Measuring valve depth
1.
Check TDC position of piston in cylinder A1:
• If the rocker arms are unloaded on cylinder A1, the piston is in firing TDC.
• If the rocker arms are under load on cylinder A1, the piston is in overlap TDC.
2.
Measure valve depth for each valve in two crankshaft positions (firing TDC and overlap TDC for cylinder
A1) according to the diagram. Diagram (→ Page 148).
3.
Release adjusting screw (1) and remove
valve bridge. Do not remove rocker arm (2)!
4.
Measure distance between valve stem end
and cylinder head top at the spark plug
bore with depth gauge (see figure).
• The specified value for a new cylinder
head: 93.8 mm.
• Admissible wear: 3 mm.
• If the measured value is > 96.8 mm, re‐
place the relevant cylinder head ahead of
schedule (→ Instructions for Overhaul of
Assemblies).
5.
Install valve bridge.
6.
Adjust valve clearance (→ Page 148)
Final steps
1.
Remove barring device (→ Page 133).
2.
Check condition of O-rings at the sleeves, replace if damaged.
146 | Task Description | MS150033/04E 2012-07
TIM-ID: 0000012015 - 002
