Checking valve clearance at two crankshaft positions
1. Check TDC position of piston in cylinder 1 bank A:
• If rocker arms on cylinder 1 bank A are unloaded, the piston is in firing TDC.
• If rocker arms on cylinder 1 bank A are loaded, the piston is in overlap TDC.
2. Check valve clearance with cold engine:
• Inlet (I) = 0.3 mm;
• Exhaust (X) = 0.4 mm.
3. Check all valve clearances at two crankshaft positions (firing TDC and overlap TDC) according to the table
below.
Position Cylinder 1 2 3 4 5 6 7 8 9 10
12V
Firing TDC in cylinder A1 Bank A I X I – – X I – – X – –
Bank B I – – – – X I – I X – X
Overlap TDC in cylinder A1 Bank A – – – X I – – X I – I X
Bank B – X I X I – – X – – I –
16V
Firing TDC in cylinder A1 Bank A I X – X – X I – – X I – – – – –
Bank B I – – X – – I – I X I – I X – X
Overlap TDC in cylinder A1 Bank A – – I – I – – X I – – X I X I X
Bank B – X I – I X – X – – – X – – I –
I
Inlet: Inlet valve adjustment admissible
X
Exhaust: Exhaust valve adjustment admissible
–
Valve adjustment inadmissible
4. Check gap between valve bridge and rocker arm with valve clearance gage.
5. If the deviation from the specified value exceeds 0.1 mm, adjust valve clearance.
Adjusting valve clearance
1. Undo locknut (1) and unscrew adjusting
screw (2) by a few turns.
2. Insert valve clearance gage (3) between valve
bridge and rocker arm.
3. Turn adjusting screw (2) so that valve clear-
ance gage (3) just passes through the gap.
4. Tighten locknut (1) with torque wrench to the specified tightening torque, holding the adjusting screw (2)
with Allen key to prevent it from turning.
Name Size Type Lubricant Value/Standard
Locknut M12x1 Tightening torque (Engine oil) 50 Nm
5. Check that valve clearance gage (3) just passes through between valve bridge and rocker arm.
Result: If not, adjust valve clearance.
M015650/06E 2018-05
| Valve Drive | 109
TIM-ID: 0000050016 - 003
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