Valve mechanism - repair — VW

VW
Polo
2003
Engine
4 - Cyl. diesel engine (with distributor injection pump)
Edition
05.2002
Valve mechanism - repair
Note
Engine head with cracks between valve seats may continue to be used, without lifecycle reduction, in case the cracks are small – at most 0.5 mm wide.
Bearing caps
Installation position
Fig.
Observe removal and installation sequence
Chapter
, Remove and install crank shaft
Grease support surface of bearing 1 cap with seal AMV 174 004 01
20 Nm
Valve command shaft
Check axial space
Fig.
Remove and install
Chapter
.
Measure radial space with
“Plastigage”
: wear limit: 0.11 mm
Excentricity: maximum 0.05 mm
Determination, command timing
Fig.
Hydraulic tap
Before installation, check axial space of valve command shaft
Fig.
Check
Chapter
.
Do not change
With valve space hydraulic offsetting
Place upper part turned downwards
Lubricate contact surfaces
Keys
Valve spring plate
Valve spring
Remove and install head remove: with fastening lock of valve spring 2037- installed:
Chapter
, replace valve stem seals
Valve stem seal
Replace
Chapter
.
Valve guide
Check
Chapter
.
Seal
To remove and install bearing cap and indented belt
Do not lubricate or grease seal sealing lip
Remove and install indented belt, adjust
Chapter
.
Before installation, remove with clean cloth the oil residues on command shaft neck
To install fitting on command shaft cone use regular adhesive tape (i.e. sellotape)
Engine head
Mind note
Chapter
.
Valves. Grind seats
Chapter
.
Valves
Valve measures
Fig.
Do not grind; only seating is permitted
Check axial space of command shaft
Special tools and workshop equipment required
Universal dial gauge bracket
VW 387
Deflection meter
Measure with removed taps and first and last bearing cap assembled.
Wear limit: max. 0.15 mm
Assembly position of command shaft bearing cap
Observe eccentricity. Before installation of valve command shaft, place bearing caps and check installation position.
Valve measures
Note
Valves cannot be grinded. Only seating is permitted.
Measure
Intake valve
Exhaust system valve
∅ a
mm
35.95
31.45
∅ b
mm
6.963
6.943
C
mm
96.55
96.35
α
∠°
45
45
Identification of command shaft distribution timing
Identification:
Cams base circles a = ∅ 38 mm
Identification through numbers and letters stamped between inlet and outlet cams:
Cylinder 1
arrow A
38E
Cylinder 2
arrow B
External diameter
Distribution timing in valve 1 mm stroke
Intake opens after upper neutral position
11°
Intake closes after lower neutral position
25°
Exhaust system opens berfore lower neutral position
40°
Exhaust system closes before upper neutral position
10°