Volkswagen Workshop Service and Repair Manuals

Repairing valve gear

t

Cylinder heads which have cracks between the valve seats or between a valve seat insert 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 thread are cracked.

t	When new bucket tappets have been installed the engine must not be started for about 30 minutes. (Otherwise valves will contact pistons.) Then turn crankshaft two full revolutions.

1 -

10 Nm

2 -	Inlet camshaft

q	Checking axial clearance → Fig..

q	Removing and installing → Chapter.

q	Check radial clearance with plastigage, wear limit: 0.1 mm.

q	Runout: max. 0.01 mm.

3 -	Drive chain

q	Before removing, mark direction of rotation (installation position) → Chapter.

4 -

10 Nm

5 -

O-ring

q

Renew.

6 -	Inlet camshaft control valve 1 -N205-

q	Only engine codes AGN, AUM, AUQ.

7 -

3 Nm

q	Only engine codes AGN, AUM, AUQ.

8 -	Camshaft adjuster

q	Only engine codes AGN, AUM, AUQ.

q	Engine codes AGU, AQA, ARZ: chain tensioner.

q	Before removing, lock in position with chain tensioner retainer -3366- → Chapter.

9 -

Gasket

q	Rubber/metal gasket.

q

Renew.

10 -	Cylinder head

q	Reworking valve seats → Chapter.

q	Reworking sealing surface → Fig..

q	Sealing transition points → Fig. and → Fig..

11 -

Valves

q	Do not rework, only lapping-in is permitted.

q	Valve dimensions → Fig..

q	Exhaust valves with sodium filling: Observe disposal instructions → Fig..

12 -

Seal

q	Renew → Chapter.

13 -

Screen

q	For Hall sender -G40- / Hall sender 2 -G163-.

q	When installing note fixing arrangement.

14 -

Washer

q

Conical.

15 -

25 Nm

16 -	Hall sender -G40- / Hall sender 2 -G163-

17 -

10 Nm

18 -

65 Nm

q	Use counterhold tool -3036- to loosen and tighten.

19 -	Camshaft pulley

q	Observe installation position: the small web of camshaft pulley faces outwards and the TDC mark for No. 1 cylinder is visible.

20 -

Seal

q	Renew → Chapter.

21 -	Valve guide

q	Checking → Chapter.

22 -	Valve stem seal

q	Renew → Chapter.

23 -	Valve spring

q	Removing and installing: cylinder head removed: use valve spring tool -3362-, installed: → Chapter.

24 -	Valve spring plate

25 -

Cotters

26 -	Bucket tappet

q	Do not interchange.

q	With hydraulic valve clearance compensation.

q	Checking → Chapter.

q	Store with cam contact surface downwards.

q	Before installing check camshaft axial clearance → Fig..

q	Oil contact surface.

27 -	Inlet camshaft bearing cap

q	Installation position and installation sequence → Chapter

28 -	Double bearing cap

q	Must seat on dowel sleeves.

q	Lightly coat contact surfaces with sealant -AMV 174 004 01-, observe installation position and installation sequence → Chapter.

q	Sealing transition points between double bearing cap and cylinder head → Fig..

29 -	Exhaust camshaft bearing cap

q	Installation position and installation sequence → Chapter

30 -	Exhaust camshaft

q	Checking axial clearance → Fig..

q	Removing and installing → Chapter.

q	Check radial clearance with plastigage, wear limit: 0.1 mm.

q	Runout: max. 0.01 mm.

Reworking cylinder head sealing surface The dimension for reworking is measured through the holes for the cylinder head bolts a = minimum 139.2 mm.

Checking camshaft axial clearance Special tools and workshop equipment required t  Universal dial gauge bracket -VW 387- t  Dial gauge Check with bucket tappets and chain removed and No. 2 and 4 bearing caps fitted. Wear limit: max. 0.2 mm.

Valve dimensions   Note Valves must not be reworked. Only lapping-in is permitted.

Dimension		Inlet valve	Exhaust valve
Ø a	mm	26.9	29.9
Ø b	mm	5.963	5.943
c	mm	104.84...105.34	103.64...104.14
α	∠°	45	45

Note Worn sodium filled exhaust valves must not be disposed of without first preparing the valves. They must be cut through in the centre of the stem with a hacksaw. When doing this they must be perfectly dry. The valves prepared in this way can then be thrown into a bucket of water, a maximum of ten at a time. When doing this step back quickly because a sudden chemical reaction causes the sodium filling to burn. After this treatment, the valves can be scrapped as normal scrap.

Sealing transition points between double bearing cap and cylinder head –  Carefully apply a thin coat of sealant -D 454 300 A2- to both edges of sealing surfaces between double bearing cap and cylinder head -arrows- using a small screwdriver.

Sealing transition points chain tensioner/cylinder head or camshaft adjuster/cylinder head –  Carefully apply a thin coat of sealant -D 454 300 A2- to both edges of sealing surfaces between camshaft adjuster and cylinder head -arrows- using a small screwdriver.