temp gauges . And I live about 280 miles away from Crawley.