1990 Jaguar Sovereign cylinderhead

CYLINDER HEAD R & I
Removal
Relieve fuel pressure. See FUEL PRESSURE RELEASE under REMOVAL & INSTALLATION. Disconnect negative battery cable. Remove intake manifold. See INTAKE MANIFOLD under REMOVAL & INSTALLATION. Remove thermostat housing. Remove distributor cap and spark plug wires.
Rotate crankshaft until No. 1 piston is at TDC. Note rotor and distributor location for installation reference. Remove distributor. Raise and support vehicle. Remove exhaust bracket from transmission. Disconnect exhaust downpipes from manifolds. Lower vehicle. Remove cam cover.
Rotate crankshaft until timing notches in camshaft flanges are pointing down. Remove 2 accessible camshaft sprocket mounting bolts (per camshaft) and lock tabs. Rotate crankshaft until Timing Gauge (18G 1433) can be inserted into slot of camshaft front flange.
CAUTION:DO NOT rotate crankshaft while camshaft sprocket is disconnected from camshaft. Serious damage to valve train components may occur.

Remove remaining camshaft sprocket mounting bolts and lock tabs from camshafts. Remove tensioner valve clamp bolt, and swing clamp away from center of chain tensioner. See Fig. 1. Remove valve from center of tensioner. Insert 3-mm Allen wrench into center of tensioner.
Turn Allen wrench clockwise until tensioner is in the fully relieved position. Remove remaining chain tensioner bolt. Remove chain tensioner, "O" ring and gasket. Remove camshaft sprockets from camshafts. Remove cylinder head-to-engine block front nuts/bolts.
Remove upper chain guide. Remove remaining cylinder head bolts. Check for wires, hoses or any other components that are still attached. Remove cylinder head and gasket.
Inspection
Ensure all mating surfaces are clean. Measure cylinder head for warpage. If warpage exists, disassemble and resurface cylinder head. Maximum resurface limit is.010" (.25 mm).
CAUTION:Always use NEW cylinder head bolts

Installation
Install NEW head gasket. Using Timing Gauge (18G 1433), ensure camshafts are still at TDC. Ensure No. 1 piston is still at TDC. Install cylinder head. Tighten NEW cylinder head bolts in sequence to 45 ft. Lbs. (61 N.M), then turn bolt an additional 90 degrees. See Fig. 2.
Position wiring harness clip and hose bracket, and install front cylinder head bolts. Fit camshaft sprockets onto camshafts. Move all slack in timing chain to tensioner side. Install Upper Chain Tensioner Tool (18G 1436) See Fig. 3. Tighten center bolt on tensioner tool to tension the upper chain.
Remove inner sprocket retaining clip. See Fig. 4. Remove inner sprocket, and align sprocket holes with holes in camshaft. Reinstall inner sprocket. Install lock tabs and retaining bolts. Install inner sprocket retaining clip.
Remove tensioner tool. Clean tensioner gasket mating surfaces. Install NEW tensioner gasket. Lubricate and install NEW "O" ring on tensioner. Install tensioner assembly into cylinder head. Tighten lower tensioner retaining bolt. DO NOT tighten valve clamp bolt at this time.
Clean tensioner valve assembly, and install NEW "O" rings. Insert 3-mm Allen wrench into center of tensioner. Turn Allen wrench counterclockwise to release tensioner. Lubricate and install tensioner valve.
Position tensioner clamp over tensioner valve. Tighten tensioner clamp bolt. Using NEW gasket and cam cover seals, install cam cover. Install distributor and cam cover breather. To complete installation, reverse removal procedure.