Do it yourself
Frequently asked questions about cars and motorcycles
Car tutorial (Do it yourself) Motorcycle tutorial (Do it yourself) Frequently Asked Questions

How to Replace the Thermostat on a Seat Leon MK3 2.0 TDI

Model: Seat Leon MK 3, 5F - Years 2012-2019
Part: Thermostat

Learn how to replace the thermostat on a Seat Leon: this is a rather complex operation that requires good mechanical knowledge. Start by relieving the pressure in the cooling system, then remove the engine cover and locate the thermostat at the rear of the engine, under the intake manifold, on the lower left. To remove the thermostat, you can work from above, but this is a blind operation, done by feel. The thermostat is secured in the housing by a bayonet lock ring: press the tab inward and rotate the entire thermostat counterclockwise. Once unlocked, pull it out of its housing, being careful not to damage the O-ring. You can find the new thermostat, for example, on auto-doc.it with code 180454 for €52.83 plus €9.95 shipping. For the installation of the new part, it has a specific orientation: of the three tabs, two must face upwards and one downwards. Fit the new O-ring, applying a thin layer of silicone grease to improve the seal, then rotate the thermostat clockwise. Refit the engine cover, top up the coolant, start the engine, and let it warm up at idle. The only alternative to this "blind" work is to remove the intake manifold, which is a time-consuming and demanding task.

Posted on 11 April 2026 by ScegliAuto

Video tutorial

Related tutorials

How and When to Replace the Timing Belt on the Seat Leon 1.6 TDI?
How and When to Replace the Timing Belt on the Seat Leon 1.6 TDI?
Seat Leon (2012-2019 / MK 3, 5F) This guide provides the necessary instructions on how to remove and replace the timing belt on the Seat Leon 1.6 TDI; the manufacturer states in the …
Layout and positioning of the fuses of the Seat Leon 1.6 TDI
Seat Leon (2012-2019 / MK 3, 5F) Shortly, we will see the positioning and layout of the fuse boxes of the Seat Leon 1.6 TDI. First, we open the hood of the car and start removing the…
How to Remove the EGR Valve from a Seat Leon 1.9 TDI
How to Remove the EGR Valve from a Seat Leon 1.9 TDI
Seat Leon (2005-2013 / 1P) Today, we will go through the instructions to remove and replace the EGR valve on a Seat Leon 1.9 TDI. First, raise the vehicle and begin by removing…

Other guides you may be interested in

How to Check the Oil Level on a Jeep Renegade?

To check the oil level on a Jeep Renegade, you need to open the bonnet to access the components inside the engine bay: on the lower left side of the engine block, you will find the dipstick for checking the level. This should be pulled out and thoroughly cleaned with a cloth: once cleaned, reinsert it back into its tube and pull it out immediately after. This way, you can check that the oil mark is between the minimum and maximum levels; finally, you can place the dipstick back in its tube.

Watch the video!


by ScegliAuto

More videos