Cylinder Heads

Cylinder Heads

CAUTION!
Because of the cylinder head threaded connection through the aluminum cylinder block, into the crankshaft bearing bracket (connecting rod). Both cylinder heads must always be removed and installed together. The cylinder block will warp if the bolts are loosened or tightened only on one side.

Special tools, testers and auxiliary items required

• Counter-holder tool (T10172)

• Torque wrench (5 to 50 Nm) (VAG 1331)

• Torque wrench (40 to 200 Nm) (VAG 1332)

• Container for removed components (VAG 1698)

• Engine bung set (VAS 6122)

• Cable tie

Removing

- Remove engine and transmission. Refer to --> [ Engine, Removing ] Engine Removing.

- Remove acoustic covers as well as cylinder head covers from cylinder heads.

- Remove the tandem and fuel pumps from the cylinder heads. Refer to --> [ Tandem and Fuel Pump ] Tandem and Fuel Pump.

- Set crankshaft to Top Dead Center (TDC) cylinder 1. Refer to --> [ Valve Timing Checking ] Testing and Inspection.

- Remove drive gears for camshafts. Refer to --> [ Camshaft Compensation Wheel and Input Gear ] Service and Repair.

- Remove bolts --> [ (Item 8) 20 Nm ] Cylinder Head Assembly Overview between control housing and cylinder head of cylinder bank 1 and 2.

- Loosen and remove cylinder head bolts in the specified sequence (- arrow - points in driving direction).





- Carefully remove the cylinder heads with assistance of a second mechanic.

• The cylinder heads must be carefully guided to prevent damages.

- Place clean clothes into the cylinders so that no dirt or emery cloth particles can get in between cylinder wall and piston.

- Do not allow dirt or abrasive powder to get into coolant either.

- Carefully clean cylinder head and cylinder block sealing surfaces. Avoid introducing scratches or scoring (do not use sandpaper with grit below 100).

Installing

• Always replace cylinder head bolts.

• Only unpack new cylinder head gasket immediately prior to installation.

• Install cylinder head gasket with the same "thickness" index as the one removed.

• Handle gasket carefully. Damages to the silicone layer and in areas of recesses may result in leaks.

- Before installing cylinder heads, position crankshaft to TDC for cylinder 1.

- Turn back crankshaft in opposite direction of engine rotation direction until all pistons stand almost evenly below TDC.

- Set cylinder head gasket in place.

- Position the cylinder head while taking the position of the compensation linkage - arrow - into consideration. Insert the cylinder head bolts with the accompanying washers and tighten by hand.





CAUTION!
All cylinder head bolts, except number - 1 -, - 2 -, - 17 - and - 19 - in tightening sequence must be installed with notched washers.

- Tighten cylinder heads in sequence indicated, in four stages as follows (- arrow - points in driving direction).





1 - Tighten using torque wrench:

First pass = 30 Nm

Second pass = 60 Nm

2 - Tighten further using a ratchet:

Third pass = 1/2 additional turn (180°)

Final pass = 1/2 turn (180°)

- Install drive gears for camshafts. Refer to --> [ Camshaft Compensation Wheel and Input Gear ] Service and Repair.

- Adjust valve timing. Refer to --> [ Valve Timing Adjusting ] Adjustments.