Withdrawal
Disconnect the ground wire from the battery.
Attention: When the battery is disconnected, the information in the electronic memory devices, such as the engine trouble memory or the radio security code memory, is erased. When disconnecting the battery, follow the instructions in sections "Radio" And "Removing and installing the battery".
Drain the coolant from the engine by unscrewing the drain plug on the side of the engine block under the exhaust manifold. After draining, immediately screw on the plug and tighten it.
Loosen the intake manifold mounting bolts and remove the mounting.
Release the following hoses from the mounts on the cylinder head: 1 - vacuum hose of the brake booster; 2 - heater water hose; 3 - fuel hose to the high pressure fuel pump.
Disconnect the vacuum hose from the intake port (at the EGR valve).
Disconnect the intake manifold temperature sensor connector by depressing the wire clip.
Open intake manifold.
Loosen the union nuts of the injection pipes on the injectors and on the high pressure fuel pump. This requires a special BMW key or HAZET key no. 4550. Seal the holes with plugs.
Disconnect wires from glow plugs.
Remove V-belt.
Unscrew the front muffler pipe from the turbocharger. On a four-cylinder engine, unscrew the turbocharger from the front muffler pipe.
Loosen the cylinder head bolts first ½ turn and then back out. There are only 6 bolts on a four-cylinder engine. Remove cylinder head cover.
Unscrew the hydraulic V-belt tensioner and disconnect the damper. Attention: Store the removed tensioner only in the installation position, i.e. standing up. Otherwise, there may be violations in its work.
Remove 2 screws and remove vacuum pump. Bolt -2- also serves to fasten the guide chain. Since the thread of the bolt must be covered with a seal, cover the thread of the new bolt with a sealing compound. After each loosening, the bolt is either replaced or covered with a conventional liquid sealing mass.
Set the engine to the top dead center of cylinder 1. To do this, engage 5th gear and move the vehicle forward on level ground or turn the crankshaft pulley in the direction of engine rotation until the camshafts of the intake and exhaust valves of the first cylinder (from the drive chain) will be directed towards each other.
Lock the crankshaft at top dead center with BMW 11 2 300 or another suitable rod. To do this, insert the rod through the hole in the engine block into the hole in the flywheel.
Secure camshaft with BMW tool. Unscrewing the camshaft sprocket can be dispensed with without a tool by holding the camshaft by a 27 mm hexagon.
Insert a chain tensioner bar suitable for the clamping lever and press the tensioner.
Unscrew the plug and fix the tensioner in the compressed state with the corresponding rod.
Unscrew tensioner retaining pin from cylinder head and remove O-ring.
Loosen the gear box cover bolts. Fastening -1- is made in the form of a stud and a nut.
Unscrew bolt -arrow- and disconnect drain hose from injector.
Ansaugkrummer - intake manifold
Abgaskrummer - intake manifold
In sequence 14 to 1, first loosen the cylinder head bolts ½ turn and then back out. To loosen the cylinder head bolts, an E12 Torx head bolt wrench is required.
Remove cylinder head.
Attention: After removal, do not place the cylinder head on the contact surface, otherwise fully open valves may be damaged. Therefore, the cylinder head should be placed on 2 wooden blocks.
Installation
Before installing, clean the cylinder head and engine block from seal residues. Residues of seals must not fall into the holes, cover the holes with rags. Check position of dowel sleeves -arrows-.
Measure the flatness of the cylinder head and engine block with a steel ruler in the longitudinal and transverse directions. Attention: The cylinder head cannot be milled. When noted, it should be replaced. Check the cylinder head for cracks and its running surfaces for scratches.
Thoroughly clean the holes for the cylinder head bolts from oil and other objects.
Attention: There must be no oil in the recesses, otherwise the bolts will not completely tighten the cylinder head, despite the fact that they are tightened to the required torque. In addition, the motor block may crack.
Be sure to replace the cylinder head gasket.
Lubricate the joints of the gear box cover with the cylinder head with a sealing mass "Drei Bond 1209".
Apply a new gasket without sealing compound so that it does not block the holes. The gasket, depending on its thickness, has a different number of marking holes. The new gasket must be the same thickness (the same number of marking holes), which is the removed gasket.
If it is not clear which gasket to install, for example after repairing the engine block, measure the piston protrusions. The thickness of the gasket is selected according to the maximum protrusion of one of the 6 pistons. To measure, put a dial gauge at point -A- and, with a slight crankshaft rotation in both directions, determine the highest position. After that, repeat the measurement at point -B-. The average value between the measurement results at points -A- and -B- gives the value "piston protrusion". These measurements should be carried out on all 4 or 6 pistons respectively.
Based on 6 results, the average value is determined. That is, you should add all the results and divide the sum by 4 or 6 respectively. If you get a value of less than 0.76 mm, you should install a gasket with 2 holes. Above 0.76mm, a 3-hole gasket is installed.
Caution: However, if one or more cylinders have a piston protrusion greater than 0.81 mm, a 3-hole gasket is installed.
Install the cylinder head.
Attention: After removing the head, do not turn the camshaft and crankshaft, otherwise, during installation, the open valves will abut against the pistons. The illustration shows the high pressure fuel pump sprocket. The label must be facing up.
Insert and hand tighten the cylinder head bolts lubricated with engine oil.
Caution: Be very careful when tightening the cylinder head bolts. Before tightening the bolts, check the accuracy of the torque wrench. In addition, a protractor, such as HAZET 6690, is required to tighten the cylinder head bolts. If a protractor is not available, place the key on the bolt head, attach a square to the key handle and mark the desired angle with chalk. Subsequently, turn the key handle in one pass to the line marked with chalk.
Four cylinder diesel engine:
Six-cylinder engine (Drawing W 1097):
The cylinder head bolts are tightened in 6 passes. On each pass, tightening is performed in sequence from 1 to (Four-cylinder engine: 1 to 10)
- 1st pass: tighten with a torque wrench of 80 Nm.
- 2nd pass: tighten with a hard wrench 180°and then loosen the bolts.
- 3rd pass: torque wrench tightening from 50 Nm.
- 4th pass: hard wrench tightening 90°.
- 5th pass: hard wrench tightening 90°. After 25 minutes of engine operation (after installing it):
- 6th pass: 90°hard wrench tightening.
Replace the seal on the high pressure fuel pump spore. Apply at the junction with the box cover» gears elastic sealing mass, e.g "3 Bond 1209".
Install the gear box cover, tighten the bolts to 10 Nm.
Tighten the fasteners next to the nozzle, and also put the return fuel hose on the nozzle (Drawing W 10254).
Screw in the 2 retaining pins of the tensioning bar and chain guide with new O-rings.
Screw the sprocket with the applied chain to the camshaft, do not tighten the bolt yet.
Attention: The contact surfaces must be degreased and clean.
Remove the blocking rod from the chain tensioner so that the chain is tensioned. Screw the plug into the hole in the cylinder head.
Only if the camshaft is blocked using the BMW adjustment template: The template is suitable for adjusting chains up to approx. 20,000 km. For chains with high mileage, a gasket must be installed on the side of the intake valves of the cylinder head (probe) thickness A=4.61 mm. If a template is not used, turn the camshaft approx. 2 to the left and hold it in this position with a 27 mm hexagon.
In this position, tighten the camshaft sprocket in 2 passes:
- 1st pass: with a torque wrench until the tightening torque is 20 Nm;
- 2nd pass: hard wrench tightening 35°.
Caution: Remove the flywheel and crankshaft locking tools and camshaft. Crank the engine several times by hand and check the valve timing again.
Insert the vacuum pump in place with the O-ring, the driver must engage with the cutout in the camshaft sprocket.
Caution: The Torx head bolt on the camshaft sprocket has a hole for vacuum pump lubrication. Clear the hole of dirt.
Tighten the 2 vacuum pump bolts to 20 Nm. Either replace the inner bolt with a new one or cover it with a conventional liquid sealing mass.
Insert shock absorber and V-belt tensioner bracket and screw down.
Install V-belt.
Check the integrity of the cylinder head cover gasket and replace if necessary.
Fit cylinder head cover and tighten bolts crosswise from inside to outside to 15 Nm. In doing so, ensure that the gasket is correctly positioned in the cutouts, see illustration.
Six-cylinder engine: Screw front muffler pipe with new gasket with new self-locking nuts to turbocharger. Pre-coat bolts with copper (high temperature) paste. First tighten all bolts to a tightening torque of 30 Nm, then tighten them to a torque of 50 Nm. For the version with compression springs, tighten the nuts to a spring length of 27 mm.
Four-cylinder engine: Screw the turbocharger with a new gasket with new self-locking nuts to the front muffler pipe. Pre-coat bolts with copper (high temperature) paste. Tighten all bolts to a tightening torque of 45 Nm
Connect wires to glow plugs. Push the connectors until they click into place.
Insert the injection pipes without bending them. Tighten the union nuts with a special wrench to a torque of 20 Nm.
Replace intake manifold gaskets. After that, install the intake manifold, tighten the bolts crosswise to a torque of 25 Nm.
Tighten the intake manifold mounting bolts.
Route all hoses in the mounting on the intake manifold and connect them.
Connect electrical wires.
Connect ground wire to battery.
Fill with coolant.
Check engine oil level, top up if necessary. If the cylinder head was removed to replace a blown cylinder head gasket, it is recommended to change the oil with an oil filter change, as coolant may have entered the oil.
Attention: Warm up the engine for 25 minutes, remove the cylinder head cover and tighten the cylinder head bolts according to the instructions above.
Install the cylinder head cover and tighten the bolts crosswise in sequence from the inside to the outside to a torque of 15 Nm.