Coolant temperature sensor

[Pittodrie]

I believe that I have a faulty coolant temperature sensor on my 2013 Exeo 143 estate.

Having watched a few YouTube videos on changing the coolant temperature sensor on various VAG cars I thought that it would be a relatively easy job to do on the Exeo. Apparently not! It would appear that the sensor is located at the back of the engine below the vacuum pump and close to the bulkhead and access seems ridiculously complicated.

Have I properly identified the location of the sensor?

Has anyone changed this sensor and can offer me any tips on how best to do it?

Any advice gratefully received. Thanks

 

[JR_130]

I believe it is #37 in this diagram http://www.oemepc.com/seat/part_sin...category/121040/part_id/1402618/lang/e#sec_34
but also i'm led to believe there is an additional thermostat in pipe #23
I've not looked at changing mine, despite the temp dropping in the winter.

what symptoms have you got that makes you want to change the thermostat?
it is apparently normal for the coolant temp to drop in cold weather whilst the car is idling (e.g. sitting in traffic), and changing the thermostat has little to no impact on this (hence why i haven't changed mine)

Edit, this diagram also shows thermostat housing at the engine block, now i'm confused
http://www.oemepc.com/seat/part_sin...bcategory/121005/part_id/1408437/lang/e#sec_6

 

[Pittodrie]

I believe it is #37 in this diagram http://www.oemepc.com/seat/part_sin...category/121040/part_id/1402618/lang/e#sec_34
but also i'm led to believe there is an additional thermostat in pipe #23
I've not looked at changing mine, despite the temp dropping in the winter.

what symptoms have you got that makes you want to change the thermostat?
it is apparently normal for the coolant temp to drop in cold weather whilst the car is idling (e.g. sitting in traffic), and changing the thermostat has little to no impact on this (hence why i haven't changed mine)

Edit, this diagram also shows thermostat housing at the engine block, now i'm confused
http://www.oemepc.com/seat/part_sin...bcategory/121005/part_id/1408437/lang/e#sec_6

Thanks for taking the time to reply to my post. I am pretty sure that it is part no 16 that I am looking to change albeit my engine appears to be slightly different to the one in the diagram and the coolant temperature sensor is in a significantly difficult location to access.
I have had the car about 4 years and I have never noticed any fluctuations in the temperature gauge until recently. Having read various bits and pieces on the internet it seemed to be that the sensor having become faulty was a likely cause of the issue and it seemed that the sensor was a fairly easy part to change. Not on my engine it isn’t!
Other than the fluctuations in the coolant temperature the car seems to be running normally.

 

[JR_130]

you can go up 1 level and select the diagram associated with your engine code (e.g., mine is CAHA)
http://www.oemepc.com/seat/parts_ls...011/drive_standart/664/hg/1/catalog/se/lang/e

also, did you get the car scanned with VAGCOM to verify there is an issue with the sensor before replacing it?

 

[Pittodrie]

you can go up 1 level and select the diagram associated with your engine code (e.g., mine is CAHA)
http://www.oemepc.com/seat/parts_ls...011/drive_standart/664/hg/1/catalog/se/lang/e

also, did you get the car scanned with VAGCOM to verify there is an issue with the sensor before replacing it?

Thanks again for your interest.
I am basing my fault diagnosis purely on what others seem to have experienced in terms of symptoms associated with a faulty coolant temperature sensor. I have noted that the sensor fitted to my engine appears to be the grey coloured model which it seems was superseded by a green coloured one, possibly because of reliability issues with the earlier model. Extremely untechnical in terms of fault diagnosis but my thinking was that the sensor is a sub £10 part and if it could be easily replaced then it was a cheap job if it resolved the issue and not a bank buster if it didn’t. Seemed like a good plan until I realised how inaccessible the sensor is on my engine.

 

[JR_130]

good point, I didnt realise the cost of the sensor was so little.
might it be any easier with the lower engine cover removed? - only an extra 10 mins if you have access to ramps?

 

[Pittodrie]

good point, I didnt realise the cost of the sensor was so little.
might it be any easier with the lower engine cover removed? - only an extra 10 mins if you have access to ramps?

Thanks for the continued interest.
I am fairly limited in mechanical skills and I had actually taken the car to a mechanic as, prior to seeing where the sensor is actually located, I thought that it would be a five minute job for him. As I mentioned earlier the sensor is in a horrible location in terms of accessibility and despite his best efforts to access the sensor he was unable to do it from either the top of the engine and it looks even more difficult from underneath while the car is on the ramp.
The mechanic feels that he will need to remove the vacuum pump to give him the opportunity to access the sensor. That seems to create an issue with regards to fitting a replacement gasket for the vacuum pump as that appears to be a multi component gasket and in my mind would be extremely difficult to fit. It was because the task seems overly complicated for the replacement of a sensor that I thought I would try this forum in the hope that someone has done it before and can offer up a tip that will make the job simpler than it appears.
I take on board your observation that it may be easier living with the occasional fluctuations in the temperature gauge and shelving the plan to replace the sensor in the meantime.

 

[Nollywood]

I’ve replaced the same sensor on a 2009 Audi A4 B8 CR 143.

Awkward, but nut too terrible. It took me about 40 minutes to complete the task. Compared to 11 hours to replace a sensor on a 2007 Volkswagen Touareg 5.0 V10 TDI. I had to pull the entire motor, transmission (a monster) and front subframe. Engine can’t be pulled on its own (another monster).

Sensor - £37.
Labour - £660.

Volkswagen dealerships charge labour £1265. So, I’d say you’re lucky!

 

[Pittodrie]

I’ve replaced the same sensor on a 2009 Audi A4 B8 CR 143.

Awkward, but nut too terrible. It took me about 40 minutes to complete the task. Compared to 11 hours to replace a sensor on a 2007 Volkswagen Touareg 5.0 V10 TDI. I had to pull the entire motor, transmission (a monster) and front subframe. Engine can’t be pulled on its own (another monster).

Sensor - £37.
Labour - £660.

Volkswagen dealerships charge labour £1265. So, I’d say you’re lucky!

Thanks for your input

That puts a great deal of perspective on my slight issue.

The accommodating mechanic whom I frequent managed to change the sensor yesterday. It is difficult to know how my engine compares to the one on your A4 but in terms of time it took slightly longer than 40 minutes. Once he had managed to create a narrow access route and had swapped over the sensors, the biggest difficulty was getting the securing clip back in place as he was essentially doing it by feel and the clip wasn’t for going on easily.

Suffice to say the sensor is changed and time will tell whether the original one was the cause of the fault I had observed.

 

[Pittodrie]

Has it cured the fluctuations in temp readings?

As far as I can see the temperature gauge is back to performing normally. I have also noticed a slight improvement in my fuel consumption since the sensor was replaced and this reinforces my belief that the original one was duff.