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 (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 I 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 I X – – – X – – I –
I
Inlet: Inlet valve adjustment admissible
X
eXhaust: Exhaust valve adjustment admissible
–
Valve adjustment inadmissible
4. Use feeler gage 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.
Adjusting valve clearance
1. Loosen locknut (1) and unscrew adjusting
screw (2) by a few threads.
2. Insert feeler gage (3) between valve bridge
and rocker arm.
3. Readjust adjusting screw (2) so that the
feeler gage (3) just passes through the gap.
4. Tighten locknut (1) to the specified tighten-
ing torque of 50 Nm using a torque wrench
while holding the adjusting screw (2) with
an Allen key.
5. Check that the feeler gage (3) just passes
through between valve bridge and rocker
arm.
Result: If not, adjust valve clearance.
Final steps
1. Remove barring gear.
2. Install cylinder head cover (→ Page 91).
3. Install air filter (→ Page 107).
90 | Task Description |
M015650/05E 2014-03
TIM-ID: 0000050016 - 001
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