Cylinder Head, Intake Manifold, Exhaust Manifold: Removal
WARNING: This page is about a different car, the 2002 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
Refer to these figures throughout procedure. See Figure-Figure .
- Release fuel pressure. See FUEL PRESSURE RELEASE . Disconnect negative battery cable. Drain cooling system. Remove engine "V" bank and side covers. Remove air cleaner assembly and intake air duct. Disconnect EVAP hose from charcoal canister. Remove radiator assembly. Remove 4 "V" bank cover mounting brackets.
- Remove throttle body. Disconnect all necessary fuel lines, vacuum hoses and electrical connectors from intake manifold and cylinder heads. Remove bolts and disconnect wiring harness retaining clamps from upper intake manifold, and left hand camshaft bearing cap. Remove 2 bolts and disconnect wiring harness retainer from right hand cylinder head, and rear water bypass manifold.
- Disconnect 8 injector connectors. Remove 6 bolts and 4 nuts, and remove intake manifold assembly. Disconnect timing belt from camshaft sprockets. See TIMING BELT REPLACEMENT - 4.3L article. Remove camshaft sprockets. Remove camshaft position sensor. Remove rear timing belt plates from both cylinder heads.
- Remove power steering pump from engine and suspend aside. Raise and support vehicle. Disconnect front exhaust pipe from three-way catalytic converters (TWC) on exhaust manifolds. Remove TWCs from exhaust manifolds. Lower vehicle. Remove water bypass pipe. Disconnect water temperature sender. Remove 4 bolts and remove water bypass manifold.
- Remove ignition coils. Remove Variable Valve Timing (VVT) sensors. Remove engine hangers. Remove engine and transmission oil dipsticks and guide tubes. Remove valve covers. Remove camshaft timing oil control valve from both front camshaft bearing caps.
- To avoid valve/piston interference, ensure timing mark on crankshaft pulley is aligned with center of crankshaft pulley bolt and center of No. 2 timing belt idler pulley bolt. See Fig 1. Remove camshafts. See CAMSHAFT .
- Disconnect oxygen sensor harness connectors. Disconnect body ground leads from rear of each cylinder head. Remove oxygen sensor wiring harness bracket from left hand cylinder head. Remove wiring harness bracket from right hand cylinder head.
- Loosen cylinder head bolts evenly in several steps, in sequence. See Fig 2. Remove cylinder head bolts, washers, cylinder head and cylinder head gasket.CAUTION: To prevent cylinder head warpage or cracking, loosen cylinder head bolts evenly, in proper sequence. See Fig 2. DO NOT allow cylinder head bolt washers to drop into engine through either end of cylinder head.NOTE: If cylinder head removal is difficult, carefully pry between cylinder head and projected area near front of cylinder block. DO NOT damage sealing surfaces on cylinder block and cylinder head.
- Remove heat insulators. Remove exhaust manifolds and gaskets from cylinder head. Using a valve spring compressor, remove keepers, spring retainers, springs and valves. Using needle nose pliers, remove valve stem oil seals.