Disassembling the cylinder head (BMW 3 Series E21)

Install the cylinder head on support 11 12 100.

Remove the central oil line.

Remove the camshaft timing pulley.

Set the rocker arms of the intake and exhaust valves of all cylinders to the position corresponding to the largest clearance between the rocker arm eccentric and the end of the valve stem.

Remove the plugs from the ends of the rocker arm shafts.

Remove the rocker arm shaft guide flange and take out the rocker arm spring retainers.





Install the washer and sleeve to rotate the camshaft.



Make sure that the valves of the 6th cylinder are overlapped and move the valve rocker arm of the 1st cylinder away from the front end of the cylinder head.

Turn the camshaft in the intake direction until the rocker arms of all intake and exhaust valves are suspended.

Remove the intake rocker arm shaft.

Turn the camshaft in the exhaust direction until the rocker arms of all intake and exhaust valves are suspended.

Remove the exhaust rocker arm shaft.

Check the condition of the rocker arms, the degree of wear of the rubbing parts and the rocker arm adjusting eccentrics. Replace damaged and faulty parts.

When installing a new rocker arm, point the flat surface of the adjusting eccentric bolt toward the back of the rocker arm.

Screw the spark plugs into the cylinder head sockets and turn the cylinder head over.

Fill the combustion chambers with fuel and check the valves for leaks.

Install support plate 111066 on valve spring compressor tool 111060.



Release the valves from the crackers by compressing the valve springs with tool 111060. Remove the springs with the plates: take out the valves.

Remove the valve stem seals from the valve guides.

Replacing valve guide bushings

Press out the valve guide on a cold engine using tool 111330, pushing the guide from the top of the cylinder head towards the combustion chamber.

Check the valve guide bushing seat dimensions in the cylinder head. If the valve guide bushing seat diameter is larger than the permissible value, bore the seat to the nearest repair size and press in a valve bushing of the corresponding repair size.

Heat the cylinder head evenly to a temperature of 220–250°C.

Working from above the cylinder head, press the valve sleeve into the cylinder head seat using mandrel 11 1 320, the hole of which determines the pressing depth of the valve sleeve.

Grinding of valve seats and valves

Grind the valves, maintaining the height of the valve head edge, which should be at least 1.2 mm, and the working chamfer angle, which should be within 44°30'—20'.

Grind the valve seats and lap the valves.

Check the valves for leaks as described above.

(This publication was borrowed from an online resource: «BMWMan.ru»)