| Remove cylinder head |
| Remove spark plugs |
| Mount cylinder head on an appropriate stand |
| Install a valve spring compressor on the valve, compress the spring,
remove the retainers (green arrow), release the valve springs and remove the valve. |
 |
| All valves must be kept in order and returned to the same
position when reassembled. |
| Remove valve stem seals with BMW special tool 11 1 250 or equivalent
pliers. Pliers should have a rounded head so as to prevent crushing the valve guides. |
|
| Lift off valve spring seats. Failure to lift these off now will result in
them falling off during valve lapping procedure, which could lead to loss or damage of
seats. |
 |
Installation
|
| Check valve guides for wear |
| Place head upside down and apply a small amount of valve
grinding compound to the seating surface of the valve. Place the valve in the guide,
use a readily available "valve lapper" to spin the valve in the guide. Use a
rubbing motion with the lapper between your hands so the lapper is constantly
changing direction. Every 2 or 3 strokes, rotate the valve an extra 1/4 turn so that the
mating surfaces are being properly and evenly ground. Remove valve and clean it and
the seat. |
CAUTION: It is very easy to get confused after you turn the head upside down and lap the
valves into the wrong cylinders. When disassembling the head, place the valves on a
numbered board or piece of cardboard. Take note of the orientation of the now upside down
head , and apply the correct valves to each cylinder.
|
| Lubricate valve stem with engine oil and insert in guide. Clean
spring seats and place on cylinder head (arrow) |
|
| Place plastic tube included in valve seal set over valve stem and slide
valve stem seal over valve and onto the guide. |
 |
| Press the seal onto the guide with BMW special tool 11 1 200 or an
equivalent tool. Valve seal should be installed evenly and to the stop. If possible,
obtain a tool specifically designed for pressing on valve stem seals, install seals by
hand, do not use a hammer on the tool to seat the seal. |
 |
| Place springs over valves. Install caps on springs. Compress springs and
install retainers. Placing the retainers is made easier by dabbing grease on the inner
surface. The grease helps hold it in place on the valve stem while you release the spring.
A grease covered screw driver is a simple, yet effective, tool for installing the
retainers. |
 |
| Note
: It is recommended to replace the valve spring caps and retainers. These items are cheap
and can cause disastrous damage if they fail. |
| Re-install cylinder head |
|
| Adjust valves. |
|
