1  The thermostat housing in Fiat Punto car is bolted to the left-hand end of the cylinder head. The thermostat itself cannot be separated from the housing and can only be renewed as part of a complete assembly.


2  Drain the cooling system.
3  Remove the air cleaner assembly as.
4  Remove the battery and battery tray.
5  Remove the clip and detach the radiator top hose from the thermostat housing.
6  Unscrew the two securing bolts, and remove the thermostat housing from the cylinder head (see illustration). If it sticks, tap it gently first on one side and then the other to free it - do not lever between the mating faces. Recover the remains of the old gasket.

Unscrew the bolts, and remove the thermostat housing from the cylinder head


7  A rough test of the thermostat of Fiat Punto car may be made by suspending it with a piece of string in a container full of water. Heat the water to bring it to the boil and observe the movement of the valve shaft through the inlet port.
8  The thermostat valve must be fully open by the time the water boils. If not, renew the complete thermostat/housing assembly.
9  If a thermometer is available, the precise opening temperature of the thermostat may be determined; compare with the figures given in the Specifications. The opening temperature is also marked on the thermostat housing.
10   Note that a thermostat which fails to close completely as the water cools must also be renewed.


11   Ensure that the cylinder head and thermostat housing mating surfaces are completely clean and free from all traces of the old gasket material.
12   Lay a new gasket in position on the cylinder head, then fit the thermostat housing and insert retaining bolts. Tighten the bolts to the specified torque.
13   Refit the radiator top hose to the thermostat housing in Fiat Punto car and secure with a new retaining clip.
14   Refit the battery tray and battery.
15   Refit the air cleaner assembly.
16   Refill the cooling system.