Removal
1. Remove the pan as described in paragraph 15.
Engines ADP, ADR, AFY, AEB and AJL
2. On these engines the oil pump is driven from the auxiliary shaft.
3. On ADP engines, support the left and right subframes with a trolley jack, placing a piece of wood between it and the subframes. Mark the position of the subframes to maintain the wheel alignment angles after assembly. Remove the subframe mounting bolts. First, remove the two front bolts, then the rear ones. Lower the subframes together with the anti-roll bar to the floor.
4. Remove the oil deflector plate from the bottom of the crankcase.
5. Use a hex key to loosen the bolts and remove the oil receiver from the oil pump. Remove the sealing ring.
6. Remove the large bolts securing the oil pump to the block. If necessary, pull the subframe down to allow enough room to remove the oil pump.
7. Unscrew the two bolts and remove the cover. Note that the cover contains a pressure reducing valve.
AHL engines
8. On AHL engines, the oil pump is driven by a chain from the crankshaft nose.
9. Remove the oil deflector plate from the lower part of the cylinder block.
10. Unscrew the three mounting bolts and remove the oil pump from the crankcase bushings. Unhook the oil pump drive gear from the chain and remove the pump together with the oil receiver from the engine. The tensioner will try to tighten the chain, interfering with removal; you may have to hold it in a compressed position with a screwdriver.
11. Unscrew the flange mounting bolts and remove the oil receiver from the pump. Remove the sealing ring. Unscrew the mounting bolts and remove the cover from the oil pump.
12. Check the drive chain for wear and damage. To remove the chain, first remove the timing belt as described in paragraph 4, then unscrew the bolts securing the front oil seal housing to the cylinder block. After removing the housing, remove the chain tensioner, unhook the chain from the sprocket on the crankshaft nose.
Examination
13. On ADP, ADR, AFY, AEB and AJL engines, clean the components and check for wear or damage. Measure the clearance between the gears with a feeler gauge and compare it with the data given in Specifications. Measure the axial clearance in the same way, placing a steel ruler on the pump body. If the clearances exceed the permissible limits, the pump must be replaced. If the clearances are "within tolerances", install the cover and tighten the bolts that secure it.
14. On AHL engines, thoroughly clean the pump and check for wear and damage to the gear teeth. A puller is required to remove the sprocket from the crankshaft nose, but keep in mind that the sprocket must be heated to 220°C for 15 minutes to install. Also note that the wide ring on the sprocket must face the engine. To remove the sprocket from the oil pump, unscrew the mounting bolt and pull it off. Note that the sprocket can only be installed in one position. Check for wear and damage to the pump gears. If wear is obvious, replace the pump.
Installation
15. Fill the pump with oil by pouring it into the oil pickup hole and rotating the drive shaft.
Engines ADP, ADR, AFY, AEB and AJL
16. Clean the mating surfaces, install the cover on the pump and tighten the bolts to the specified torque.
17. Clean the pump and block, attach the pump, tighten the mounting bolts and tighten them to the specified torque.
18. Install a new sealing ring onto the end of the oil pickup tube. Install the oil pickup onto the pump, install the bolts and tighten them.
19. On ADP engines, install the subframes and tighten their mounting bolts to the specified torque as described in chapter 10.
20. Install the tray as described in paragraph 15.
AHL Engine
21. Install the cover onto the oil pump and tighten the mounting bolts securely.
22. If the chain, crankshaft sprocket and tensioner were removed, postpone their installation until after the oil pump is installed on the cylinder block. If they were not removed, use a screwdriver to push the tensioner against the spring to loosen the chain and install the pump.
23. Mount the pump on the bushings, tighten the three mounting bolts to the specified torque. If necessary, align the pump sprocket with the chain.
24. If necessary, install the pressure chain, crankshaft sprocket and tensioner in the reverse order of removal.
25. If necessary, install the crankshaft on the housing with the front oil seal. Apply a suitable sealant before installing the housing.
26. Install the reflector plate on the tray as described in paragraph 15.
(The original version is on the portal: AudiManual)