Oil pump and pickup - removal, inspection and refitting

Engine in-car repair procedures / Oil pump and pickup - removal, inspection and refitting

General information
1 The oil pump and pickup are both mounted at the timing belt end of the crankcase. Drive is taken from the crankshaft via a chain and sprocket (see illustration).

14.1 Exploded view of the oil pump assembly

Removal
2 Refer to Section 13 and remove the sump from the crankcase.

3 With reference to Section 8, remove the front (timing belt end) crankshaft oil seal and housing.

4 Slacken and remove the bolts securing the oil pump to the end of the crankcase.

5 Remove the screws securing the oil pump pickup to the crankcase bracket.

6 Disengage the pump sprocket from the drive chain and remove the oil pump and pickup from the engine.

Inspection
7 Remove the screws from the mating flange and lift off the pickup tube. Recover the Oring seal.

8 Slacken and withdraw the screws, then remove the oil pump cover.

9 Clean the pump thoroughly and inspect the gear teeth for signs of damage or wear. Where applicable, check the condition of the oil pump drive chain; if the links appear excessively worn or are particularly loose, renew the chain.

10 Check the pump backlash by inserting a feeler blade between the meshed gear teeth: rotate the gears against each other slightly, to give the maximum clearance (see illustration).

14.10 Checking the oil pump gear backlash

Compare the measurement with the limit quoted in Specifications.

11 Check the pump axial clearance as follows: lay an engineers straight edge across the oil pump casing, then using a feeler blade, measure the clearance between the straight edge and the pump gears (see illustration).

Compare the measurement with the limit quoted in Specifications.

14.11 Checking the oil pump gear axial clearance

12 If either of the measurements is outside of the specified limit, this indicates that the pump is worn and must be renewed.

Refitting
13 Refit the oil pump cover, then fit the screws and tighten them to the specified torque.

14 Reassemble the oil pickup to the oil pump, using a new O-ring seal. Tighten the retaining screws to the specified torque.

15 Offer up the oil pump to the end of the crankcase. Fit the drive chain over the oil pump sprocket, then engage it with the crankshaft sprocket.

16 Fit the pump mounting bolts and hand tighten them.

17 Tension the drive chain by applying finger pressure to it at a point midway between the two sprockets (see illustration). Adjust the position of the pump on its mountings until the tension is within the limit given in Specifications.

On completion tighten the mounting bolts to the specified torque.

14.17 Checking the oil pump drive chain tension

18 Fit and tighten the fixings for the pickup tube to crankcase bracket.

19 With reference to Section 8, refit the crankshaft oil seal housing, using a new gasket and oil seal.

20 Refer to Section 13 and refit the sump.