Procedures
Valve gear, servicing
Note:
^ Cylinder heads which have cracks between the valve 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 approx. 30 minutes before starting 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
^ For exhaust camshaft
4 - Cylinder head
^ Checking cylinder head for distortion, Go to Fig. 1
^ Reworking cylinder head, Go to Fig. 2
^ Checking valve guides, grinding-in valve seats
^ Sealing connections, Go to Fig. 3 and Fig. 4
5 - Valve guide
6 - Valve stem seal
7 - Valve springs
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.
11 - Intake camshaft
^ Check axial clearance
^ Check radial clearance with Plastigage TM (valve lifters not installed) Wear limit: 0.1 mm; Run-out max: 0.01 mm
12 - Bearing cap/intake camshaft
^ Must be located on dowel sleeves
^ Note installation position
13 - Double bearing cap
^ Must be located on dowel sleeves
^ Seal connections between double bearing cap and cylinder head, Go to Fig. 3
^ Coat sealing surface lightly with D 454 300 02 before installation.
14 - Exhaust camshaft
^ Check axial clearance
^ Check radial clearance with Plastigage TM (valve lifter not installed) Wear limit: 0.1 mm; Run-out max: 0.01 mm
15 - Bearing caphaust camshaft
^ Must be located on dowel sleeves
^ Note installation position
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
^ Seal connections between hydraulic chain tensioner and cylinder head, Go to Fig. 4.
20 - Metal/rubber gasket
21 - Gasket
^ Replace
22 - Exhaust valve
^ With sodium filling
^ Note instructions on scrapping valves with a sodium filling
^ Do not rework; only grinding-in is permitted
^ Valve dimensions Go to Fig. 1
^ Checking valve guides, grinding in valve seats
23 - Intake valve
^ Do not rework; only grinding-in is permitted
^ Valve dimensions Go to Fig. 1
^ Checking valve guides, grinding in valve seats
24 - Oil seal
^ For intake camshaft
25 - Hall sensor rotor
^ Note installation position: locate notch in camshaft
26 - Washer
^ With conical taper
^ Note installation position
27 - 25 Nm
28 - Camshaft Position (CMP) sensor -G40-
29 - 10 Nm
Fig. 1 Valve dimensions
Note:
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.