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

Model: Seat Leon 5F, MK 3 - Years: 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019
Part: Thermostat

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Video tutorial

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


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by ScegliAuto

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