Cylinder Head Remove and Install

REMOVING CYLINDER HEAD




- Unscrew exhaust pipes on exhaust manifolds and pipe clamp on transmission.

Installation Note:
- Check gaskets, replacing if necessary.
- Coat studs with copper paste.
- Replace self-locking nuts. Tightening torque = 50 Nm (36 ft. lbs.).




- Unscrew plug and drain coolant.

CAUTION: Disconnecting the battery will cancel (clear) the memory of control units which have diagnostic trouble code capabilities. Be sure to interrogate all control units for possible diagnostic trouble codes prior to disconnecting the battery.
BMW anti-theft radios can be rendered useless by disconnecting the battery. Make sure you know the correct code before disconnecting the battery. See your owner's manual for more information.

- Disconnect battery ground lead.

Installation Note:
- Torque coolant drain plug to 50 + 6 Nm (37 + 4 ft lb).
- Fill cooling system with coolant.
- Replace engine oil.




- Disconnect throttle cable (1) and cruise control cable (2).

Installation Note:
- Adjust throttle cable.
- Adjust cruise control cable.

- Disconnect throttle pressure cable (Kickdown Cable) (3).

Installation Note: Adjust throttle pressure cable (3).




- Pull off vacuum hose (4) and hoses (5).
- Pull off plugs (7 and 11).
- Pull out Hose (8) and loosen strap (9).
- Unscrew nuts (10) and remove air cleaner with air flow sensor.




- Disconnect diagnosis plug (1).
- Disconnect radiator hoses (2 ... 5).
- Pull off fuel line (6).
- Unscrew holder (7).




- Unscrew holder (8).
- Disconnect hose (9).




- Press vent tube down and hold down with Special Tool 11 1 290.

Installation Note:
- Check seal, replacing if necessary.
- Check vent tube for correct fit after removing Special Tool 11 1 290.




- Pull off hoses (10).
- Unscrew fuel lines (11 and 12).
- Unscrew holder (13).
- Pull off plugs on fuel injectors 4, 5 and 6.
- Pull off plugs (14 and 15).

Installation Note: Use new squeeze hose clamps.




- Pull off plugs on fuel injectors 1, 2 and 3.
- Pull off plugs (5 ... 8).
- Pull off wire (4) and disconnect ignition coil.
- Pull off wire (9) on solenoid and wires on oil pressure switch.
- Disconnect wire harness and pull out to the left side.




- Pull off spark plug end caps and unscrew ignition lead tube (10).
- Disconnect vent hose (11).
- Unscrew holder (12).
- Unscrew nuts (1 ... 8) and take off cylinder head cover.

Installation Note:
- Check gasket, replacing if necessary.
- Tighten nuts in order of 1 through 8.
6 mm 10 Nm (7 ft lb).
7 mm 15 Nm (11 ft lb).




- Turn crankshaft to set cylinder no. 1 to TDC; valves of cylinder no. 6 overlap.
- Remove distributor cap.




- Remove distributor rotor.
- Unscrew adapter (12).
- Remove cover (13).
- Unscrew bolts (14).
- Unscrew nut (15).
- Remove guard (16).

Installation Note:
- Screw on holder (17).
- Check rubber ring (18).
- Insert rubber cover (19).




- Loosen bolts (7 and 8), remove toothed drive belt, refer to Timing Belt, Service and Repair.

CAUTION: Never crank engine after removing drive belt.

Installation Note: Install new drive belt.




Installation Note: Before installing the cylinder head, turn the camshaft that mark on camshaft sprocket is facing mark on cylinder head. Cylinder no. 1 is in TDC. Also install the drive belt in this position.




- Unscrew bolts in order of 14 through 1 and remove cylinder head.

INSTALLING CYLINDER HEAD:

NOTE:
An improved cylinder head bolt has been introduced for use in the M20 engine. The new head bolt, designated ASA 14, is grade 10.9 and is identified by the Torx head and a black surface finish. Whenever engine repairs necessitate cylinder head removal, all 14 old style head bolts should be replaced with the ASA 14 bolts. Further, in instances of head bolt damage (e.g. head broken off), all 14 head bolts should be replaced one by one without removing the cylinder head. The waiting and running time requirements are no longer used.

The new ASA 14 head bolt has revised expansion properties which require new torque angle values.
Step 1 - Torque all bolts to 30 Nm (22 ft.lbs.).
Step 2 - Torque angle all bolts 90°.
Step 3 - Torque angle all bolts 90°.

CAUTION: Under no circumstances should the old and new head bolts be mixed in one engine. Remove oil and debris from bolt holes. If not, improper values or damage may result.

- Clean sealing surfaces.
- Fit cylinder head gasket in position, Cylinder Head Gasket, Replace.
- Install new, lightly oiled bolts. Use special tool 11 2 110 or 00 9 120 in the torqueing sequence 1...14.
- Reinstall all auxiliary components in reverse order of disassembly, paying close attention to installation notes and torque specs.
- Adjust valve clearance, refer to Valve, Intake/Exhaust,Valve Clearance.
- Check ignition timing.
- Check engine idle speed and CO level.

NOTE: Cylinder head need not be tightened again after driving car 1,000km (600 miles).