Repair 7

The 1964 Ford Thunderbird was fitted only with the 390 cubic-inch engine. The 390 was a big-block engine and featured exhaust manifolds that tilted downward at a sharp angle, making removal difficult. To make matters worse, the Thunderbirds engine compartment was relatively small. Whereas the exhaust manifolds on most cars of the time could be removed from the top of the engine compartment, the Thunderbirds limited access requires that some bolts be removed from above the car and the others from underneath it.

Instructions

1

Raise the hood and remove the bolt at the center of the manifold, the three bolts at the front of the manifold and the bolt at the top of the back end of the manifold with a wrench.

2

Raise the front of the car with a jack to increase the work space underneath the car, then lower the Thunderbird onto safety stands.

3

Remove the two bolts that secure the exhaust pipe to the back of the manifold with a wrench, then pull the pipe away from the manifold.

4

Remove the two remaining exhaust manifold bolts from underneath the car with a wrench.

5

Pull the manifold off of the cylinder head from above the engine compartment.

6

Guide the manifold out of the engine compartment from underneath the vehicle.

The fourth generation of the 1500 series pickup truck appeared in 1988 and was manufactured until 2000 by Chevrolet. There were a total of eight different versions and cab variations of the 1500. They were powered by reliable V8 engines that required periodic service if parts like the intake manifold gasket would fail.

Instructions

Removal Procedure

1

Mark the relationship of the distributor housing and rotor for proper reassembly. Remove the distributor. Unplug the upper radiator hose at the thermostat housing. Remove the heater hose at the lower intake manifold. Remove the EGR valve and the coolant bypass hose.

2

Pull out the fuel supply and return lines from the rear part of the intake manifold. Unplug the wiring harness and brackets. Remove the throttle cable and bracket. Remove the cruise control cable.

3

Take out the transmission oil level indicator tube. Remove the EGR inlet tube, clamp and bolt. Remove the PCV valve and vacuum hoses. Unscrew the air conditioning compressor. Loosen the A/C compressor mounting bracket and slide forward, but do not remove it. Lay the A/C compressor out of the way. Do not kink the air conditioning lines.

4

Remove the power brake vacuum tube and the rocker arm cover. Remove the generator rear bracket bolt. Take out the intake manifold. Remove the old pieces of gasket from the gasket surfaces. Clean the excessive carbon buildup from inside the exhaust passages and the scale and deposits from the coolant passages. Inspect the manifold for cracks, broken flanges and gasket surface damage.

Installation Procedure

5

Position the new gaskets to the cylinder head with the port blocking plates facing the rear of the engine and "This Side Up" facing up. Install the lower intake manifold on the engine. Apply sealer to the lower intake manifold bolts. Put in the lower intake manifold bolts back in place. Tighten the bolts in three steps. In the first step apply 27 inch pounds of torque. In the second apply 106 inch pound of torque and in the last step tighten the bolts applying 11 foot pounds of torque.

6

Plug in the wiring harness connectors and brackets. Connect the upper radiator hose at the thermostat housing. Install the heater hose at the lower intake manifold. Connect the coolant bypass hose.

7

Install the EGR valve and the valve rocker arm cover. Connect the fuel supply and return lines at the rear of the intake manifold. Plug in the wiring harness and brackets. Install the cruise control cable (if equipped).

8

Install the throttle cable and bracket. Put back the transmission oil level indicator tube. Install the EGR inlet tube, clamp, and bolt. Connect the PCV valve and vacuum hoses. Install the power brake vacuum tube. Install the generator and the bracket bolt (if needed). Install the air conditioning compressor and bracket. Refer to Heating and Air Conditioning. Connect the distributor. Note the relationship of the distributor housing and rotor made at disassembly.

Car engines rely on proper mixtures of air and fuel to perform at peak levels. One component of the engine, the intake manifold, helps with this mixing process, but can have problems with leakage from the intake manifold gasket.

Function

An intake manifold gasket seals the two pieces of the intake manifold assembly together to keep the air and fuel mixture from leaking out. The intake manifold itself distributes this mixture to the engines cylinders for combustion.

Considerations

Intake manifold gasket problems arise as the engine ages. Current day stock gaskets are made from nylon-filled plastic carriers, which can warp from the constant change of air pressure and heat within the intake manifolds body over the course of a vehicles lifespan. If a gasket is failing, there may be visible leakage and an obvious decrease in engine performance.

Prevention and Solution

Many aftermarket intake manifold gaskets are manufactured with aluminized steel carrier bodies to shore up the integrity of the gasket. Keep in mind that the torquing of the manifold assembly around the gasket should be monitored to make sure that the gasket is tightened securely, but is not pinched.

Exhaust manifolds work in very punishing conditions. They conduct exhaust gasses with core temperatures that top 1,000 degrees F from the engine to the exhaust pipes. Many stock and aftermarket manifolds enhance engine performance by improving scavenging and flow dynamics of the exhaust gasses as they exit the engine head. Most manifolds are made of cast iron and cannot be welded. Any repairs involving additional metal must be done by brazing with an oxy-acetylene torch and iron brazing rods.

Instructions

Repairing the Manifold

1

Clean the manifold and the broken off flange well. Be certain the parts are free of rust and carbon. Nest the flange back into position to make sure it will mate properly and be in the original plane. Clamp the broken flange with Vise-Grips at the edge furthest from the joint.

2

Heat the joint with a torch while holding the flange in place. Apply heat until the native metal begins to melt and puddle. Begin feeding the iron brazing rod into the puddle as the puddle begins to form. Move the torch focal point and the rod along the joint with a steady and slow motion, constantly melting the native metal and replacing it with the rod material. Braze as much as possible before stopping to flip the manifold to can gain access to the other side. Continue this process until the entire joint has been brazed.

3

Cool the repaired area slowly. Hold the torch back a little from the actual brazing distance and wash the flame over the repair and the surrounding area. Increase the distance of the torch gradually as the general area heats up and the repair cools, slowly pulling it back to apply less and less heat to the area while washing over a slowly-increasing area. This will slowly cool the manifold in a consistent pattern to avoid causing new stress cracks due to the thermo-dynamic expansion rate of the manifold material.

4

Begin removing the torch, then replace it in ever-increasing intervals once the torch has been worked back to about 18 inches from the area and the metal has lost all glow and has dropped in temperature so that the heat may be removed entirely.

5

File away any protruding brazing material from the mating face of the manifold. Hold the file flat and in plane with the side of the flange that did not break off. Judge the flatness of the repaired piece with the unbroken side. Remove material from the repaired flange if necessary to achieve flatness.

In an internal combustion engine, the exhaust manifold collects the products of combustion (exhaust gases) from two or more cylinders and conducts these to a single exhaust pipe.

Design

Typically made of stainless steel, cast-iron or heavy-gauge steel, the exhaust manifold directs exhaust gases from multiple cylinders to a single exhaust pipe. In so doing, the exhaust manifold also helps to minimize leakage of heat, air and gases. Copper gaskets connecting the manifold to the cylinder heads can be used to create a more airtight system, though these are not necessary.

Benefits

By minimizing the loss of heat, the exhaust manifold reduces the temperature under the hood. This helps to prevent overheating and damage to heat-sensitive parts while increasing power by reducing the temperature of the intake manifold. As gases move more quickly in higher temperatures, the exhaust manifold helps to increase the speed at which exhaust leaves the system.

Limits

As cylinders fire at different times, an ideal exhaust manifold would contain pipes of different lengths to ensure that exhaust gases from one cylinder have been cleared from the system before another fires (i.e., to prevent back pressure). Due to space limitations, however, exhaust manifolds typically contain short pipes of uniform length. Though compact, this design increases back pressure, subsequently increasing heat loss under the hood and reducing engine performance.

A vehicles intake manifold distributes the mixture of fuel and air to the engine cylinders. If the intake manifold is cracked or the mating surfaces are warped, this will cause the fuel/air to leak and the manifold must be replaced. The following instructions are general for removing and installing the manifold. The exact procedure can vary with each model, however, especially regarding the exact wires and lines connected to the manifold. It is very important that you have a manual written specifically for your model vehicle.

Removal

Because you are working on the fuel system, you need to depressurize the system. Remove the fuel pump relay from the fuse box and then start the engine until it stalls. You are also working with electrical connectors, so disconnect the negative cable from the battery. The manifold is also connected to the cooling system, so you must either drain the coolant or clamp off the coolant hose to the manifold before disconnecting it. Once all these precautions are done, disconnect all electrical connectors and lines attached to the manifold. This can include hoses from the radiator and air duct, the fuel lines, fuel rail and the fuel pressure regulators vacuum hoses, along with the electrical connectors to the crankshaft and camshaft position sensors, A/C compressor, alternator and starter. Now remove the nuts and/or bolts securing the manifold--use a torque wrench and make 1/4-turns until you can remove the bolts by hand. Remove the intake manifold.

Installation

Remove all traces of the gasket/sealant material from the engine cylinder heads with a gasket scraper, and make sure there is none on the manifolds surfaces as well. Clean those surfaces with acetone or lacquer thinner. If any material falls into the cylinder head intake ports, remove it with a vacuum cleaner. Clean up the bolts (or the manifolds studs) and apply a thin coat of engine oil to the threads. Apply a new gasket or RTV sealant to the manifolds mating surface. Make sure the intake ports, coolant holes and bolt holes are all properly aligned as you install the manifold in place and tighten the nuts/bolts. Now reconnect all the hoses, lines and electrical connectors to the manifold. Once everything is connected, you can unclamp the coolant hoses and reconnect the battery cable and fuel pump relay. Re-pressurize the fuel system by repeatedly turning on the engine for two seconds and then leaving it off for five. Start up the engine and see if oil or coolant leaks at the manifolds joints.

The Nissan 3.3 engines exhaust manifold collects exhaust from each of the valves and sends it through the exhaust pipe. The exhaust manifold must be in good condition to avoid harmful fumes from entering the cabin. If the vehicles exhaust manifold has a crack in it, replace it as soon as possible.

Instructions

1

Disconnect the negative cable from the battery using a wrench to loosen the nut on the terminal. Remove the heat shields from around the manifold using a wrench. Disconnect the EGR tube from the valve.

2

Unplug the electrical wire from the heated oxygen sensor by pulling it off. Disconnect the front exhaust pipes using a wrench to loosen the bolts. Remove the bolts from the exhaust manifold using a socket, ratchet and extension.

3

Remove the exhaust manifold with the catalytic converter still attached. Remove the catalytic converter from the manifold using a wrench. Attach the converter to the new manifold and tighten the bolts with a wrench.

4

Install the manifold to the engine and tighten the fasteners with a socket, ratchet and extension. Connect the front exhaust pipes using a wrench to tighten the bolts. Plug the electrical wire into the heated oxygen sensor.

5

Connect the EGR tube. Install the heat shields around the manifold and tighten the fasteners with a wrench. Connect the negative battery cable and tighten the terminal nut with a wrench.

Power Stroke engines appear in heavy Ford trucks manufactured since 1994. They use diesel fuel and typically have a turbocharger. The first Power Stroke engine had a displacement of 7.3 liters and was in production from 1994 to 2003. The exhaust manifold collects the exhaust gases from the cylinders, and each side of the engine typically has its own exhaust manifold. The most common reason for replacing the exhaust manifold is rust caused by the exhaust gases.

Instructions

1

Remove the cables from the negative terminals of both batteries with a socket wrench. This prevents anyone from accidentally starting the engine while you are replacing the exhaust manifold.

2

Access the right exhaust manifold from the top of the engine compartment. Bend the tabs on the attaching bolts for the right exhaust manifold, and disconnect the inlet pipe of the right muffler from the right exhaust manifold with a socket wrench.

3

Raise the vehicle and support it on jack stands. Access the left exhaust manifold from underneath the vehicle, and bend the tabs on the attaching bolts for the left exhaust manifold. Disconnect the inlet pipe of the left muffler from the left exhaust manifold with a socket wrench.

4

Clean the cylinder heads with a shop towel, and apply anti-seize compound to the threads on the new exhaust manifolds. Connect the new left exhaust manifold with a new gasket and locking tabs. Tighten the mounting bolts for the left exhaust manifold to 45 foot-pounds with a torque wrench. Bend the locking tabs over the bolt heads to secure the bolts.

5

Lower the vehicle and connect the new right exhaust manifold with a new gasket and locking tabs. Tighten the mounting bolts for the right exhaust manifold to 45 foot-pounds with a torque wrench. Bend the locking tabs over the bolt heads to secure the bolts.

6

Connect the cable to the negative terminal for both batteries with a socket wrench. Start the engine and correct any leaks in the exhaust system.

Removing an exhaust manifold from a six-cylinder Ford 300 engine is not difficult. This engine actually has two exhaust manifolds, one on the left and one on the right. If the gasket goes bad between the manifold and the engine block, you need to replace it. Likewise, if the manifold starts to crack, you will need to replace it. Removing the exhaust manifold yourself can save you money on labor charges at an auto-repair garage.

Instructions

Left Manifold

1

Open the hood and prop it safely with the support. Remove the oil dipstick bracket using a wrench. Remove the air cleaner unit from the carburetor by turning the thumbscrew and pulling the entire assembly away from the engine. Remove the servo bracket assembly using a wrench. Label the proper location of each of the spark plug wires with a marker and masking tape. They must go back to the same location that you took them off.

2

Pull each wire from the plug by grasping the boot and pulling it away from the spark plug. Disconnect the oxygen sensor wire by pulling it off the fitting. Lift the vehicle on the front end with the automobile jack. Place a jack stand under the vehicle near the jacking point and raise it to the frame. Crawl under the vehicle and disconnect the exhaust pipe from the exhaust manifold using a wrench. Remove the jack stand from under the vehicle. Lower the vehicle to the ground.

3

Remove the bolts attaching the exhaust manifold to the engine block using a socket set. Pull the manifold and gasket away from the engine block.

Right Manifold

4

Remove the air cleaner from the engine. Do this if you are removing the left exhaust manifold as well. Disconnect the transmission dipstick tube from the engine using a wrench to release the nut. Remove the Thermactor hose and the air tube bracket using a wrench. Label the spark plug wires with a marker and masking tape. They have to go back on the way they came off. Unplug the ignition coil and plug wires by grasping the boots and pulling them away.

5

Remove the spark plugs using a socket, ratchet and extension. Remove the heat shield using a wrench to loosen the bolts. Lift the automobile using the automobile jack. Support the vehicle by placing a jack stand under the vehicle near the jacking point and raising it to the frame. Crawl under the vehicle and disconnect the exhaust pipe from the exhaust manifold. Remove the jack stand from under the vehicle. Lower the automobile to the ground.

6

Remove the exhaust manifold from the engine using a socket and ratchet to loosen the bolts. Remove the inner heat shroud and EGR tube as an assembly from the cylinder head using a wrench.

An engines exhaust manifolds sole purpose is to route the dangerous gases produced by the engine to the vehicles exhaust pipe. The exhaust manifold attaches to the side of the cylinder head. Between the cylinder head and the exhaust manifold is a gasket designed to prevent exhaust leaks. Exhaust gaskets are known to fail given enough time. When this occurs, a clapping sound can be heard emanating from the engine, and exhaust gases can enter the interior of the vehicle. To repair the exhaust leak, the exhaust manifold must be removed. Even if the gasket does not leak, the manifold must be disconnected to either replace the exhaust system or to remove the engine from the vehicle.

Instructions

1

Lift the front of the vehicle with a floor jack using the vehicles frame as a lift point, then position two jack stands underneath the frame of the vehicle. Lower the vehicle onto the jack stands with the floor jack.

2

Disconnect the exhaust manifold from the exhaust pipe from underneath the vehicle. Exhaust manifolds typically utilize two bolts to secure the exhaust pipe to the manifold. Remove these bolts with a wrench, then pull the exhaust pipe away from the manifold.

3

Remove the exhaust manifolds retaining bolts from the engines cylinder head with a wrench. There is typically one exhaust manifold retaining bolt located on each side of every manifold pipe. For example, if there are four exhaust pipes on the manifold, there will usually be a total of eight retaining bolts.

4

Pull the exhaust manifold away from the cylinder head to remove it. A stubborn exhaust manifold can be dislodged from the cylinder head without damaging the manifold by tapping on the manifold with a rubber mallet.

Vortec engines have a swirl port in their combustion chambers, which allows the fuel and air to mix more readily. General Motors has manufactured the six-cylinder 4.3-liter Vortec engines since 1985, primarily for use in light Chevrolet trucks made before 1995. The intake manifold is the part of the engine, and delivers the fuel/air mixture to the cylinders. The procedure for removing the intake manifold is similar for all full-size Chevrolet trucks made from 1988 to 1995.

Instructions

1

Remove the cable from the negative battery terminal with a socket wrench. Drain the coolant in the radiator into a container, and seal the container for later use.

2

Disconnect the air cleaner and the distributor with a socket wrench. Detach the cables for the cruise control and accelerator from their respective brackets.

3

Remove the bracket for the air compressor, alternator and idler pulley from the intake manifold with a socket wrench. Detach the electrical wiring and vacuum lines from the intake manifold. Disconnect the exhaust gas recirculation valve, if your vehicle is so equipped. Remove the fuel line from the intake manifold.

4

Detach the heater pipe and upper radiator hose from the radiator. Disconnect the vacuum lines for the power brakes and exhaust gas recirculation valve, if your vehicle is so equipped. Disconnect the electrical wiring from the ignition coil.

5

Disconnect any remaining brackets and sensors from the right side of the intake manifold. Detach the electrical wiring harness on the right side of the intake manifold and push it out of your way. Remove the mounting bolts from the intake manifold with a socket wrench. Detach the intake manifold and its gaskets from the engine.