Checking valve clearance at two crankshaft positions
1.
Check TDC position of piston in cylinder A1:
• If the rocker arms are unloaded on cylinder 1, bank A, the piston is in firing TDC.
• If the rocker arms are loaded on cylinder 1, bank A, 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
8V
Firing TDC in cylinder A1
Bank A
I X – X I – – X
Bank B
I –
I –
– – – X
Overlap TDC in cylinder A1
Bank A
– –
I – – X I –
Bank B
– X – X I X
I –
10V
Firing TDC in cylinder A1
Bank A
I X – – – – – X I –
Bank B
I –
– – – X I X
I –
Overlap TDC in cylinder A1
Bank A
– – I X
I X
I – – X
Bank B
– X I X
I –
– – – X
I
Inlet: Inlet valve adjustment admissible
X
Exhaust: Exhaust valve adjustment admissible
–
Valve adjustment inadmissible
4.
Use valve clearance 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.
Adjusting valve clearance
1.
Loosen locknut (1) and unscrew adjusting
screw (2) by a few threads.
2.
Insert valve clearance gauge (3) between
valve bridge and rocker arm.
3.
Readjust adjusting screw (2) so that the valve
clearance gauge (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
MS150060/04E 2016-02
| Valve Drive | 81
TIM-ID: 0000050015 - 003
