Range Rover. Manual — part 35
BMW DIESEL
31
REPAIR
9. Position tool LRT-12-034 on valve.
10. Compress valve spring.
11. Remove 2 collets using a stick magnet.
12. Release tool LRT-12-034, collect valve spring
cup, valve spring and spring seat, discard valve
spring.
13. Remove valve stem oil seal using LRT-12-071,
discard seal.
14. Remove valve.
CAUTION: Store valve components in their
fitted order.
15. Repeat above procedures for remaining valves.
16. Clean all components.
12
ENGINE
NEW RANGE ROVER
32
REPAIR
Inspection
Valves
17. Remove carbon from valves, valve guides and
seats.
18. Check valves for signs of burning, cracking and
pitting of valve seats.
19. Check head diameter of each valve:
Inlet = 36.0 mm (1.42 in)
Exhaust = 31.0 mm (1.22 in)
20. Check stem diameter of each valve, half-way
along stem and compare diameters with
dimensions given to determine stem sizes of
valves fitted and valve stem wear.
Standard:
Inlet = 6.97 mm (0.274 in)
Service limit = 6.95 mm (0.273 in)
Exhaust = 6.95 mm (0.273 in)
Service limit = 6.93 mm (0.272 in)
1st oversize:
Inlet = 7.07 mm (0.28 in)
Service limit = 7.05 mm (0.277 in)
Exhaust = 7.06 mm (0.278 in)
Service limit = 7.04 mm (0.27 in)
2nd oversize:
Inlet = 7.17 mm (0.282 in)
Service limit = 7.15 mm (0.28 in)
Exhaust = 7.16 mm (0.281 in)
Service limit = 7.14 mm (0.279 in)
21. If valve stems are worn in excess of service
limits, valves with next oversize stems must be
fitted and valve guides reamed to correct size.
Valve guides
CAUTION: Prior to checking/reaming valve
guides, check cylinder head for warping.
See Cylinder head gasket.
22. Position a suitable DTI to cylinder head adjacent
to No.1 valve seat.
23. Insert a new valve with same stem diameter as
the original in the valve guide.
24. Position end of valve stem flush with spring end
of guide.
25. Move valve away from DTI, pre-load gauge and
note pre-load reading.
26. Move valve towards DTI, note gauge reading
and subtract pre-load from this figure. Compare
final figure obtained with tilt figure:
Valve tilt - inlet and exhaust = 0.5 mm (0.02 in).
27. If tilt figure exceeds above dimension, original
valve must be replaced with next oversize valve
and valve guide reamed to next oversize.
Valve guide inside diameter - inlet and exhaust:
Standard = 7.0 mm (0.275 in)
For 1st oversize valve stem = 7.1 mm (0.28 in)
For 2nd oversize valve stem = 7.2 mm (0.283 in)
NOTE: Valve guides may not be replaced.
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
12
ENGINE
NEW RANGE ROVER
34
REPAIR
1st oversize valve stem:
Head thickness increase - 0.25 mm (0.01 in)
Identification marks - R1
Head thickness increase - 0.50 mm (0.02 in)
Identification marks - R2
2nd oversize stem:
Head thickness increase - 0.50 mm (0.02 in)
Identification marks - R3
NOTE: Identification marks will be found
adjacent to cotter grooves.
Valve seat - recut
37. Recut valve seats using BMW tool 003520.
Head thickness:
0.25 mm (0.01 in) - Increase depth by 0.25 mm
(0.01 in)
0.50 mm (0.02 in) - Increase depth by 0.50 mm
(0.02 in)
38. Use BMW tool 003580 to obtain specified valve
seat dimensions:
Valve seat angle A = 45
° ±
10’
Correction angle - outside B = 15
°
Correction angle - inside C = 60
°
Seat face outside diameter D:
Inlet valve = 35.5 mm (1.4 in)
Exhaust valve = 30.6 mm (1.2 in)
Valve seat width E:
Inlet valve = 1.75 to 2.25 mm (0.07 to 0.09 in)
Exhaust valve = 2.60 to 2.90 mm (0.10 to 0.11
in)
39. Remove all traces of swarf on completion.
CAUTION: Do not lap replacement valves
to their seats.
Refit
40. Lubricate all components including valve guides
and new valve stem oil seals with engine oil.
41. Insert protective sleeve LRT-12-101 in tappet
bore.
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