Removing and installing cylinder head, ABH, AEC — AUDI

AEC AHK
10 Nm
25 Nm
45 Nm
20 Nm
Tightening torque of intake manifold
1. Stage, 15 Nm
2. Stage, 25 Nm

10 Nm
10 Nm

10 Nm
The longer hexagon of the bolts is inserted in the rear of the cylinder head.

Cylinder head bolts
Replace
Tightening method =>Page
15-54

25 Nm
10 Nm
Combi bolt, 55 Nm
Use holding tool 3036

Cylinder head gasket
Identification: Lettering must face upwards.
Inspect cylinder head for distortion =>Page
15-52
.

Removing

with engine in situ

Notes:

Ask customer for radio anti-theft code.
With the ignition switched off disconnect the battery earth strap. Battery is located on right of luggage compartment beneath trim.
The vibration damper does not have to be unbolted or removed.
Renew all cut and loosened cable ties. Refit cable ties in the same position when installing the engine.
Renew all gaskets and seals.

Removing and installing toothed belt => Page
15-9
.

Notes:

The vibration damper does not have to be unbolted or removed.

Unbolt the exhaust pipe on the left and right.

Disconnect fuel feed and fuel return pipes.
Unbolt the pressure regulator from the fuel rail.

Note:

When installing fuel regulator first of all press fully into the seat of the O-ring seal; do not draw in with the bolts.

Pull breather hose off intake manifold at rear.
Pull off vacuum pipe.
Unscrew upper part of support clamp for engine wiring loom.

Unbolt sheet metal support for ignition cable.

Detach linkage for cruise control system (CCS).
Detach throttle cable by unclipping both retaining clips.

Unbolt heating feeder pipe for coolant at the rear of both cylinder heads.
Detach hose between the supporting clip for the engine wiring harness.

Unbolt both covers for spark plugs.
Unplug spark plug connectors (use detaching device).
Take out ignition cables complete with distributor caps.
Detach connector for knock sensor on left and right.
Pull connector off hot-wire air-mass meter.

Pull connector off throttle valve potentiometer.
Pull connector off thermo switch.
Remove connector at idling speed stabilisation valve.
Remove idling speed stabilisation valve.
Pull off hose to activated charcoal filter (ACF).

Remove air temperature sensor.
Remove the cable bracket behind the rear toothed belt guard on the right, and also on the left as appropriate.

Unbolt bracket for coolant pipe at the rear of the right cylinder head.
Remove heater unit feed pipe from cylinder heads at rear.

Unbolt vacuum unit for cruise control system (CCS) (only when removing the left-hand cylinder head).

Unbolt bracket for CCS vacuum unit (do not forget deflector plate when installing).

Unfasten cylinder head bolts. This is to be done in the reverse order of tightening => Page
15-54
.
Lift off cylinder head.

Checking cylinder head for distortion

Measure at several points with bevelled rule.
Distortion: no more than 0.1 mm

Rework cylinder head

Reworking of cylinder head (face grinding) is only permitted to minimum dimension a = 139.25 mm.

Installing:

Clean sealing surfaces.
Cylinder head gasket: Mark "top" must face cylinder head.
Fit cylinder head, paying attention to centring pins in cylinder block.
Always replace cylinder head bolts.
Insert cylinder head bolts and tighten by hand.

Cylinder head tightening method

Sequence see illustration

Tightening torque (engine cold)
1. Stage · 40 Nm
2. Stage · 60 Nm
3. Stage · 1/2 turn (180o)1)

Continue tightening in one operation using fixed wrench. 2 x 90o further turning is permitted.

Notes:

Cylinder head bolts do not have to be retightened when performing standard service or following repairs.
Before installing intake manifold, first attach front breather hose beneath intake manifold to engine.
Installing cylinder head covers => Page
15-64
.