Valve: Service and Repair

Valve gear, servicing

Notes:
^ Cylinder heads which have cracks between the seats or between valve seat inserts and the spark plug thread can be used further without reducing service life, provided the cracks do not exceed a maximum of 0.3 mm in width, or when no more than the first 4 turns of the spark plug threads are cracked.
^ After installing new lifters wait for approximately 30 minutes before staffing engine. Hydraulic valve compensation elements have to settle (otherwise valves will strike pistons).
^ After working on the valve gear, turn the engine carefully at least 2 rotations to ensure that none of the valves make contact when the starter is operated.





1 - 65 Nm
^ Use counter - hold 3036 to loosen and tighten
2 - Camshaft sprocket
^ For exhaust camshaft
^ Note installation position: camshaft sprocket is installed with smaller side facing out and TDC marking for cylinder 1 visible
3 - Oil seal
4 - Cylinder head
^ Removing, Refer to Cylinder Head, Service and Repair.
^ Checking cylinder head for distortion, Refer to Cylinder Head, Service and Repair, See Fig 1.
^ Reworking cylinder head, Refer to Cylinder Head, Service and Repair, See Fig 2.
^ Checking valve guides, grinding - in valve seats.
^ Installing.
^ Sealing connections, Refer to Cylinder Head, Service and Repair.
5 - Valve guide
^ Checking, Refer to Valve guides, Testing and Inspection.
^ Replacing, Refer to Valve guides, Service and Repair.
6 - Valve stem seal
^ Replacing, Refer to Valve guide seal, Service and Repair.
7 - Valve springs
^ Removing and installing, Refer to Valve guide seal, Service and Repair.
8 - Valve spring plate
9 - Valve keepers
10 - Hydraulic valve lifter
^ Do not interchange
^ Oil contact surface
^ Store with cam contact surface downward
^ Before installing check camshaft axial clearance, Refer to Camshaft, Testing and Inspection.
^ Checking; Hydraulic valve lifters, checking
^ Removing and installing, Refer to Valve guide seals, Service and Repair.
11 - Intake camshaft
^ Valve timing, Refer to specifications.
^ Checking axial clearance, Refer to Camshaft, Testing and Inspection.
^ Removing and installing camshafts, Refer to Camshaft, Service and Repair.
Check radial clearance with plastigage (valve lifters not installed):
^ Wear limit: 0.1 mm
^ Run - out: maximum 0.01 mm
12 - Bearing cap/intake camshaft
^ Must be located on dowel sleeves Note installation position Installation sequence.
13 - Double bearing cap
^ Must be located on dowel sleeves
^ Seal connections between double bearing cap and cylinder head.
^ Coat sealing surface lightly with "D 454 300 02" before installation
14 - Exhaust camshaft
^ Valve timing, Refer to Specifications.
^ Checking axial clearance, Refer to Camshaft, Testing and Inspection.
^ Removing and installing camshafts, Refer to Camshaft, Service and Repair.
Check radial clearance with plastigage (valve lifter not installed):
^ Wear limit: 0.1 mm
^ Run - out: maximum 0.01 mm
15 - Bearing cap/exhaust camshaft
^ Must be located on dowel sleeves
^ Note installation position
^ Installation sequence, Refer to Camshaft, Service and Repair.
16 - 10 Nm
17 - 10 Nm
18 - Drive chain
^ Check for wear
^ Before removing, mark running direction (installation position).
19 - Hydraulic chain tensioner
^ Before removing, lock in position with retainer V.A.G 3366
^ Removing and installing, Refer to Camshaft, Service and Repair.
^ Seal connections between hydraulic chain tensioner and cylinder head.
20 - Metal/rubber gasket
^ Replace, Refer to Camshaft, Service and Repair.
21 - Gasket
^ Replace
22 - Exhaust valve
^ With sodium filling
^ Note instructions on scrapping valves with a sodium filling, Refer to Valve Gear, Servicing.
^ Do not rework; only grinding - in is permitted
^ Valve dimensions, Refer to Fig. 1
23 - Intake valve
^ Do not rework; only grinding - in is permitted
^ Valve dimensions, Refer to Fig. 1
24 - Oil seal
^ For intake camshaft
^ Replacing, Refer to Camshaft Oil Seal, Service and Repair.
25 - Hall sender rotor
^ Note installation position: locate notch in camshaft
26 - Washer
^ With conical taper
^ Note installation position
27 - 25 Nm
28 - Hall sender housing - G40
29 - 10 Nm








Fig. 1 Valve dimensions

Notes: Intake and exhaust valves must not be reworked. Only grinding - in is permitted.

CAUTION:
^ Worn exhaust valves with sodium filling must not be disposed of until they have been treated as follows:
^ The valves must be sawn into two sections with a metal saw at a point between the center of the shaft and the valve head. They must not come into contact with water when this is done.
^ Throw the valves into a bucket of water (not more than ten at time). Then step back because a chemical reaction occurs when the sodium filling burns. After this treatment the valves can be disposed of in the normal way.