Valve command unit - repair — VW

VW
Polo
2003
Engine
4 - Cyl. diesel engine (with unit injectors)
Edition
05.2002
Valve command unit - repair
Note
Engine heads with cracks between valve seats may continue being used , without life cycle reduction, in case the cracks are small, no wider than 0.5 mm.
20 Nm + 90 °
Replace
Follow sequence when tightening and loosing
Chapter
, Valve command shaft - remove and install
Lever shaft
Do not invert
Head screw
Observe sequence when tightening and loosing
Chapter
, remove and install head
Before assembly place washers
Item
on head
Washer
For head screws
Before bearing cap assembly, place washers on head
Hydraulic tap
Do not invert
With hydraulic offsetting of valve course
Place upper side downwards
Before installation, check course axis of valve command shaft
Fig.
Lubrificate friction surfaces
Before removing valve command shaft caps
Keys
Valve spring plate
Valve external spring
Remove and install Head removed: with 2037 installed:
Chapter
, replace valve stem joints
Valve internal spring
Remove and install Head removed: with 2037 installed:
Chapter
, replace valve stem joints
Valve stem oil seal
Replace
Chapter
.
Valve guide
Check
Chapter
.
Unit-pump-injector
Remove and install
Chapter
.
Head
Attention to note
Chapter
.
Sealing ring
Do not lubricate sealing ring
Before installation, remove oil residues from valve command shaft with clean cloth
To install socket on valve command shaft cone use regular adhesive tape
Remove and install
Chapter
.
Valves
Valve measures
Fig.
Caps
Do not invert used caps (identify)
Ensure slots are duly placed on bearing covers and head
Valve command shaft
Check axial play
Fig.
Remove and install
Chapter
.
Measure radial play with
“Plastigage”
: wear limit: 0.11 mm
Oscilation: max. 0.01 mm
Identification, command times
Fig.
Bearing cap
Assembly sequence
Chapter
, Valve command shaft - remove and install
For installation seal bearing 1 and 5 covers separation surfaces with AMV 174 004 01
Fig.
8 Nm + 90 °
Replace
Valve command shaft, check course
Special tools and workshop equipment required
Universal dial gauge bracket
VW 387
Comparer clock
Checking sequence
Perform measuring with tappets removed and first and last bearing cap assembled.
wear limit: max. 0.15 mm
Seal bearings 1 and 5 covers separation surface with AMV 174 004 01
Apply a thin and homogeneous layer of seal AMV 174 004 01 over surfaces
1
.
Note
Ensure no seal enters the grooves
arrows
.
Valve measures
Note
Valves cannot be grinded. Only seating is permitted
Measure
Admission valve
Exhausting valve
∅ a
mm
35.95
31.45
∅ b
mm
6.980
6.956
c
mm
89.95
89.95
α
∠°
45
45
Command shaft identification, command times
Identification:
Cams base circles a = ∅ 52.8 mm.
Identification through numbers and letters stamped on command shaft front face for exhaust valve on cylinder 4.
Cylinder 4
arrow
038 R
or
858 R
Command times in 1 mm stroke of valve
Admission opens after PMS
15.8°
Admission closes after PMI
25,3°
Vent opens before PMI
28.2°
Vent closes before PMS
18.7°