Removal, models 316i, 318i produced before August 1993 (M40 engine)
Attention: Since the removal of the oil pump requires a lot of preparatory work and is also rarely done, it is recommended that this work be carried out by a BMW workshop. To check the operation of the safety valve, it is enough to first remove the oil sump.
Remove toothed belt.
Remove vibration damper -1- from crankshaft (bolts -3-). In this case, turn on the 5th gear, tighten the hand brake and thereby block the engine.
Loosen bolt -5-. Remove toothed pulley -4- from crankshaft.
Attention: The bolt is screwed in with a large tightening torque. When removing the bolt, have an assistant depress the brake pedal to prevent the engine from turning over.
Remove key -7- from crankshaft and remove ring -8-.
Unscrew all toothed belt guide rollers from the engine block cover.
Remove water pump.
Remove oil sump.
Unscrew the pulse sensor from the cover.
Unscrew all bolts -arrows- for cover and remove cover.
Unscrew the 4 bolts from the back of the cover and pull out the oil pump gears.
Examination
Clean and check the oil pump. If there are signs of wear on the gears and pump housing, measure the pump and, if necessary, replace it. Specifications: radial play of the outer rotor in the pump housing: max. 0.2 mm; axial play of the inner rotor: max. 0.065 mm; outer rotor: max. 0.1 mm.
Release the retaining ring on the cover and remove the safety valve -b- (Drawing W 1059). Measure the unloaded length of the spring, replace if necessary. Set value: 84.1 mm.
Insert the safety valve, install the retaining ring.
Lubricate the rotors with engine oil and install. Screw on the oil pump cover with a tightening torque of 10 Nm.
Installation
Be sure to replace the cover gasket and the crankshaft O-ring.
Install the cover with a new gasket and tighten the bolts evenly. The tightening torque depends on the bolt thread size: threaded bolts M6:10 Nm; M8 threaded bolts: 20 Nm.
Lubricate the new crankshaft oil seal with engine oil and carefully drive it until it stops with a short tube. The inner and outer diameters of the tube must match the dimensions of the stuffing box. At BMW service stations, tool 112320 is used for this.
Put the ring on the crankshaft, insert the key and put on the toothed pulley.
Screw in bolt -5- with washer (Drawing W 1630). In this case, the protrusion of the washer should be facing the toothed pulley.
Tighten bolt -5- to 310 Nm.
Attention: A powerful tool is required. Engage 5th gear and, so that the engine does not crank, have an assistant press the brake pedal.
Screw on the vibration damper, while tightening the 6 screws to 25 Nm.
Install pulse sensor.
Install water pump.
Install toothed pulleys and toothed belt.
Install the oil sump.
Fill the engine with oil and coolant.
Connect ground wire to battery.
Start the engine and let it run at idle speed, adding gas if necessary. No later than 10 seconds later, the oil pressure warning lamp on the dashboard should go out, otherwise, find and fix the problem according to the engine lubrication system troubleshooting table.
Removal, models 320i, 325i, 32Bi
Unscrew and deflect the oil sump. The oil sump can only be removed on a removed engine when the oil pump has been removed.
Unscrew the nut, remove the oil pump sprocket with the chain. In doing so, unload the chain tensioner (wring out).
Attention: The nut has a left-hand thread, i.e. turn to the right when unscrewing.
Remove bolts -arrows- for oil pump. Do not lose the 2 centering sleeves for later installation.
Pull the oil sump back.
Examination
Disassemble and clean the oil pump: Unscrew the inlet pipe (bolts -13-). Do not lose 2 dowel sleeves -4- when doing this. Check rotors -2- and -3- for wear and scratches. Specifications: Radial play of the outer rotor in the pump housing: max. 0.18mm; axial play of the inner rotor: max. 0.08mm; outer rotor max. 0.09 mm.
Loosen the retaining ring on the cover and remove the safety valve -6- (see picture). Measure the unloaded length of the spring, replace if necessary. Set value; 84.1 mm.
Attention: Always renew O-ring -8-. Carefully insert safety valve, secure with circlip. Screw on the inlet pipe with a new gasket, the protrusion of the gasket must face the inlet box.
Lubricate all parts with engine oil. Screw on the oil pump cover with a tightening torque of 10 Nm.
Installation
Install oil sump with oil pump.
Insert oil pump. Tighten the bolts to 20 Nm. There must be 2 centering bushes between the engine block and the oil pump housing. Insert the chain sprocket and tighten the nut (left hand thread) with a tightening torque of 20 Nm. If removed, install chain tensioner.
Screw on the oil sump.