Range Rover P38
BMW DIESEL
33
REPAIR
28. Dry ream valve guides using BMW tool 004210
and appropriate size reamer from those supplied
with tool.
29. Ream valve guide from combustion chamber
side, rotate tool once only in a downwards
direction; remove all traces of swarf on
completion.
Check valve head stand-down
30.
Original valves: Lap valves to their seats,
remove all traces of grinding paste on
completion.
31.
Replacement valves: Do not lap valves to their
seats.
32. Insert No.1 valve into its guide.
33. Position suitable DTI to cylinder head, pre-load
then zero gauge.
34. Position DTI to centre of valve, measure valve
head stand-down and compare with figures
given:
Inlet = 0.65 to 0.85 mm (0.02 to 0.03 in)
Exhaust = 0.85 to 1.05 mm (0.03 to 0.04 in)
35. Replace any valve having stand-down in excess
of figures given with a valve having an increased
head thickness.
36. Refer to the following to determine thickness of
valve head required ensuring that valves with
correct size stem diameter are obtained.
NOTE: It will be necessary to re-cut valve
seats when fitting valves with increased
head thickness.
Standard valve stem diameter:
Head thickness increase - 0.25 mm (0.01 in)
Identification marks - RO
