- Reduced engine power.
- Low coolant level, white exhaust smoke when the engine is hot.
- Coolant in engine oil. The oil level does not decrease, but rather increases. Gray oil in the engine, foam on the oil dipstick. Oil liquefaction.
- Engine oil in the coolant, decreasing oil.
- Lack of compression in two adjacent cylinders.
Withdrawal
Unscrew the front pipe of the exhaust system.
Drain coolant.
Remove air filter (see section «Removal and installation of the air filter»).
Disconnect ground wire from battery.
Detach water hoses -G- and -H- after completely releasing and pulling the clamps. Cut the clamps with side cutters and replace them with screw clamps during installation.
Unscrew diagnostic connector -F- and lay to one side.
Unplug connector -E- for temperature switch.
Carburetor engines: Detach fuel hose -I- from mechanical fuel pump.
Disconnect connectors -J- and -K-.
Detach vacuum hose -L- from intake manifold to hydraulic brake booster.
Disconnect connector -M- from actuator motor after retracting clip -N-.
Unclip wiring harness -P- and pull out wiring harness.
Detach vacuum hoses -1-, -2-, -3- from electric switchover valve.
Disconnect all water hoses from the cylinder head.
Mark all fuel and vacuum hoses attached to the cylinder head and intake manifold with adhesive tape and disconnect.
All electrical wires suitable for the cylinder head and carburetor are marked with adhesive tape and disconnected.
Remove all spark plug tips, then the ignition wires together with the ignition distributor cap (see section «Removal and installation of the distributor of ignition»).
Disconnect the electrical wires from the ignition distributor.
Remove throttle cable (see section «Throttle cable adjustment»).
Unbolt intake manifold support.
Disconnect electrical wires from starter.
Model 318i with K-Jetronic
Loosen the oil dipstick tube support.
Clean the injection pipes on the fuel dispenser and then unscrew them. Close the ends of the tubes, as well as the fittings on the dispenser, with plugs to prevent dirt from getting in.
Disconnect the engine preheat control connector.
Vehicles with L/LE-Jetronic or Motronic
Shine connectors with injectors. On a 6-cylinder engine, disconnect the connectors from the injectors -1-, -2-, -3- and from the oil valve and route the wiring harness under the intake manifold. Disconnect connectors for auxiliary air flap from injectors -4-, -5-, -6-.
Insert the ventilation pipe and fix it in this position with BMW tool 111290.
Disconnect connector U- for air mass meter and connector -Q- for idle air control valve -R-. Open the control valve.
Detach hose -S- from intake manifold.
Release clamp -T-.
Unscrew air mass meter and remove together with air filter and control valve.
Unscrew diagnostic connector 1.
Disconnect water hoses -2-, -3-, -4-, -6-. First completely release and move back the clamps.
Detach fuel hose -7-.
Unscrew holder -8-.
Remove V-belt (see section «Removing and installing alternator V-belt. V-belt replacement»).
Raise the TDC sensor wire and pull it out together with the protective cover.
Remove cylinder head cover -E- (see section «Removal and installation of a cover of a head of cylinders»).
Unscrew cover -G- for camshaft sprocket and remove together with bracket -F-.
Attention: The cover is partially glued. Loosen the cover with gentle blows of the palms or with a plastic mallet.
Set the engine to top dead center on cylinder 1. To do this, place the gearbox in neutral, tighten the handbrake. Turn the crankshaft with a 27 mm socket with a ratchet extension on the center bolt of the crankshaft pulley in the direction of engine rotation, i.e. clockwise, until the following marks match.
The notch -F- on the belt pulley must align with the projection -E- on the timing gear cover.
The risk on the slider of the ignition distributor must match the risk on the distributor housing.
At the same time, the notch -H- on the camshaft boss must align with the notch -G- on the cylinder head.
Six-cylinder engine: do not completely remove the toothed belt from the camshaft pulley.
Remove ignition distributor (see section «Removal and installation of the distributor of ignition»).
Remove the chain tensioner piston (see section «Removing and installing, checking the chain tensioner»).
Mark the relative position of the camshaft sprockets and chain. To do this, draw a line along the chain and sprocket with a rake or apply paint on them so that during assembly the chain is installed on the sprocket in the same position.
Loosen the fixing screws (arrows). To do this, tap the wrench handle lightly to overcome the tightening torque.
Remove the camshaft sprocket.
Caution: Do not turn the crankshaft when the chain or toothed belt is removed.
Loosen the cylinder head bolts in reverse order, i.e. 10-1. On a six-cylinder engine, unscrew the cylinder head bolts 14-1 in the same sequence. as on a four-cylinder engine.
Remove cylinder head.
Attention: After removal, do not place the cylinder head on the contact surface, as this may damage the open valves. Therefore, put the cylinder head on two wooden spacers.
Installation
Before installing, clean the cylinder head and cylinder block from the remnants of the old seal. Do not allow seal residues to enter cylinder bores.
Close the cylinder bores with rags.
Measure the flatness of the cylinder head and engine block with a steel ruler in the longitudinal and transverse directions and. if required, mill (service station work). If the cylinder head is milled, the camshaft sprocket cover must also be milled to the same size.
Check the cylinder head for cracks and the cylinder sliding surfaces for scratches.
Thoroughly clean the cylinder head bolt holes of oil and other residues.
Attention: There must be no oil in the recesses, otherwise the bolts will not fully tighten the cylinder head, despite the fact that they are tightened to the required torque. In addition, it can break the motor block.
Be sure to replace the cylinder head gasket.
Apply a new gasket without sealing compound so that it does not block the holes.
Attention: With a milled cylinder head, a cylinder head gasket of normal thickness or 0.3 mm more may be installed, depending on the height of the modified cylinder head. By installing a thicker gasket, a decrease in the volume of the combustion chambers is prevented.
Before installing the cylinder head, check that the camshaft is at top dead center.
Install the cylinder head.
Be sure to replace and lightly lubricate the cylinder head bolts with engine oil. On six-cylinder engines manufactured from September 1987, install only hexagon socket head bolts.
Insert and tighten the cylinder head bolts by hand. 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 the HAZET 6690, is required to tighten the cylinder head bolts.
Attention: On each pass, tighten the cylinder head bolts in the sequence 1-10, on a six-cylinder engine - 1-14.
M10 four-cylinder engine
On the 1st pass, tighten the cylinder head bolts with a torque wrench to a tightening torque of 60 Nm. After that, pause for about 15 minutes for the bolts to settle.
On the 2nd pass, tighten the head bolts with a hard wrench at an angle of 33±3°.
Six-cylinder engine
On the 1st pass, tighten the cylinder head bolts with a torque wrench to a tightening torque of 40-45 Nm. After that, pause for about 15 minutes for the bolts to settle.
On the 2nd pass, tighten the cylinder head bolts with a torque wrench to a tightening torque of 50-65 Nm.
Six-cylinder engine from September 1987 with cylinder head bolts with hexagon sockets:
- 1st pass - tightening with a torque wrench to a torque of 30 nm.
- 2nd pass - tighten with a hard wrench at an angle of 90°.
- 3rd pass - tighten with a hard wrench at an angle of 90°. Attention: Pause between individual passes, it is not necessary to warm up the engine.
Check chain engagement with crankshaft sprocket teeth. Check that the camshaft and crankshaft sprockets are at top dead center.
Insert the sprocket into the chain like this. to match the marks made when removing the mark. The hole for the locking pin must be at the bottom.
Slide the sprocket onto the camshaft and secure with a tightening torque of 7 Nm.
Install the chain tensioner piston (see section «Removing and installing, checking the chain tensioner»).
Place the toothed belt on the camshaft pulley and tighten (see section «Removal and installation of a gear belt»).
Re-check that the camshaft and crankshaft are at top dead center.
Attention: The marks must match in the same way as when removing, otherwise pistons and / or valves may be damaged when turning the engine.
Install the ignition distributor, connect the ignition wires (see section «Removal and installation of the distributor of ignition»).
Screw the camshaft sprocket cover together with the air filter housing bracket. Pre-fill holes (arrows) on the left and right in the cylinder head gasket with a liquid universal sealant, e.g. Curil. After that, glue a new cover gasket with a small amount of grease. Install the cover and first tighten the lower bolts slightly. Screw in and tighten the remaining bolts to the required torque, then tighten both lower bolts. Tightening torque: M6 bolts - 10 Nm, M8 bolts - 22 Nm.
Adjust valve clearances (see section «Checking and adjusting valve clearances»).
Install cylinder head cover (see section «Removal and installation of a cover of a head of cylinders»).
Model 318i with K-Jetronic
Tighten the guide tube of the oil dipstick.
Screw the fuel injection pipes to the fuel dispenser.
Connect the connector to the engine warm-up regulator.
Vehicles with L/LE-Jetronic or Motronic
Screw the bracket to the intake manifold.
Connect fuel hose to pressure regulator and secure with hose clamps.
Screw on diagnostic connector.
Connect and clamp all water hoses to the coolant regulator housing.
Install spark plugs (see section «Spark plug»).
Insert TDC sensor cable with protective cover.
Install and tighten V-belt (see section «Removing and installing alternator V-belt. V-belt replacement»).
Check the O-ring of the ventilation hose for cracks and damage and replace it if necessary. Remove BMW tool 111209 and make sure that the ventilation hose returns to its original position.
Insert and screw down the air filter housing together with the air mass meter and idle air control valve. Connect electrical wires.
Screw on intake manifold support.
Install and tighten V-belt (see section «Removing and installing alternator V-belt. V-belt replacement»),
Connect and clamp all water, fuel and vacuum hoses.
Connect all electrical wires as marked.
Install and adjust the throttle cable.
Secure the wiring harness to the cylinder head with clips.
Screw on diagnostic connector.
Screw the front exhaust pipe to the exhaust manifold.
Connect ground wire to battery.
Install air filter (see section «Removal and installation of the air filter»).
Fill the cooling system with coolant (see section «Coolant replacement»).
Check engine oil level. If the cylinder head was removed due to a defective gasket, it is recommended to change the engine oil with the replacement of the oil filter, since coolant could have entered the oil.
Check and, if necessary, adjust the ignition timing.
Start the engine and warm it up for 25 minutes.
Remove cylinder head cover (see section «Removal and installation of a cover of a head of cylinders»).
Engines with cylinder head bolts with hexagon sockets: Tighten all cylinder head bolts in sequence 1 - 10 (on a six-cylinder engine - 1-14) with a hard key at 25-30°.
Attention: On engines with cylinder head bolts with hexagon sockets, the bolts are not additionally tightened.
Install cylinder head cover (see section «Removal and installation of a cover of a head of cylinders»).
Check and, if necessary, adjust the idle speed and CO content (see section «Ignition timing, CO content, idle speed»).
Note: The cylinder head bolts do not need to be tightened after 1000 km.
Cylinder Head Bolt Torque for 324d/td:
- 1st pass - tightening with a torque wrench up to 50-60 nm.
- 2nd pass — tighten the bolts in sequence 1—10 by 90±5°, bolts 11—14 by an angle of 73±3° (see W-1097). 15 minutes to warm up the engine.
- 3rd pass - tightening with a rigid wrench at an angle of 90±5°.