First, drain out the coolant. The easiest way is to undo the lower radiator hose and let it piss out the bottom. The lower radiator hose is located at the bottom (surprise surprise!) of the radiator and to the left .
(Looking at the car) Red arrows indicate location.
Access usually requires removing the fan, which is held on by a pair of 8mm nut and bolts on the top of the rad. Also unplug the fan's electric connector, and lift it out.
Undo the hose clip, which if you're lucky will be a jubilee worm drive-type which you just unscrew. If you're unlucky it's an original crimped-style one which will need butchering off with snips and pliers. Replace with jubilee clips.
Place a container under the area of the hose to collect the coolant if desired. Also take the expansion tank cap off to help draining. Once drained, you can remove the thermostat housing held on by 5 Torx bolts.
Thermostat housing shown with air inlet trunking removed for clarity. Access to all screws requires the
ISCV to be removed - 2 bolts. Just move it to one side.
Now you can remove the stat housing to reveal the thermostat inside. This just locates in the bore with a rubber grommet attached to the thermostat. Note which way round it is facing.
Now if you want you can remove all the hoses to the thermostat housing (probably easier to do this before detaching from head) and and remove the housing from the car to clean up.
The mating surface on the head, remove old thermostat, insert new shiny one.....
.....apply a small bead of sealant on mating surfaces and bolt it back to the head. Don't go overboard tightening the bolts as Torx round off easily and they are bolting into aluminium which easily strips.
Replace all the bolts/hoses and the
ISCV. If this needs a clean, refer to Chris H's '16V
ISCV Cleaning' guide in the Engine/Mechanical section of the Knowledge Base.
At the same time you can change the radiator fan switch. This is located on the left hand-side of the fan (looking from front of car). Just above the lower radiator hose.
Unplug the connector - this needs a 30mm deep socket to undo. Using a spanner is difficult due to access. I found getting at it with an extension the easiest way so.....
.....get new shiny one and insert.
Reconnect the electrical connector.
Now ensure all hoses are done up tight, and fill the system back up, bleeding appropriately.
Start engine and fast idle, keeping an eye out for leaks. Make sure the fan kicks in when it should. Leave it to cool and top up coolant level if necessary.
Linear Mode
