Valve Guide: Testing and Inspection

WM 157502 Checking valve guide (valve lateral play)

Tools





Preliminary work

CAUTION

Risk of damage due to particles of dirt.

- Danger of material damage due to blocked oil bores/oil ducts.

-> Absolute cleanliness is essential when working on the engine.
-> Lay removed engine parts on a clean base and make sure to cover them.
-> Use the cover for dust protection when fitting the engine NR.165 on the engine assembly support.

CAUTION

Incorrect tray.

- Damaged and scratched sealing face.

-> Work on cylinder head only on a clean surface on the work bench.

1. Remove cylinder head -> 157019 Removing and installing cylinder head - section on "Removing" 157019 Removing and installing cylinder head.
2. Disassemble cylinder head and clean components -> 157037 Disassembling and assembling cylinder head - section on "Disassembling" 15703750 Disassembling and assembling cylinder head.

Checking valve guide (valve lateral play)

Special tool retaining device 9739





Tool for fixing valve position

1. Fit special tool retaining device 9739 in cylinder head (valve stem side). To do this, screw in the fastening screws by hand into the spark plug thread.





Special tool 9739 fitted

Information

The permitted valve tilt play is 0.25 mm.

2. Check valve tilt play on intake valve. Adjust the dial gauge to the relevant angle of the valve to be checked and set to '0' with preload. Press valve disc towards dial gauge and pull it back again. Read off value and note it.





Checking valve tilt play of intake valve

3. Check valve tilt play on exhaust valve. Adjust the dial gauge to the relevant angle of the valve to be checked and set to '0' with preload. Press valve disc towards dial gauge and pull it back again. Read off value and note it.





Checking valve tilt play on exhaust valve

4. Check all valves.

Subsequent work

1. When all valve guides are within the permitted tolerances, assemble cylinder head again. If the specification is exceeded, the cylinder head must be replaced.
2. Install cylinder head -> 157019 Removing and installing side cylinder head - section on "Installing" 157019 Removing and installing cylinder head.