Audi Workshop Service and Repair Manuals

Removing and installing cylinder head Removing l  Engine in vehicle.   Note t  Heat insulation sleeves which are removed must be fitted in the same position when installing. t  All cable ties which are released or cut open when removing must be fitted in the same position when installing. –  Drain off coolant → Chapter. –  Remove intake manifold → Chapter.

–  If fitted, detach air intake hose -1- leading to secondary air pump at air cleaner housing. –  Release hose clip -2- and detach air intake hose from air mass meter -G70-. –  Unplug electrical connector at air mass meter -G70- -item 3-. –  Unscrew bolts -4- and -5- and remove air cleaner housing.

Detach air duct between air cleaner and turbocharger as follows: –  Remove pressure control valve of crankcase breather -1- and mechanical air recirculation valve -2- from air duct. –  Detach hose going to activated charcoal filter at non-return valve -3-. –  Disconnect electrical connector -4- at charge pressure control solenoid valve -N75-. –  Detach hoses -5- and -6- from charge pressure control solenoid valve -N75-. –  Detach air duct -7- from connection on turbocharger and pull out hose -5-, guiding as required.

–  Remove air pipe -arrows-.

–  Unbolt turbocharger from exhaust manifold -arrows-.

Vehicles with variable valve timing: –  Unplug electrical connector -arrow- at inlet camshaft control valve 1 -N205-. All vehicles: –  Unbolt coolant pipe flange from cylinder head (left-side) and move it to one side. –  Remove toothed belt from camshaft sprocket → Chapter. –  Remove cylinder head cover → Chapter.

–  Slacken cylinder head bolts in the sequence: -1 ... 10-. –  Remove cylinder head bolts and detach cylinder head. Installing   Note t  Renew the cylinder head bolts. t  Renew self-locking nuts and bolts when performing assembly work. t  Renew bolts which are tightened to a specified angle as well as oil seals and gaskets. t  Carefully remove any sealant residue from the cylinder head and cylinder block. Ensure that no long scores or scratches are made on the surfaces. t  Carefully remove any remaining emery and abrasive material. t  No oil or coolant must be allowed to remain in the blind holes for the cylinder head bolts in the cylinder block. t  Do not remove new cylinder head gasket from packaging until it is ready to be fitted. t  Handle gasket very carefully. Damage to the silicone coating or the indented area will lead to leaks. t  Cylinder heads which have cracks between the valve seats or between a valve seat insert and the spark plug thread can be re-installed without reducing service life, provided the cracks are only slight and do not exceed a maximum of 0.3 mm in width, and no more than the first 4 turns of the spark plug threads are cracked. t  When installing an exchange cylinder head with fitted camshafts, the contact surfaces between the bucket tappets and cams must be oiled after installing the cylinder head. t  The plastic protectors fitted to protect the open valves must only be removed immediately before fitting the cylinder head. t  Hose connections and hoses for charge air system must be free of oil and grease before assembly. t  Secure all hose connections with the correct type of hose clips (same as original equipment) → Parts catalogue. t  Fit all cable ties in the original positions when installing. t  When fitting a new cylinder head or cylinder head gasket, drain off all the old coolant and refill with new coolant.

–  Set camshaft to “TDC for No. 1 cylinder” before fitting cylinder head -arrows-.

–  Check again that crankshaft is positioned at TDC -arrow-.

–  Fit cylinder head gasket. l  Note position of centering pins -arrows- in cylinder block. l  The Part No. should be legible from inlet side. –  Fit the cylinder head. –  Insert and hand-tighten cylinder head bolts.

–  Tighten cylinder head bolts as follows in the sequence shown: 1.  Tighten with torque wrench to 40 Nm. 2.  Turn 90° (1/4 turn) further using a rigid wrench. 3.  Turn 90° (1/4 turn) further using a rigid wrench.   Note Cylinder head bolts do not have to be torqued down again later after repair work. Remaining installation steps are carried out in reverse sequence; note the following: –  Install cylinder head cover → Chapter. –  Install toothed belt (adjust valve timing) → Anchor. –  Install intake manifold → Chapter. –  Observe notes on procedures required after connecting battery → Rep. Gr.27. –  Check oil level → Chapter.   Note If engine oil is contaminated, perform oil change → Booklet806. –  Fill cooling system with fresh coolant → Anchor. Tightening torques

Component	Nm
Turbocharger to exhaust manifold	30 1)2)
Flange for coolant to cylinder head	10
Hose clips for air hoses	3.5
l  1) Renew bolts. l  2) Coat threads and contact surface of bolt heads with high-temperature paste; for high-temperature paste refer to → Parts catalogue.