Hello everyone,

At the moment, I have an issue with my Skoda Superb (year 2018).

At high speeds (around 180–200 km/h) or when driving on steep routes, the coolant temperature on the dashboard rises above 90°C. As soon as I reduce the speed, the coolant temperature drops back to 90°C.

With VCDS, I found out that the G83 temperature sensor is stuck at 88°C. This means that even when I start the car cold, the sensor already shows 88°C. As a result, the fan doesn’t switch on in time.

Does anyone know where I can find the G83 coolant temperature sensor? I checked under the car near the radiator but couldn’t locate it. The other coolant sensor, G62, is working properly.

Best regards

Good morning, welcome to the forum.

Please can you say what engine you have? - with engine code if possible.

Hello, according to a post on the VW Audi forum, the G83 sensor is located on the side of the engine above the gearbox in a plastic junction - remove the air filter box to access.

Hi, thanks for your reply.

I have the 2.0 TDI EA288 engine.

I also read all the forum topics about the G83, but I still couldn’t find the sensor. I checked under the air filter box as well, but I didn’t see any sensor connected to the coolant pipe. I also took a picture from under the air filter box.

2 hours ago, token_454 said:

Hello everyone,

At the moment, I have an issue with my Skoda Superb (year 2018).

At high speeds (around 180–200 km/h) or when driving on steep routes, the coolant temperature on the dashboard rises above 90°C. As soon as I reduce the speed, the coolant temperature drops back to 90°C.

With VCDS, I found out that the G83 temperature sensor is stuck at 88°C. This means that even when I start the car cold, the sensor already shows 88°C. As a result, the fan doesn’t switch on in time.

Does anyone know where I can find the G83 coolant temperature sensor? I checked under the car near the radiator but couldn’t locate it. The other coolant sensor, G62, is working properly.

Best regards

Hi

Do you have more information:

- The coolant temperature on the dashboard rises above 90°C - by how much (maximum temperature)?

- The G83 temperature sensor is stuck at 88°C. Maybe the car hasn't this sensor?

Hi, the coolant temperature rises above 110°C, depending on how much I accelerate and press the gas pedal. This mostly happens in summer temperatures, at speeds between 180–200 km/h, or when driving around 150 km/h on a steep highway section. When I reduce the speed to under 130 km/h, the temperature goes back to normal.

I tracked this with VCDS while driving. I also noticed that the cooling fan activates too late. The fan only goes to 100% once the temperature reaches 110°C. Mostly the cooling fan is on 10.2%.

The car doesn’t seem to have the temperature sensor… hmm, that’s a good question. 😅

3 minutes ago, token_454 said:

Hi, the coolant temperature rises above 110°C, depending on how much I accelerate and press the gas pedal. This mostly happens in summer temperatures, at speeds between 180–200 km/h, or when driving around 150 km/h on a steep highway section. When I reduce the speed to under 130 km/h, the temperature goes back to normal.

I tracked this with VCDS while driving. I also noticed that the cooling fan activates too late. The fan only goes to 100% once the temperature reaches 110°C. Mostly the cooling fan is on 10.2%.

The car doesn’t seem to have the temperature sensor… hmm, that’s a good question. 😅

3 hours ago, token_454 said:

Hello everyone,

At the moment, I have an issue with my Skoda Superb (year 2018).

At high speeds (around 180–200 km/h) or when driving on steep routes, the coolant temperature on the dashboard rises above 90°C. As soon as I reduce the speed, the coolant temperature drops back to 90°C.

With VCDS, I found out that the G83 temperature sensor is stuck at 88°C. This means that even when I start the car cold, the sensor already shows 88°C. As a result, the fan doesn’t switch on in time.

Does anyone know where I can find the G83 coolant temperature sensor? I checked under the car near the radiator but couldn’t locate it. The other coolant sensor, G62, is working properly.

Best regards

I would have thought that at 180+ kph there would be plenty of cooling air without the fan. Perhaps the issue is the dreaded shrouded water pump sticking or at least not fully opening? Although I am not sure if this particular engine has it, I think most diesels Skodas do.

Edited 26 August, 202526 Aug by nicknorman

Hi, at the beginning I also thought that the water pump was stuck. I replaced the water pump and installed a non-electric one, but this didn’t change the behavior.

Another possible cause could be the thermostat, but I think I would notice that at lower speeds if it wasn’t working properly.

The car doesn’t have any other issues. It also has enough coolant, the level stays constant, and there are no leaks.

Edited 26 August, 202526 Aug by token_454

2 hours ago, token_454 said:

That indicated temperature (125) on the Maxi dot display is for the OIL temperature, isn't it?

2 hours ago, Warrior193 said:

That indicated temperature (125) on the Maxi dot display is for the OIL temperature, isn't it?

Hi, the oil temperature is 125 degrees. You see in the below picture in blue circle that the cooling temperature has pass 90 degrees. It goes further if i press the gas pedal

I'd avoid driving at those temperatures. The aluminium cylinder heads are a bit fragile. The G83 is usually in the cylinder head somewhere near the top. It almost certainly will have one. There is sometimes a second sensor (G83) which will be near the outlet at the bottom of the rad. That measures the coolant temperature after it leaves the rad. 125 c is just above the maximum for the oil temperature. Have a look around the top layer of the head. If you are not sure, take a wire off and see what vcds identifies for you. 🙂

28 minutes ago, Rheumy said:

I'd avoid driving at those temperatures. The aluminium cylinder heads are a bit fragile. The G83 is usually in the cylinder head somewhere near the top. It almost certainly will have one. There is sometimes a second sensor (G83) which will be near the outlet at the bottom of the rad. That measures the coolant temperature after it leaves the rad. 125 c is just above the maximum for the oil temperature. Have a look around the top layer of the head. If you are not sure, take a wire off and see what vcds identifies for you. 🙂

The sensor on the cylinder head is G62. I found this sensor by disconnecting the wires and checking in VCDS, which then showed a G62 error. However, I cannot find the G83 sensor. In the following link, I uploaded a video filmed from the bottom of my car where the coolant pipes are visible. I can not see any sensor.

Streamable

Watch unnamed | Streamable

It's possible it doesn't exist on your model. If you look at the live data where you saw what the G62 was reporting (Advanced Measuring Blocks) you may see data for the G83 listed. If it's not there it your model doesn't have it. If you see data marked G83 it does. It's main purpose is to check the efficiency of the rad. It's normally reading 60 or so degrees below the reading from the G62. I think if you replace the G62 with a genuine sensor your problems should be over assuming the head gasket hasn't been cooked or head warped which hopefully it's not.

42 minutes ago, Rheumy said:

It's possible it doesn't exist on your model. If you look at the live data where you saw what the G62 was reporting (Advanced Measuring Blocks) you may see data for the G83 listed. If it's not there it your model doesn't have it. If you see data marked G83 it does. It's main purpose is to check the efficiency of the rad. It's normally reading 60 or so degrees below the reading from the G62. I think if you replace the G62 with a genuine sensor your problems should be over assuming the head gasket hasn't been cooked or head warped which hopefully it's not.

In the picture below, I can select the sensor “Coolant temperature sensor at radiator output”. That should be the G83 sensor.

What do you mean by replacing the G62 sensor with a genuine sensor?

Apologies, in one earlier post I typed G83 for both coolant sensors. For clarity, the G83 is the cooler radiator outlet one and the G62 reads the hotter coolant as it leaves the head. Therefore I would change the G83 first since it's stuck. I'm surprised that the G83 could be used in controlling the fan because it always reads much less but I am more used to VW diesels these days. Obviously the wiring to the sensor could be at fault but the sensors do fail after a few years.

8 minutes ago, Rheumy said:

Apologies, in one earlier post I typed G83 for both coolant sensors. For clarity, the G83 is the cooler radiator outlet one and the G62 reads the hotter coolant as it leaves the head. Therefore I would change the G83 first since it's stuck. I'm surprised that the G83 could be used in controlling the fan because it always reads much less but I am more used to VW diesels these days. Obviously the wiring to the sensor could be at fault but the sensors do fail after a few years.

My first idea was to replace the sensor myself, but I couldn’t find its exact location. In the end, I will have to go to a repair shop and let them replace the sensor. I hope this will solve the issue. If not, I would consider replacing the thermostat, since it might be faulty and not opening correctly.

isn't 125 for engine oil too much too ?

i was driving quite hard on my tsi uphill and it was 115.

maybe you should check if cooler fins aren't blocked by some leaves ?

Edited 26 August, 202526 Aug by dilino

15 hours ago, token_454 said:

In the picture below, I can select the sensor “Coolant temperature sensor at radiator output”. That should be the G83 sensor.

What do you mean by replacing the G62 sensor with a genuine sensor?

On screen

First value is the for sensor G62 50deg - sensor on engine.

Second value for sensor G83 is the cooler radiator outlet one - 88 deg which is calculated by ECU when car has only G62 sensor.

23 minutes ago, mez2008 said:

On screen

First value is the for sensor G62 50deg - sensor on engine.

Second value for sensor G83 is the cooler radiator outlet one - 88 deg which is calculated by ECU when car has only G62 sensor.

I didn't know that but It makes sense. 👍

I know you say you have changed the water pump but all that you are saying are symptoms of a water pump stuck sleeve on the 2.0TDi.

1 hour ago, logiclee said:

I know you say you have changed the water pump but all that you are saying are symptoms of a water pump stuck sleeve on the 2.0TDi.

The pump cannot be stuck, because I installed a non-electric pump. These non-electric pumps were used in older cars, such as 2010 VW models. Even before I replaced the pump, the car already had the same temperature problem. This means that changing the pump did not change the behavior 😐

4 hours ago, mez2008 said:

On screen

First value is the for sensor G62 50deg - sensor on engine.

Second value for sensor G83 is the cooler radiator outlet one - 88 deg which is calculated by ECU when car has only G62 sensor.

But in my case, if the sensor were not physically installed, then the value for G83 should change and not always stay fixed at 88°C, assuming the ECU is just calculating this value. That means there must actually be a physical G83 sensor 😅

If you tell me the VIN, I can check whether the parts catalogue suggests your car should or should not have a G83 sensor.

I will start a private message conversation with you so that you don't have to put the VIN in public view.

For the VIN you supplied, I'm only finding one temperature sender listed, part number 04E919501B, superseded by 04L919501.

No other search results come up when I use search terms 'temperature sensor' (instead of sender") with any relevance to the coolant system. Nor for "radiator outlet".

I think I would conclude that G83 isn't fitted on this car.

I'll have a quick double-check by consulting wiring diagrams.