MANIFOLD - EXHAUST
DESCRIPTION
The exhaust manifolds are log style with a patented flow enhancing design to maximize performance. The exhaust manifolds are made of high silicon molybdenum cast iron. A multi-layer stainless steel exhaust manifold gasket is used to improve sealing to the cylinder head. The exhaust manifolds are covered by a three layer laminated heat shield for thermal protection and noise reduction. The heat shields are fastened with a torque prevailing nut that is backed off slightly to allow for the thermal expansion of the exhaust manifold, with the exception of the nut, which also secures the oil dipstick tube bracket. That nut should not be backed off.
OPERATION
The exhaust manifolds collect the engine exhaust exiting the combustion chambers, then channels the exhaust gases to the exhaust pipes attached to the manifolds.REMOVAL
EXHAUST MANIFOLD
1. Disconnect negative battery cable.
2. Raise vehicle.
3. Remove exhaust pipe to manifold bolts.
4. Remove engine mount to frame fasteners.
5. Using suitable jack, raise engine enough to remove manifolds.
CAUTION: Do not damage engine harness while raising the engine.
6. Remove the engine mount (Refer to 9 - ENGINE/ENGINE MOUNTING/FRONT MOUNT - REMOVAL) .
7. Remove heat shield.
8. Remove manifold bolts using sequence provided.
9. Remove manifold and gasket.
CLEANING
Clean mating surfaces on cylinder head and manifold. Wash with solvent and blow dry with compressed air.
INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness with a straight edge. Gasket surfaces must be flat within 0.2 mm per 300 mm (0.008 inch per foot).
INSTALLATION
EXHAUST MANIFOLD
1. Install manifold gasket and manifold.
2. Install manifold bolts and tighten to 25 N·m (18 ft. lbs.).
3. Install heat shield and tighten nuts to 8 N·m (70 in. lbs.).
4. Install engine mounts. (Refer to 9 - ENGINE/ENGINE MOUNTING/FRONT MOUNT - INSTALLATION)
5. Lower engine.
CAUTION: Do not damage engine harness while lowering the engine.
6. Install and tighten right and left side engine mount to frame fasteners (Refer to 9 - ENGINE/ENGINE MOUNTING/FRONT MOUNT - INSTALLATION) .
7. Install exhaust flange to pipe bolts.
8. Lower vehicle.
9. Connect negative battery cable.