1   Remove the timing belt and crankshaft sprocket of Fiat Punto.
2  Drain the engine oil and remove the oil filter.
3  Remove the sump.
4  Remove the coolant pump of Fiat Punto.
5  Disconnect the wiring connector from the oil pressure switch on the side of the pump casing.
6  Undo the oil pump retaining bolts, noting the location of the longer bolt, and withdraw the pump assembly from the front of the engine. Recover the gasket.

7  With the pump on the bench, undo the two bolts and remove the pick-up tube. Using a small screwdriver or similar tool, hook out the pick-up tube sealing O-ring from the pump body.
8  The pressure relief valve components can be removed for examination by depressing the spring and pulling out the keeper plate (see illustrations).

Removing the oil pump pressure relief valve keeper plate

Oil pump pressure relief valve components

9  If pump wear is suspected, check the rotors in the following way. Extract the fixing screws and remove the rear cover plate of Fiat Punto. The screws are very tight, and will probably require the use of an impact screwdriver (see illustration).

Using an impact screwdriver to remove the oil pump rear cover plate screws

10   Inspect the pump rotors, pump casing and cover for any signs of wear or damage. If satisfactory, refit the rotors to the pump casing ensuring that the orientation marks are facing upwards.
11   Check the clearance between the outer rotor and the pump casing using feeler blades. Check the rotor endfloat by placing a straight-edge across the pump casing, and checking the gap between the straight-edge and rotor face (see illustrations). If the clearances are outside the specified tolerance, renew the oil pump complete.

Measuring the oil pump outer rotor-to-pump casing clearance

Measuring oil pump rotor endfloat

12   If the pump of Fiat Punto is unworn, lubricate the rotors with clean engine oil then place the cover plate in position. Apply thread locking compound to the retaining screws and tighten the screws securely.
13   Locate a new O-ring in the pump casing then refit the pick-up tube. Secure the tube with the two bolts tightened securely.
14   Lubricate the pressure relief valve components then refit the valve, spring and end cap, securing the assembly with the keeper plate.
15   Lever out the crankshaft oil seal and drive a new one squarely into the oil pump casing (see illustrations). Lubricate the oil seal lips with clean engine oil.

Removing the oil pump oil seal

Using a socket to fit a new oil seal to the oil pump

16   Prior to refitting, prime the pump of Fiat Punto by pouring clean engine oil into its inlet duct, while at the same time turning the oil pump inner rotor.

17   Ensure that the oil pump and cylinder block mating faces are clean, then place a new gasket on the pump casing. Retain the gasket in position by inserting two of the pump retaining bolts.
18   Locate the pump on the cylinder block of Fiat Punto, insert the retaining bolts and tighten them progressively to the specified torque.
19   Refit the coolant pump.
20   Refit the sump.
21   Refit the crankshaft sprocket and timing belt.
22   Reconnect the oil pressure switch wiring connector.
23   Fit a new oil filter then fill the engine with oil and coolant.