SEAT Workshop Service and Repair Manuals

Servicing valve gear

t

Cylinder heads which have cracks between the valve seats or between the 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 thread of spark plug hole is cracked.

t	When installing new bucket tappets, the engine must not be started for 30 minutes (otherwise valves may strike piston crown). Then turn crankshaft two full rotations further.

1 -

Bolt

q	20 Nm + 1/4 turn (90°) further

q

Renew

2 -	Camshaft sprocket

q	Observe position when fitting toothed belt → Chapter

3 -

Seal

q	Lightly oil sealing lip of seal

q	Renewing → Chapter

q	Renew only when camshaft is installed

4 -

Bolt

q	6 Nm + 1/4 turn (90°) further

5 -	Bearing cap 0…4

q	Installation position and installation sequence → Chapter, Removing and installing camshaft

q	Lightly coat contact surfaces on bearing cap 0 with sealant -AMV 174 004 01-

6 -	Bearing cap 10

q	For ignition distributor securing device

q	Lightly coat contact surfaces with sealant -AMV 174 004 01-

7 -

Camshaft

q	Checking axial clearance → Fig.

q	Removing and installing → Chapter

q	Check radial clearance with Plastigage Wear limit: 0.1 mm

q	Run-out: max. 0.01 mm

q	Identification marks and valve timing → Fig.

q	Oil before installing

q	Renewing oil seal → Chapter

8 -	Bearing cap 5…9

q	Installation position and installation sequence → Chapter, Removing and installing camshaft

q	Lightly coat contact surfaces on bearing cap 5 with sealant -AMV 174 004 01-

9 -	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

10 -	Valve cotters

11 -	Valve spring plate

12 -	Valve spring

q	Removing and installing: Cylinder head removed: with -T20034/1- installed: → Chapter Renewing valve stem seals

13 -	Valve stem seal

q	Renewing → Chapter

14 -	Valve guide

q	Checking → Chapter

q	Renewing → Chapter

15 -	Repair valve guide

q	With shoulder

16 -	Cylinder head

q	Reworking valve seat → Chapter

q	Reworking sealing surface → Fig.

17 -

Valve

q	Do not rework, only lapping-in is permitted

q	Valve dimensions → Fig.

18 -

Bolt

q

20 Nm

19 -

Bracket

20 -	Non-return valve

q

6 Nm

q	Insert with D6

q	Do not over tighten, otherwise valve may stick.

21 -	Sealing plug

q	Insert with D6

q

40 Nm

Reworking cylinder head sealing surfaces Reworking dimensions for cylinder head: a = at least 128,1 mm   Note! When the sealing surfaces have been reworked the valves must be set deeper by the same amount (rework valve seat inserts), otherwise the valves will strike the piston crown. When doing this ensure that the permissible minimum dimension is maintained → Chapter.

Checking camshaft axial clearance Special tools and workshop equipment required t  Universal dial gauge holder -T20020- t  Dial gauge Measure with bucket tappets removed and bearing caps 2 or 7 fitted. Wear limit: max. 0.15 mm

Camshaft identification, valve timing Identification

	Marks between cam lob pair for cylinders No. 3 and 4
Inlet shaft -E-	“EIN” and “036BH”
Exhaust shaft -A-	“AUS” and “036R”

Valve timing at 1 mm valve lift The cam lobs of the individual cam pairings are offset to one another. Therefore differing timing is achieved for cam lobs “a” and “b”.

	Cam lob “a”	Cam lob “b”
Inlet opens ATDC	12 °	10 °
Inlet closes ABDC	32 °	30 °
Exhaust opens BBDC	28 °	30 °
Exhaust closes BTDC	8 °	10 °

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

Dimension		Inlet valve	Exhaust valve
Ø a	mm	29,5	26,0
Ø b	mm	5,973	5,953
c	mm	97,8	97,2
α	∠°	45	45