Withdrawal
Attention: Operations and instructions applicable to all diesel engines are given in the 525tds engine chapter. Only the differences that apply to the 520d engine are described below. The method of tightening the cylinder head bolts is also suitable for the 530d engine, the tightening sequence is the same as for the 525tds engine.
Cylinder head gasket defect is determined on several grounds.
Since the removal of the cylinder head is quite laborious and is carried out using a special tool from BMW, it is recommended to contact a BMW workshop for work.
Remove intake manifold.
Remove replacement element engine air filter.
Remove fuel lines high pressure and injectors.
Remove bolts -1- and remove intake manifold.
Unplug connector -2- by pushing the wire lock of the connector down.
Loosen the cylinder head cover bolts in a crosswise manner in sequence from 22 to 1, see below fig. W-10372.
Drain the coolant, including from engine block.
Press the wire clamps with a screwdriver and disconnect the coolant hoses going to the radiator from the thermostat housing.
Unbolt turbocharger to exhaust manifold -arrows-.
Remove EGR cooler -1- together with thermostat To do this, loosen coolant hose clamps under EGR cooler and disconnect coolant hoses. Unscrew bolts -3- for fastening the flange and bolts -4- at the bracket on both sides of the cooler of the EGR system.
Unbolt the coolant pipe to cylinder head under the thermostat housing. Unbolt the pipe fitting to the cylinder head bracket.
Remove both camshafts.
In the marked places -arrows-, unscrew the support pins of the film of the damper and the chain tensioner.
Note: The left finger in the picture is covered by a vacuum pump.
Pull the tensioner bar upwards.
Unscrew securing bolts -arrows- for chain shaft. Screw out bolts -1- and -2- not shown in the illustration.
Loosen the cylinder head bolts ½ turn in sequence from 10 to 1. After that, completely unscrew the bolts in the same sequence. A - inlet side; B - release side.
With the help of an assistant, remove the cylinder head.
Attention: Do not place the removed cylinder head with the sealing surface downwards, as this can damage the glow plugs. Place the cylinder head on two wooden supports.
Installation
Attention: Machining of the sealing surface of the cylinder head is not permitted.
Lay a new cylinder head gasket dry and on a dry surface so that the bores in the cylinder head and cylinder block are not obstructed. The sealing gasket is marked with a different number of holes -arrow- depending on the thickness. The new gasket must be the same thickness (with the same number of holes), which is the removed gasket.
Note: The gaps between the chain shaft and the cylinder head do not need to be sealed with sealant. There are additional sealing strips -arrows- on the gasket in these places.
The cylinder head bolts are tightened in 5 steps. In each step, the bolts are tightened respectively in sequence from 1 to 10. A - inlet side; B - side release.
- Reception 1: Using a torque wrench, tighten the bolts to 80 Nm.
- Technique 2: Using the locked key, loosen the bolts again by 180° (½ turn).
- Reception 3: Using a torque wrench, tighten the bolts to 50 Nm.
- Technique 4: turn 90°using the locked key (¼ turn).
- Technique 5: turn 90°using the locked key (¼ turn).
Screw in and tighten to 15 Nm the bolts securing the chain shaft.
Screw in 2 new support pins with new O-rings for tensioner and guide rails. The bearing pins must be replaced as the thread is covered with a micro-shell and is therefore self-locking.
Screw the sprocket with the applied chain to the camshaft, do not overtighten the mounting bolt.
Caution: The contact surfaces of the mating parts must be free of grease and must be clean.
Remove the chain tensioner fixing pin to tension the chain. Screw the plug into the cylinder head into the locking pin hole.
Install camshafts.
Screw the coolant line with a new gasket under the thermostat housing to the cylinder head.
Screw on the cooler of the EGR system with new gaskets of the flange connections. Fit coolant hoses and secure with clamps.
Connect the hoses to the thermostat housing and secure them.
Screw turbocharger with new gasket to exhaust manifold with new self-locking nuts. Lubricate bolts with copper (high temperature) grease. Tighten nuts to 45 Nm.
Always install a new cylinder head cover gasket.
Not angular joints of the sealing surface of the cylinder head cover in the area between the cylinder head and the vacuum pump, apply a roller of Drei Bond 1209 or Loctite Ultra Black sealant with a height and width of approximately 2 mm.
First tighten the cylinder head cover bolts by hand in a crosswise manner in sequence from 22 to 1. Then tighten the bolts to 15 Nm in a second step in the same sequence.
Connect and secure the plug connector at the mass air flow meter.
Fasten the intake manifold with two bolts, see figure W-10371 above.
Install injectors and high pressure fuel lines.
Install intake manifold.
Install interchangeable engine air filter element.