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Whats the cause of a slightly bent pushrod and a rocker arm to nearly come off?
After replacing my intake gaskets due to vacuum leak and finally getting my engine to start.. a clicking noise appeared and found out my rocker arm nearly fell off the valve spring and a slightly bent pushrod. This happened after installing a taller intake and bigger carb. Also the engine runs a big cam 552.lift Factory rocker arm, factory pushrod and stock gm heads
Re: Whats the cause of a slightly bent pushrod and a...
The high lift cam has no compensation and so the valve retainer bottomed out causing the rocker to slip sideways and bend the push rod
you would have been better fitting a prolonged duration cam rather that a high lift for the following reasons
1 --- you can used standard rocker gear
2 ---there is no valve bounce at high rpm
3 --- smoother air flow in the inlet manifold so there is not such a stop/ start action when rpm is low
4--- less wear on cam followers and cam lobes
cam shafts are all about open duration so longer open with smaller lift is better than the same duration with a fast up and down action
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Before servicing the vehicle, refer to the precautions section.
Drain the cooling system to a level below the coolant pipe on the front of the engine.
Remove or disconnect the following: NOTEKeep the pushrods in order. Intake pushrods are 5 3 / 4 inches long and exhaust pushrods are 6 inches long.
Negative battery cableSpark plug wiresHeater bypass pipePositive Crankcase Ventilation (PCV) valve and hoseRocker arm cover
Rocker arms and pushrods
To install:
Lubricate all the valvetrain components with engine oil.
Install or connect the following:
Pushrods and the rocker arms. Torque the bolts to 24 ft. lbs. (32 Nm).Rocker arm cover using a new gasket. Torque the rocker cover bolts to 89 inch lbs. (10 Nm).PCV valve and hoseHeater bypass pipe. Torque the screw at the water pump to 106 inch lbs. (12 Nm), the bolt at the cylinder head corner to 18 ft. lbs. (25 Nm) and the nut to 18 ft. lbs. (25 Nm).Spark plug wiresNegative battery cable
Refill the cooling system.
Start the vehicle and verify no leaks.
Right Side
Before servicing the vehicle, refer to the precautions section.
Remove or disconnect the following: NOTEKeep the pushrods in order. Intake pushrods are 5 3 / 4 inches long and exhaust pushrods are 6 inches long.
Negative battery cableAlternator bracket on 2005 modelsSpark plug wires from the spark plugs and the upper intake plenum wire retainerPower brake booster vacuum pipe from the intake plenumAccessory drive beltAlternator, if necessaryIgnition coil assembly and Evaporative Emissions (EVAP) canister purge solenoid as an assemblyRocker arm cover
Rocker arms and pushrods
To install:
Lubricate all the valvetrain components with engine oil.
Install or connect the following:
Pushrods and the rocker arms. Torque the bolts to 24 ft. lbs. (32 Nm) plus an additional 30 degree turn.Rocker arm cover using a new gasket. Torque the rocker cover bolts to 89 inch lbs. (10 Nm).Ignition coil and EVAP solenoid assemblyAlternator, if removed. Torque the bolts to 37 ft. lbs. (50 Nm).Accessory drive beltPower brake booster vacuum pipe to the plenumSpark plug wiresNegative battery cable
Rocker arm issues are common in that car. They can happen without any reason. This is not going to be cheap to look at. When the head was repaired it had to be removed. The timing chain might not have been properly tensioned. That would cause the timing chain to slip and then you have pistons slapping valves and spark plugs. This cause rocker arms and pushrods to bend or break and also can damage pistons.
The bolts should have thread lock on them when installing, and the torque is done in 2 steps. 33 ft lbs. and then 90 deg. after that on the second pass.
3.1L Engine CAUTION Observe all applicable safety precautions when working around fuel. Whenever servicing the fuel system, always work in a well ventilated area. Do not allow fuel spray or vapors to come in contact with a spark or open flame. Keep a dry chemical fire extinguisher near the work area. Always keep fuel in a container specifically designed for fuel storage; also, always properly seal fuel containers to avoid the possibility of fire or explosion.
LEFT SIDE (FRONT)
Properly relieve the fuel system pressure.
Disconnect the negative battery cable.
Drain the cooling system into a suitable container.
Disconnect the top half of the air cleaner assembly, then remove the throttle body air inlet duct.
Remove the exhaust crossover pipe heat shield and crossover pipe.
Disconnect the spark plug wires from spark plugs and looms then route the wires out of the way.
Remove the rocker arm (valve) covers.
Remove upper intake plenum and lower intake manifold.
Remove the left side exhaust manifold.
Remove oil level indicator tube.
NOTE: When removing the valve train components they must be kept in order for installation in the same locations they were removed from.
Remove rocker arms nut, rocker arms, balls and pushrods.
Unfasten the cylinder head bolts evenly, then remove the cylinder head from the engine compartment. Remove and discard the gasket.
To install:
Clean all the gasket surfaces completely. Clean the threads on the cylinder head bolts and block threads.
Place the cylinder head gasket in position over the dowel pins on the cylinder block so the words THIS SIDE UP are showing.
Coat the bolt threads lightly with sealer, then install finger-tight.
Tighten the cylinder head bolts in sequence to 33 ft. lbs. (45 Nm). With all the bolts tightened make a second pass tightening all the bolts an additional 90°.
Install the pushrods, rocker arms, balls and rocker arm nuts in their proper locations. Tighten the rocker arm nuts to 18 ft. lbs. (25 Nm).
Install the lower intake manifold and upper intake plenum.
Install the rocker arm (valve) covers.
Install the oil level indicator tube. Insert the dipstick.
Connect the spark plug wires to spark plugs and looms.
Install the left side exhaust manifold.
Install the exhaust crossover pipe and heat shield.
Refill the cooling system.
Install the top half of the air cleaner assembly and the throttle body air inlet duct.
Connect negative battery cable.
Start vehicle and verify that there are no leaks.
Fig. 20: Cylinder head mounting and bolt tightening sequence - 3.1L engine
RIGHT CYLINDER HEAD (REAR) CAUTION Fuel Injection systems remain under pressure, even after the engine has been turned
OFF. The fuel system pressure must be relieved before disconnecting any fuel lines. Failure to do so may result in fire and/or personal injury.
Relieve the fuel system pressure.
Disconnect the negative battery cable.
Drain the cooling system.
Remove the top half of the air cleaner assembly and remove the throttle body air inlet duct.
Remove the exhaust crossover pipe heat shield and crossover pipe.
Raise and safely support the vehicle.
Detach the Oxygen (O2) sensor connector.
Disconnect the exhaust pipe from the exhaust manifold.
Remove the right side exhaust manifold.
Carefully lower the vehicle.
Disconnect the spark plug wires from spark plugs and wire looms and route the wires out of the way.
Remove the rocker arm (valve) covers.
Remove upper intake plenum and lower intake manifold.
NOTE: When removing the valve train components they must be kept in order for installation in the same locations they were removed from.
Remove rocker arms nut, rocker arms, balls and pushrods.
Unfasten the cylinder head bolts evenly, then remove the cylinder head from the engine compartment. Remove and discard the gasket.
To Install:
Clean all the gasket surfaces completely. Clean the threads on the cylinder head bolts and block threads.
Place the cylinder head gasket in position over the dowel pins on the cylinder block so the words THIS SIDE UP showing.
Coat the bolt threads lightly with sealer, then install finger-tight.
Tighten the cylinder head bolts in sequence to 33 ft. lbs. (45 Nm). With all the bolts tightened make a second pass tightening all the bolts an additional 90°.
Install the pushrods loosely retained with the rocker arm assemblies. Make sure all pushrods are in the correct locations. Coat the ends of the pushrods with prelube. The intake rods are marked yellow and are 5 3?4 inch long. The exhaust pushrods are marked green and 6 inches long. balls and rocker arm nuts. Tighten the rocker arm nuts to 18 ft. lbs. (25 Nm).
Install the lower intake manifold and upper intake plenum.
Install the rocker arm (valve) covers.
Connect the spark plug wires to spark plugs and wire looms.
Raise and safely support the vehicle.
Install the exhaust manifold.
Connect the exhaust pipe to the exhaust manifold.
Carefully lower the vehicle.
Connect the Oxygen (O2) sensor wiring.
Install the exhaust crossover pipe and heat shield.
Refill the cooling system.
Install the top half of the air cleaner assembly and the throttle body air inlet duct.
Exactly what is the wrong? Need the part? Need to know torque adjust or porcedure to take off? For 1994 Pontiac Grand Am 3.1L SFI OHV 6cyl check this procedure for Intake Manifold... (see Figure 14) The 3.1L engine is equipped with upper and lower intake manifolds.
The upper intake manifold is also known as the intake manifold plenum.
CAUTION
The fuel system is under pressure and must be properly relieved
before disconnecting the fuel lines. Failure to properly relieve the
fuel system pressure can lead to personal injury and component damage.
Relieve the fuel system pressure.
Disconnect the negative battery cable.
Remove top half of the air cleaner assembly and throttle body duct.
Drain and recycle the engine coolant.
Disconnect the EGR pipe from exhaust manifold.
Remove the serpentine belt.
Remove the brake vacuum pipe at the intake plenum.
Disconnect the control cables from the throttle body and intake plenum mounting bracket.
Remove the power steering lines at the alternator bracket.
Remove the alternator.
Label and disconnect the ignition wires from the spark plugs and wire retainers on the intake plenum.
Remove the ignition assembly and the EVAP canister purge solenoid together.
Fig. 14: View of the intake manifold and related components
Disconnect the upper engine wiring harness connectors at the following components:
Throttle Position Sensor (TPS)
Idle Air Control (IAC)
Fuel Injectors
Coolant temperature sensor
Manifold Absolute Pressure (MAP) sensor
Camshaft Position (CMP) sensor
Tag and disconnect the vacuum lines from the following components:
Vacuum modulator
Fuel pressure regulator
PCV valve
Disconnect the MAP sensor from upper intake manifold.
Remove the upper intake plenum mounting bolts and lift off the plenum.
Disconnect the fuel lines from the fuel rail and bracket.
Install engine support fixture special tool J 28467-A or an equivalent.
Remove the right side engine mount.
Remove the power steering mounting bolts and support the pump out of the way without disconnecting the power steering lines.
Disconnect the coolant inlet pipe from the outlet housing.
Remove the coolant bypass hose from the water pump and the cylinder head.
Disconnect the upper radiator hose at thermostat housing.
Remove the thermostat housing.
Remove both rocker arm covers.
Remove the lower intake manifold bolts. Make sure the washers on
the four center bolts are installed in their original locations.
When removing the valve train components they should be kept in order for installation the original locations.
Remove the rocker arm retaining nuts or bolts and extract the rocker arms and pushrods.
Remove the intake manifold from the engine. Remove and discard the gasket.
Using a suitable scraper, clean gasket material from all mating
surfaces. Remove all excess RTV sealant from front and rear ridges of
cylinder block
To install:
Place a 0.12 inch (3mm) bead of RTV, on each ridge, where the front and rear of the intake manifold contact the block.
Using a new gasket, place the intake manifold on the engine.
Install the pushrods in their original locations. Coat the pushrods with prelube.
The intake pushrods are marked yellow (5
3
/4 inch long) and the exhaust are green (6 inches long).
Make sure the pushrods are properly seated in the valve lifters and
rocker arms.
Position the rocker arms in there original locations and tighten
to specifications. Refer to the procedure earlier in this section.
Install lower the intake manifold attaching bolts. Apply sealant
12345739 (or equivalent thread locking compound) to the threads of
bolts. Tighten the vertical bolts first then the diagonal bolts to 115
inch lbs. (13 Nm).
Install the front rocker arm cover.
Install the thermostat housing.
Connect the upper radiator hose to the thermostat housing.
Fasten the coolant inlet pipe to thermostat housing.
Connect coolant bypass pipe at the water pump and cylinder head.
Install the power steering pump in the mounting bracket.
Loosely install the serpentine belt.
Connect the right side engine mount.
Remove the special engine support tool.
Fasten the fuel lines to fuel rail and bracket.
Install the upper intake manifold and tighten the mounting bolts to 18 ft. lbs. (25 Nm).
Install the MAP sensor.
Connect the upper engine wiring harness connectors to the related components removed earlier.
Connect the vacuum lines to the PCV, vacuum modulator and fuel pressure regulator.
Install the EVAP canister purge solenoid and ignition assembly.
Install the alternator assembly.
Connect the power steering line to the alternator bracket.
Install the serpentine belt.
Connect the spark plug wires to the spark plugs and intake plenum wire retainer.
Install the EGR pipe to the exhaust manifold.
Attach the control cables to the throttle body lever and upper intake plenum mounting bracket.
Install air intake assembly and top half of the air cleaner assembly.
Install the brake vacuum pipe.
Fill the cooling system.
Connect the negative battery cable, then start the vehicle and verify that there are no leaks.
If the engine oil was full of antifreeze when the intake gasket went bad, then there is a good chance that there may be some cam and/or lifter damage. A more likely cause of your problem would be that the push rods got mixed up when you put it back together. The intake and exhaust rods are different lengths. If this is the case, and you have turned the engine over, there is a good chance that you now also have a bent pushrod and intake valve. The exhaust pushrod is the longer one and if you mix them up, the piston will contact the intake valve because it will not be able to close due to the longer pushrod. This will bend or break the pushrod and bend the valve stem.
2.2L Engine & 2.4L Engines These engines are not equipped
with rocker arms. The camshafts directly actuate the valves.
3.1L Engine & 3.4L Engines When install or connect the check the following: - Pushrods and the rocker arms. Torque the bolts to 24 ft. lbs. (32
Nm).
- Rocker arm cover using a new gasket. Torque the rocker cover bolts
to 89 inch lbs. (10 Nm). - Heater bypass pipe. Torque the screw at the water pump to 106 inch
lbs. (12 Nm), the bolt at the cylinder head corner to 18 ft. lbs. (25
Nm) and the nut to 18 ft. lbs. (25 Nm).
About the INTAKE MANIFOLD... - Intake manifold nuts and bolts and tighten to 89 inch lbs. (10 Nm) - Pushrods and rocker arms. Torque the bolts to 89 inch lbs. (10 Nm)
plus an additional 30 degree turn.
- Lower intake manifold. Apply sealant to the threads of the bolts
and torque the bolts to 115 inch lbs. (13 Nm).
Exploded view of the upper and lower intake-3.1L & 3.4L
engines
it sounds like you installed the wrong gaskets. this allows air to leak past the gasket causing a massive vacuume leak. It could also be the gasket is too small chocking off the air and causing the car to run rich.
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