Coolant temperature going down when driving

[AK3123124]

Hi,
I have 2019 Seat Leon Se Dynamic Tsi Evo and it takes a long time for the engine coolant to warm up (around 15 minutes when stationary). However, once it reaches around 80/90 degrees it drops back down to 50 degrees when driving.

I am suspecting the issue being with the thermostat, however when looking for thermostats for my vehicle I cannot find any compatible.

Anybody have any recommendations or have had this issue in the past?

Thanks

 

[BillyCool]

Hi,
I have 2019 Seat Leon Se Dynamic Tsi Evo and it takes a long time for the engine coolant to warm up (around 15 minutes when stationary). However, once it reaches around 80/90 degrees it drops back down to 50 degrees when driving.

I am suspecting the issue being with the thermostat, however when looking for thermostats for my vehicle I cannot find any compatible.

Anybody have any recommendations or have had this issue in the past?

Thanks

Could be the thermostat misbehaving/sticking. Not sure if you have the electronic switchable water pump on your car. They can play up as well.

Have you put your reg in here: https://www.autodoc.co.uk/

You must be able to find an OEM part number and find what you need somewhere.

 

[AK3123124]

Could be the thermostat misbehaving/sticking. Not sure if you have the electronic switchable water pump on your car. They can play up as well.

Have you put your reg in here: https://www.autodoc.co.uk/

You must be able to find an OEM part number and find what you need somewhere.

Hi

Thanks for the reply, i put my number plate in the website you provided but still it says there are 0 results for thermostats for my car. I guess ill have to find the OEM part number. I just find it weird that no results come up for a thermostat for my vehicle and wondering if my vehicle even has one lol.

 

[redone]

ebay or amazon have ‘check compatibility with your car’ functions where the results are supposed to fit?

 

[LeylandVCDS]

ebay or amazon have ‘check compatibility with your car’ functions where the results are supposed to fit?

Unfortunately I've found the ebay compatibility checker very, very inaccurate. Far safer in these cases to go to the dealer - at least if the wrong one is supplied there is a comeback

 

[Ghostex]

Did you manage to sort this issue out and what was it if you did? Im having similar issues with my 2.0tdi where its taking a while to warm, the car will stay at operating temperature 90 degrees, but one i start driving the temperature will drop rapidly.

 

[AK3123124]

Did you manage to sort this issue out and what was it if you did? Im having similar issues with my 2.0tdi where its taking a while to warm, the car will stay at operating temperature 90 degrees, but one i start driving the temperature will drop rapidly.

Didn't sort out the issue because the weather got warmer and it stopped dropping, im suspecting it's the thermostat but I cant find the part for my car on any websites. Going to sort out the issue for this winter in the next couple of days

 

[nd-photo.nl]

Just go to the dealer and provide your VIN. This is most likely a faulty thermostat. Failure to address it also has a negative impact on your mileage as it will overfuel

 

[SuperV8]

Didn't sort out the issue because the weather got warmer and it stopped dropping, im suspecting it's the thermostat but I cant find the part for my car on any websites. Going to sort out the issue for this winter in the next couple of days

Assuming you have a 1.5tsi? - you have a combined pump and thermostat. This includes 2x thermostats!

example: 05E121111AB

 

[SuperV8]

Did you manage to sort this issue out and what was it if you did? Im having similar issues with my 2.0tdi where its taking a while to warm, the car will stay at operating temperature 90 degrees, but one i start driving the temperature will drop rapidly.

Different engine to the OP.
The TDI has a couple of versions of thermostat housing, but if your temps go down when you start driving (in the cold) I would first suspect your thermostat.

 

[LeylandVCDS]

Maybe not down to 50 degrees, but I thought it was normal for the coolant temperature to rise from a cold start, then drop when the thermostat opens?
Both my previous 1.6TDI and my current 2.0TDI sees a rise up to 80 degrees, then a significant drop down to around 68 degrees before rising again all the way up to a steady and constant 90 degrees

 

[SuperV8]

Maybe not down to 50 degrees, but I thought it was normal for the coolant temperature to rise from a cold start, then drop when the thermostat opens?
Both my previous 1.6TDI and my current 2.0TDI sees a rise up to 80 degrees, then a significant drop down to around 68 degrees before rising again all the way up to a steady and constant 90 degrees

My 2.0 TDI doesn't do any drop on the coolant temp gauge. Just Goes up steadily to 90. It has a slight pause at higher temps (not a dip - just a slower rise) - while the thermostat is slowly opening and blending the large radiator circuit with the micro (heater matrix) circuit.
Thermostats aren't just open of closed like flood gates - they slowly open and vary depending on cooling requirement.