Cylinder head repair (VW Touareg 1)

Checking the piston position at top dead center

It is impossible to measure the piston protrusion in the service station conditions. The cylinder head is connected to the aluminum cylinder block using the anchor principle with anchor bolts. This achieves such compression of the cylinder block that it is impossible to achieve with the cylinder head removed. For this reason, when replacing the cylinder head gasket, it is necessary to install a new cylinder head gasket with identical index marking.

Piston and cylinder dimensions

NOTE: Repair sizes are not provided.

Grinding size	Piston	Cylinder
Nominal size, mm	80,97	81,01

Checking the thermal clearance of piston rings

Drive the piston ring from above, at a right angle to the cylinder wall, to the bottom hole of the cylinder, at a distance of about 15 mm from its edge (fig. 2.209).

Piston ring	Thermal gap
	new	wear limit
1. Compression ring, mm	0,20-0,40	1,0
2. Compression ring, mm	0,30-0,50	1,0
Oil scraper ring, mm	0,25-0,50	1,0

Checking the piston ring clearance by height

Clean the ring groove before checking (fig. 2.210).

Piston ring	Height clearance
	new	wear limit
1. Compression ring, mm	0,04-0,09	0,15
2. Compression ring, mm	0,03-0,06	0,15
Oil scraper ring, mm	0,02-0,06	0,15

Checking the cylinder diameter

Measure the transverse distance A and the longitudinal distance B in three places in a cross shape (fig. 2.211).



Maximum permissible deviation from the nominal size: 0.05 mm.

Piston: mounting position and piston/cylinder assignment-

The following markings are applied to the bottom of the piston:

• pistons 1-5 for cylinder bank 1;
• pistons 6-10 for cylinder bank 2.

Position: The arrow on the bottom of the piston points to the suction side.

Checking the axial displacement of the camshaft

Checking with the plate tappets removed and the bearing caps installed (fig. 2.212).



First row of cylinders:

• bearing caps 2, 4 and 6 are installed

Second row of cylinders:

• bearing caps 9, 11, and 13 are installed

Wear limit: max. 0.15 mm/

Apply sealant to the seating surfaces of the outer bearing caps.

Work execution procedure

Apply sealant AMV 176 501 to the surfaces in a thin, even layer 1 (fig. 2.213).



First row of cylinders:

• Apply sealant - AMV 176 501 to the seating surfaces of bearing caps 1 and 7

Second row of cylinders:

• Apply sealant AMV 176 501 to the seating surfaces of bearing caps 8 and 14

Valve sizes

NOTE: Valves must not be machined. Only lapping is permitted.

Size	Short intake valve	Long intake valve
a, mm	35,950	31,450
b, mm	6,980	6,956
s, mm	89,950	89,950
a, hail	45	45

Camshaft marking (valve timing)

Main circumference of the valve cam: a = 52.8 mm. Marking is applied in the form of stamped numbers and letters on the end surface of the camshaft drive side (fig. 2.215).



Drive side

• First row of cylinders: 07Z G.
• Second row of cylinders: 07Z H.

Valve timing with a valve stroke of 1 mm

The intake opens after TDC	12,0°
The intake closes after BDC	21,5°
The issue opens before NMT	30,0°
The release closes before TDC	20,5°