Cylinder Head Assembly: Service and Repair
REMOVAL1. Place protective covers on fenders and disconnect ground cable from battery.
2. Remove air cleaner assembly complete with air mass sensor. Remove engine covers.
3. Undo distributor cap, pull off plug connectors, unclip cover for fuel rail and put aside along with ignition leads.
4. Pull off connector for oil temperature sender and camshaft adjuster. Unscrew fuel return and feed lines from fuel pipe, making sure a second wrench is used to lock. Undo fuel rail at intake distributor and take out along with injector valves. Put fuel rail complete with wiring harness to the rear. Do not kink fuel lines.
5. Remove engine undertray. Undo exhaust system at exhaust manifold I exhaust pipe flange.
6. Pull off coolant hose between reservoir and thermostat housing and catch coolant in a suitable container.
7. Remove ATF reservoir from body. Remove coolant pipe with heater valve. Bend heat shroud slightly forwards.
8. Pull connector off idle speed positioner and throttle valve switch. Unhook throttle valve operating gear and remove bracket complete with idler. Pull vacuum hose off intake rail and throttle body. Remove coolant hose from reservoir at throttle body.
9. Remove oil dipstick. Pull vacuum non-return valve from brake booster. Remove coolant hose between radiator and cylinder head from breather flange. Undo intake rail at lefthand engine mount.
10. Remove bracket for oxygen sensor connector from intake rail. Loosen breather hose at oil separator and coolant hoses at connecting flange and pull off. Remove wiring harness bracket from connector flange.
11. Detach and remove intake rail from cylinder head. Remove rocker cover, toothed belt cover and camshaft sprocket console.
12. Rotate engine in direction of rotation and set engine to firing TDC of cylinder No. 1. Slacken camshaft toothed belt and pull belt oft camshaft sprocket, Timing Belt.
13. Take out distributor rotor. Tighten camshaft sprocket with three M 5 x 20 mm auxiliary screws to keep the basic camshaft setting from shifting when the central camshaft bolt is removed.
14. Undo central bolt, making sure a second wrench is used to lock. Remove camshaft sprocket and rear console. Disconnect connector for Hall sender unit.
15. Remove "VarioCam" camshaft adjuster from cylinder head. Remove bearing cap from cylinders No. 1 and 3. Retain both camshafts in bearings using Special Tool 9226. Undo and lift off front twin bearing saddle and remaining bearing caps. For installation of camshafts, Camshaft
16. The rear twin bearing saddle may remain attached to the cylinder head. Loosen Special Tool 9226 in a uniform manner and remove both camshafts complete with camshaft adjuster and put them aside.
17. Undo cylinder head. Undoing sequence: From outside to inside. Lift off cylinder head. (If tolerances are too narrow, the right- hand engine bracket must be separated from the hydraulic mount)
NOTE: If traces of oil ingress in the water are found, the cylinder head must be examined closely by visual inspection for hairline cracks. For this purpose, check the cooling system for tightness. Run tightness check with tester VW 1274 across the reservoir (max. pressure 1 bar (14.5 psi). The camshaft cap must be removed for visual checking.
INSTALLATION
NOTE: The cylinder head may be fitted with the engine remaining in the car.
1. Place cylinder head gasket into correct position.
2. Fit cylinder head.
Tightening sequence:
Cylinder head tightening specifications
1st stage 20 Nm (15 ft lb)
2nd stage 60 ° turning angle
3rd stage 90 ° turning angle
NOTE: Do not use any lubricant when fitting the cylinder head nuts and washers. Only the threads of the studs should receive a thin coat of engine oil.
3. Replace gaskets, seals and 0-rings before fitting the cylinder head. Tighten nuts and bolts to the specified torque.
4. Top up coolant and bleed cooling system. Warm up engine to operating temperature, check coolant level again and top up if required.