UK-POLOS.NET - THE VW Polo Forum

Hi Guys,

I've been reading your forums for a while and thought I had got to the bottom of a weird temp gauge problem so replaced the sensor.
The gauge has been reading normal when car sat on tick over but as soon as I start driving it goes to zero. Replaced the sensor and still have the same issue.
I noticed a bit of oil had dripped down onto the sensors, (seems there are two on mine) so cleaned the plug out too but I may have missed some but not convinced the issue is here.
Its a 1995 1.6 GLX with air con leccy windows and sports seats all working fine, touch wood. Tick over is rock steady just about 900 rpm and it doesn't seem to be loosing oil or water
so I'm a little bemused as it seems to be a little rocket ship that drives very well. Only done 85000 so its not been worked hard by the looks of it. To be honest I've only bought it as a stop gap until I get my big Toyota Estima back on the road
so don't really want to spend loads on it, but a faulty temp gauge freaks us old uns out a bit lol.

1st daft question, where is the thermostat on this car?

2nd daft question, what is the other sensor for which is sat next to the temp sensor?

I'm sure I'm being thick so thought I would ask the experts.

Cheers for any help/advice you can give.

Pete

Keeping my fingers crossed someone has some ideas.
Any suggestions very much appreciated.

Thanks

Pete.

im sure the thermostat is behind the engine itself, ie near to the firewall, it should be a green type of plug
mine was faulty, saying it was overheating... i took mine out clean it and the area up a bit and it worked alright

as for the other plug, im not too sure, pictures could help identify it though?

cheers
John

Hope this pic shows. Not good with these forums lol.



I have replaced the sensor on the left with the yellow ring, the one that came out also had a yellow ring on it.

Not sure what the other sensor is as I havent been able to source a haynes manual yet.



Is the thermostat housing under the HT leads? I mean the leads to the right not the ones on the dizzy cap. It looks like it might be but the hose on it seems to go to the bottom of the rad!
I know nothing about VW's having never had one before so I appreciate any advice any one can give.

Cheers

Pete

The one with the yellow ring is the engine/clocks temp sender. I replaced one on a customers polo the other day

As for the thermostat housing, those sensors plug into the thermostat housing - the thermostat is located inside there.

Where did you get the temperature sensor from?

I also recommend getting it plugged into vagcom as that will give you more clues as to what the problem is coming from.

Hi Alex,

I got the sensor from gsf, did I do wrong? Are they no good?

I've also noticed the milometer shows 1n02 on start up for a few seconds if thats a clue.
I have to admit to being confused as to where the thermostat is housed as the bit with the sensors just have a pipe coming off them in a straight line so to speak, dosn't like a thermo housing but then again I just dont know these cars.

Cheers
Pete

1n02 thats interesting

As for the sensor, you did nothing wrong as such...GSF sensors are renowned for their s**t quality and failing often out of the box. If you want it to work and keep working you have to buy genuine sensors. More pricey, but the GSF ones often need replacing after a much shorter time.

Oh Bugger!

I thought it might at least eliminate a possibilty lol.

What does the 1n02 mean?

Ah ok, the tinterweb seems to suggest it needs a big service which I'm happy to do once Ive sorted the temp gauge issue.

Means Inspection Service 2 - your due a full service ie oil air filter etc

Thanks Alex, you beat me to it lol.

I've got to try and make a decision re the sensor now. Is it likely to be duff or should I do the thermostat check next do you think. Its my only means of transport and I'm strapped for cash so got to be careful.
Is there a way to test the sensor?

Cheers for advice.
Pete

Theyll take it back fi you tell them its not working

I find it unlikely that the thermostat would be at fault, as the temp is measured on the engine side, and not the thermostat side.

Hi Alex,

Thanks for your reply. I will try and get another sensor if I can raise the cash to get a genuine VW one, just so strapped for cash at the mo.
I wonder if anyone has any ideas as to what else it could be if it isn't the sensor or thermostat. Its using quite a lot of fuel at the moment 80 miles on £25 seems like too much to me.

Temp sensor can cause huge fuel issues

Another thing causing massive fuelling issues is the lambda sensor.

Realistically, you need to get the car plugged into vagcom and have the fault codes read to help diagnose the fault.

I take it that plugging in needs to be done at a main dealer? Do they charge much?
I sound like a right skint flint but I've just been laid off work, so cash is just not there at the moment but obviously without some dosh its going to be almost impossible to identify the fault. Catch 22.

Not necessarily. Alot of us on here have access to the vagcom software - where are you based?