How to Replace a Head Gasket in a 5.7 Chevroletby Jennifer Reed
The 5.7-liter 350 Chevrolet engine has been installed in GM trucks, passenger cars and sport cars since 1967. If the head gasket on this engine fails, it will need to be replaced. Coolant leaking from the head gasket or water mixed in the oil are the usual symptoms of a blown head gasket. Parts for the Chevrolet 5.7-liter engine are plentiful; you will be relieved to find that most auto part stores have the required parts to replace a head gasket on the 350.
Disconnect the battery terminals and remove the air cleaner. Disconnect the fuel lines and any connectors from the intake and distributor. Using the tape, tag and number each ignition wire. Disconnect the ignition wires from the spark plugs. Mark the distributor housing to the intake with a paint pen. Remove the distributor cap. Mark the distributor rotor to the cap. Loosen the retainer bolt for the distributor. Lift the distributor up and out of the engine.
Unbolt the valve covers and lift them off the cylinder heads. Remove the bolts from the intake (it might be necessary to pry around the edges of the intake with the screwdriver). Work the intake side-to-side, until it separates from the engine block. Remove the rocker arm nuts and lift the rocker arms off the studs. Slide the push rods out of the guides.
Unbolt the exhaust manifolds from the sides of the cylinder heads. Remove the bolts that are located on the outer perimeter of the cylinder heads. Remove the remaining bolts from the inner surface of the heads. Lift the heads away from the dowel pins. If they do not break free, pry around the heads with the screwdriver. Remove the old head gaskets. Spray the solvent liberally onto the exposed engine block surface. Scrub the mating surface of the engine block with the wire brush. Repeat the cleaning procedure until the old gasket remnants are completely removed.
Align the new head gaskets to the dowel pins and press the gasket down. Place the heads onto the engine block. Prevent the head from falling by loosely installing the head bolts (the head bolts have to be tightened in a specific pattern with the torque wrench--starting from the center working out, tighten the head bolts to manufacturer specifications). Slide the push rods into the guides. Install the rocker arms and nuts. Set the valve lash. Place the new intake gaskets onto the engine block. Apply RTV sealant to the front and back of the block, where the intake will seat. Place the intake manifold onto the block. Install the intake bolts and torque to manufacturer specifications.
Line up the distributor and push it into place. Tighten the distributor retaining bolt. Reinstall the distributor cap and connect the ignition wires onto the spark plugs. Reinstall the exhaust manifolds, with new gaskets, and tighten the bolts. Place the valve cover gaskets on the valve covers. Reinstall the valve covers onto the heads. Install the valve cover bolts and tighten to manufacturer specifications. Reconnect all fuel lines and connectors. Tighten the battery terminals.
- Clean the engine bay prior to repair. Brake Clean is an effective solvent to use on the engine. Wipe down any surface that a gasket or RTV is to be applied to. Wiping the surface with Brake Clean will ensure that no oil film interrupts the sealing process. Listen for the snap of the ignition wires engaging the crown of the spark plug.
- Do not use too much RTV sealant on any surface. It is very important to set the valve lash properly--severe cylinder head or push rod damage could occur otherwise.
Items you will need
- Complete socket set
- Torque wrench
- Head gasket kit
- Wire brush
- Shop rags
- Fine-point paint pen
- Paper tape
- Flat-head screwdriver
- RTV sealant
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