Changing the thermostat housing on Volkswagen Polo 3 1.4 MPI

Detach the cables from the housing by pulling on them.

Remove the hose by pulling on it.

The back of the case is clipped. Simply pull it vertically to unlock it.

The housing remains connected to a hose which does not need to be uncoupled.

You can move the box to the passenger side.

Do not break the oil level dipstick.

Thermostat housing

Hoses connected to the housing .

The old housing broke and water was leaking through this hole hence the replacement.

Lower radiator hose to be removed for bleeding.

Hose clamp

Vase d'expansion

Cork

Water level probe

Suction hose

Discharge hose

Place your recovery bin under the car.

Remove the hose clamp.

Remove the hose.

Remove this ignition cable to make it easier to pass the multi-grip pliers.

To remove these 6 hoses, remove the hose clamps then the hoses by pulling on them.

Open these 2 staples by hand then remove the sheath.

Remove the staple by pulling on it.

Using an 8mm socket remove this screw.

Disconnect the probe.

Using a 10mm socket remove the 3 screws holding the housing to the cylinder head.

Old case

New case

Tapped holes for the 3 housing screws.

Using a cutter blade, clean the area around the seal as best you can.

Reassembly is carried out in reverse order.

Check that you have correctly replaced the hose that you removed for bleeding.

There is no bleeder screw on this model. The expansion tank being the highest point the air escapes through the return pipe.

Remember to buy coolant that meets the manufacturer's standards. For this VW you need G12.

Fill the jar to the max level and check that there are no leaks at the hoses and the housing .

Start the engine and let it run.

Now that the fluid is under pressure and circulating, double check for leaks at the hose and drain plug.

Let the temperature rise until the cooling fan starts.

Wait for the engine to cool down and then top up. The level should be between the Min and Max marks.