MTU 20 V 4000 G23, Technical Publication

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Task Description 103
Diagram
• Two crankshaft positions
• Applicable to 16V engines
1 Cylinder A1 is in firing TDC
2 Cylinder A1 is in overlap TDC
I Inlet valve
X Exhaust valve
Diagram
• Two crankshaft positions
• Applicable to 20V engines
Checking valve clearance at two crankshaft positions
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 loaded on cylinder A1, the piston is in overlap TDC.
2. Check valve clearance with cold engine:
• Inlet valves (long rocker arm) = 0.2 mm
• Exhaust valves (short rocker arm) = 0.5 mm
3. Check all valve clearances at two crankshaft positions (firing and overlap TDC for cylinder A1) as per diagram.
4. Use feeler gauge to determine the distance between valve bridge and rocker arm.
5. If the deviation from the reference value exceeds 0.1 mm, adjust valve clearance.
M015715/00E 06-08 © MTU