So Fix it

Catalytic converters, also called "cats," absorb exhaust heat, and should, ideally, be as close as possible to the exhaust manifold for emissions compliance. This placement varies by make and model and can have a significant impact on performance.

The Y-Pipe

V-type engines often use y-shaped pieces of tubing to join the cylinder banks exhaust streams before entering into the converter. Converters are often bolted right to the back of this Y-pipe.

Direct Connection

Many manufacturers, such as Honda and Toyota, are becoming known for bolting the catalytic converters right to the exhaust manifold outlet, with nothing in between.

Down Tubes

Most turbocharged engines use a down tube, which is a smooth piece of tubing that allows a turbos exhaust flow to move away smoothly, before encountering the restrictive cat.

Oxygen Sensor

All new vehicles have an oxygen (O2) sensor somewhere between the exhaust manifold and cat. This works in conjunction with an after-cat O2 sensor to notify the engine control computer of any converter malfunction.

Exhaust Brakes

Large diesel trucks often have a large valve in between the cat and manifold, known as an exhaust or "Jacobs" brake. When closed, these valves create back pressure in the engine and allow a driver to control downhill acceleration without using the foot brake.

An engines exhaust manifold routes exhaust gases from the engine to the vehicles exhaust system. Without the exhaust manifold, hazardous exhaust fumes can reach the interior of the vehicle. Installation of the exhaust manifold is usually the final step of the engine installation process, but installation is also necessary when an exhaust manifold gasket is replaced. Thankfully, installing an exhaust manifold is a straightforward process.

Instructions

1

Ensure that the exhaust manifolds mating surface is free from old gasket deposits to begin the installation process. Old exhaust manifold gaskets rarely leave gasket deposits, but if any deposits are present they should be scraped away with a gasket scrapper.

2

Place a new exhaust manifold gasket over the manifolds mating surface. Do not apply gasket sealer to this gasket.

3

Position the exhaust manifold with its gasket against the portion of the head where the manifold attaches, then place one exhaust manifold bolt through one end of the manifold and into the head. Turn this bolt only until it begins to grasp the threads within the head.

4

Insert another manifold bolt into the opposite side of the exhaust manifold and turn this bolt only until it begins to grasp the threads within the head.

5

Insert the remaining exhaust manifold bolts through the manifold and into the head.

6

Tighten each exhaust manifold bolt to the required torque specifications with a torque wrench to complete the installation. Refer to the vehicles specifications manual for this torque setting.

The intake manifold for an delivers fuel and air to the engine in a precise ratio. International Harvester made an eight-cylinder 6.9-liter diesel engine from 1982 until 1987. This engine commonly appears in Ford F series trucks during this period, especially F-250 and F-350 models. The removal of the intake manifold in a Ford truck with a 6.9-liter engine requires you to remove the injection pump and other components to access the intake manifold.

Instructions

1

Remove the cables from the negative terminals of both batteries with a socket wrench. Disconnect the air cleaner from the intake manifold. Plug the air intake of the intake manifold with clean shop rags to keep debris out of the engine.

2

Detach the electrical connectors from the injection pump. Remove the bracket for the fast idle solenoid with a socket wrench, so you can access the mounting bolts for the injector pump. Disconnect the cables for the cruise control and accelerator from the throttle lever, if your vehicle is so equipped. Remove the bracket for the accelerator cable and push it out of the way.

3

Remove the fuel lines, in the elbow inlet and fitting adapter from the injection pump with a socket wrench. Rotate the injection pump out of the way, and disconnect the fuel lines from the injection nozzles. Cap all fuel lines and injection pump fittings with fuel system protective cap set T83T-9395-A to keep debris out of the fuel system.

4

Disconnect the retaining nuts from the the injection pump with tool T83T-9000-B. Detach the injection pump from its adapter, and remove the injection pump from the engine.

5

Disconnect the fuel return lines from the rear injection nozzles on the number seven and number eight cylinders. Detach the fuel return line on the fuel tank, and disconnect the electrical wiring harness from the engine. Remove the ground cables for the engine wiring harness from the left cylinder head.

6

Remove any additional components necessary to access the intake manifold on your vehicle. Disconnect the mounting bolts for the intake manifold with a socket wrench, and remove the intake manifold from the cylinder heads.

Mazda completely redesigned the Miata for the 1999 model year with a completely different look. Many enthusiasts were relieved that Mazda left well-enough alone underneath. The 1999 Miata still used the same 1.8 liter four-cylinder engine that was used in the first-generation cars. The stock single-exhaust pipe is attached to a cast-iron exhaust manifold that is bolted to the engine. A cracked manifold will allow exhaust gases to enter the passenger compartment and should be replaced immediately.

Instructions

1

Spray penetrating fluid on the heat shield retaining bolts, the exhaust manifold-to-engine block bolts, the EGR pipe fitting and the exhaust pipe-to-manifold bolts. Allow the fluid to soak in overnight, if possible.

2

Loosen and remove the nut and bolt that secures the factory shock tower brace to the drivers side shock tower with a socket and ratchet. Lift the brace straight up to allow access to the exhaust manifold. Skip this step if your car did not come equipped with the shock tower brace.

3

Loosen and remove the retaining bolts for the windshield washer reservoir with a socket and ratchet. Lift the tank straight up and move it to the side -- as far as the connections will allow -- to provide access to the heat shields on the exhaust manifold. Skip this step if your car is not equipped with anti-lock brakes.

4

Loosen and remove the retaining bolts on the air cleaner housing on top of the engine with a socket and ratchet. Loosen the clamp that secures the air intake hose to the air cleaner housing with a Phillips screwdriver. Pull the hose off the housing. Push the housing to the side to allow access to the heat shields and exhaust manifold. Cover the ends of the intake hose and its fitting on the air cleaner housing with clean rags to prevent foreign debris or dirt from entering.

5

Loosen and remove the retaining bolts that attach both of the heat shields to the exhaust manifold with a socket and ratchet. Remove the heat shields from the manifold and place them aside.

6

Remove the EGR tube retaining bolts on the exhaust manifold and the intake manifold with a socket and ratchet. Loosen and unscrew the fitting that attaches the EGR tube to the end of the exhaust manifold with a tubing wrench.

7

Loosen and remove the three bolts that attach the exhaust pipe to the exhaust manifold with a wrench.

8

Loosen and remove the exhaust manifold-to-engine block retaining bolts with a socket and ratchet. Work slowly to avoid damaging or breaking off the bolts in the block. Stop and apply more penetrating fluid, if one or more of the bolts seem very tight. Allow the fluid to soak in for several hours, if possible.

9

Pull the manifold away from the engine block. Note that the water pipe bracket will slide off one of the manifold mounting studs as you remove the manifold. Do not allow the water pipe to move rearward. Remove the manifold from the engine bay. Remove the exhaust manifold gasket from the engine block. Scrape away any gasket residue on the mounting surface with a gasket scraper.

10

Position a new exhaust manifold gasket over the mounting studs on the engine block. Position the replacement exhaust manifold over the mounting studs. Push the water pipe bracket over the stud that it was originally attached to. Replace and tighten the manifold retaining bolts to between 29 and 33 foot-pounds with a torque wrench.

11

Replace the exhaust pipe-to-manifold bolts and tighten them to between 32 to 44 foot-pounds. Tighten the EGR tube fitting into the end of the manifold to between 24 and 34 foot-pounds. Replace and tighten the remaining EGR tube retaining bolts.

12

Replace the heat shields and tighten the retaining bolts. Place the air cleaner housing into position and tighten the retaining bolts. Remove the rags from the intake hose and air cleaner housing. Push the intake hose onto the housing and tighten the hose clamp.

13

Replace the windshield washer reservoir -- if your car has ABS -- and tighten the retaining bolts. Push the shock tower brace -- if your car is so equipped -- into position and replace and tighten the retaining bolt and nut.

The intake manifold is the part of your engine that distributes combustion substance and/or air consistently throughout the intake ports on your cylinder heads. Without the intake manifold, your engines performance would suffer, and you would lose engine efficiency. One company that makes intake manifolds is Motor Parts (Mopar), a subsidiary of the Chrysler Group LLC. It makes intake manifolds for Ram, Jeep, Chrysler and Dodge vehicles, but you can only purchase them from authorized dealers.

Mopar 426

The Mopar 426 Hemi Crate Engine gives you up to 486 foot-pounds of torque, and it comes with a dual quad intake manifold. The intake manifold in this engine is made of aluminum, making it fairly light. It is designed for race cars or for those who just want more road power. This manifold also has a dual plane M1, and you can convert this manifold so that its compatible with AVC carburetors. It is, however, already compatible with large port and Holley carburetors. The engine gives you up to 465 horsepower, and horsepower generally equals between 735.5 and 750 watts. The Mopar website indicates that this engine is an updated version of the 426 design, but the new design provides you with a more efficient and potent engine.

Six Pack

The Six Pack intake manifold is for 413, 440 and 426W engines. It is made of aluminum, and it features high torque and horsepower, allowing you to go from the idle position to approximately 6,000 revolutions per minute. It is a dual plane intake manifold and has rectangular ports. These ports allow you to use this intake manifold for both small and large applications. According to the Mopar website, you can use this intake manifold for both "street and strip applications."

Cross Ram

The Max Wedge Cross Ram Intake Manifold works with any type of RB engine that uses the Max Wedge cylinder heads, especially the Dodge Ram. This manifold is made of aluminum, and it is a single plane M1 type of manifold. The Max Wedge Cross Ram Intake Manifold increases the total airflow through the manifold by nearly 20 percent, according to the Mopar website. The makers of this manifold designed it to work with all types of Holley 850 cubic feet per minute carburetors that have a 2-1/8 inch exhaust header. According to the Mopar website, this intake manifold also increases your engines power, and the engine provides you with 505 horsepower.

The exhaust manifold is a large metal block bolted to the side of the engine, and it connects the exhaust pipe to the main engine block. To locate the exhaust manifold, trace your exhaust pipe to where the round pipe bolts to a two-bolt connection near the engine. The solid structure to which the pipe is bolted is the exhaust manifold. Installing a manifold requires careful torquing of the bolts.

Amount of Torque

Every vehicle has different levels of torque necessary to properly tighten its bolts. The standard is to use 20 to 30 foot-pounds of torque. Older engines often fall on the lighter side of the equation, so use 15 to 20 foot-pounds of torque if your engine is 15 years old or older. Some manifolds house different sensors and plugs, such as a check valve or exhaust plug. The different elements require less torque than the bolts on the manifold. Use between 10 and 17 foot-pounds of torque for those elements. The precise torque for your vehicle can be identified in the vehicle-specific repair manual, available from an auto parts retailer.

Torque Sequence

Clean off any used gasket material, and install a new gasket when you take the manifold off the vehicle. Torquing the bolts properly requires following a set pattern. The pattern helps the new gasket sit correctly against the engine blocking leaks. Hand-tighten all bolts initially. Torque the bolts in sequence to half the amount of torque necessary. Start with the middle bolts, and work your way toward the edges one bolt at a time. Repeat the process using the full torque necessary.

Additional Information

In most vehicles, the manifold is covered by a heat shroud, which is a simple piece of formed aluminum. The metal acts as a heat damper to prevent excessive heat from bouncing around in the engine. You must remove the heat shroud before working on the manifold. When installing the shroud, use 10 to 12 foot-pounds of torque. You also should inspect the length of the exhaust pipe for damage. When servicing the exhaust, you should disconnect each bolted connection, clean the surface of the connection and install new gaskets at each joint. You can unbolt each connection and separate the joint by several inches without removing the unit from the vehicle.

Having a manifold leak in your vehicle can cause it to have performance problems. Making sure that the leak gets fixed is important if you want your vehicle performing at its peak. Because the intake manifold is primarily responsible for distributing the mixture of both fuel and air to each of the engines intake ports, fixing these types of leaks is paramount when trying to get the most out of your engine.

Instructions

1

Check your vehicle to see if theres any oil leaking from the manifold. Identify where the leak is.

2

Disconnect the battery. Remove the nylon fuel rail and the air ducts. Once the fuel rail is removed, press the wires of the injector connectors with your fingers in order to detach them. Use a screwdriver to help make the rubber rings loose. This will aid in removing them easier.

3

Use a socket to take the throttle cables, alternator brace and throttle cable cover off. You must also remove from the intake manifold, the throttle body. Once this has been accomplished, you will need to loosen the two nuts that are attached to the EGR pipe and detach that as well. When you do this, youll find a gasket on the EGR pipe, but leave it there for later use.

4

Inspect the manifold of your engine. Remove any gaskets that seem to be loose or broken, and replace them. Clean existing gaskets with WD-40, and make sure theyre free of debris by wiping them with the cloth. Replace all of the parts you just took off. This should fix the leak. If it does not, take your vehicle to a professional.

The intake manifold is sealed to the cylinder heads of an engine to prevent coolant leaks from occurring. If coolant escapes, it can run all over the engine and other parts, which can lead to other vehicle problems. Its beneficial to have information regarding why engine manifold gaskets go bad.

Causes

Leaks are often the reason that engine manifold gaskets go bad. Corrosion can wear the gaskets metal over time, which causes the manifold gaskets to lose their leak-free seal. A metal epoxy applied with extreme heat can repair the gasket and allow it to seal efficiently once again.

Types

There are several types of vehicles with engines that are known for having manifold gaskets that are prone to go bad. General Motors makes several of these engines, including V8 engines such as the 5.0L and 5.7L.

Time Frame

Manifold gaskets can last in good working order on a vehicle for many thousands of miles before they go bad. Some vehicle engines are equipped with plastic manifold gaskets that may not last as long. Plastic gaskets can perform well to around 70,000 miles before they go bad and need replacing.

A head gasket seals an engine as well as the pathways of oil and coolant within the engine. An intake manifold gasket seals the cylinder heads and the intake manifold together. Information on these parts can be beneficial as they can both experience leaks leading to other problems if left unchecked.

Manifold Gasket Leak

A leak in the intake manifold gasket can lead to coolant running down the sides of a vehicles engine. Some vehicles have become well known for springing leaks in their intake manifold gaskets. These vehicles, however, are usually equipped with plastic manifold gaskets which tend to fail sooner than other gaskets.

Head Gasket Leak

A head gasket can leak either coolant or compression. Coolant leaks in a head gasket will be discovered fairly quickly due to the fact that an engine will run hot as a result. Although compression leaks cause engines to lose a lot of their power, they will not prohibit you from continuing to drive the vehicle.

Considerations

Some motors are prone to coolant leaks in their intake manifold gaskets. There are also some vehicles which have motors prone to head gasket failure. Review consumer guides and other forums to determine if a particular vehicle is subject to head gasket failure more often than others.

A vehicles air conditioning system is an important component in hot weather. The 134A refrigerant, and its resulting manifold pressure, provide a way to maintain the coolest air for the vehicles occupants.

Function

Run through a cars air conditioning system, 134A refrigerant acts as the cooling conductor for the air. Periodically, the refrigerant can become low, resulting in warmer air through the system and into the vehicle.

Features

While recharging the system with refrigerant, the 134A manifold gauge pressure should be monitored so the proper amount of refrigerant is used. Two different pressure gauges can be used, either low or high. For a low pressure gauge, a reading of 25 pounds per square inch (psi)to 40 psi is optimum. On the other hand, a high pressure gauge should read between 225 psi and 250 psi.

Considerations

If the refrigerant becomes low after a few months of circulation, there may be a leak in the system. AA1 Car recommends having the leak repaired before trying to recharge the system again.

Oil on the exhaust manifold or blue smoke spewing out of the tailpipe is commonly caused from a compromised gasket or cracked exhaust manifold. The head gasket is the main seal protecting the engine cylinders from engine oil. A compromised head gasket or O-ring will allow oil into the cylinders and exhaust manifold piping.

Exhaust Manifold Function

The exhaust manifold is secured directly to the individual engine cylinder ports. Exhaust gases expel from the combustion chamber into the exhaust manifold before moving towards the tailpipe. There must be an airtight seal between the manifold pipes and the cylinder ports.

Blue Smoke

Blue exhaust smoke may be coming from your tailpipe. Blue smoke indicates oil in the cylinder ports and then exhaust manifold -- a sign that a gasket or O-ring protecting the cylinders from oil has failed.

Diagnosing A Compromised Exhaust Manifold

Oil commonly enters the inner portion of the exhaust piping after leaking through the cylinder ports but it is possible for oil to find its way onto the external portion of the piping. This occurs one of three ways: a crack in the manifold piping, a compromised exhaust manifold gasket or a blown oil seal. In any case, an engine oil seal has failed.

For many, the need to find car exhaust manifold leaks follows a failed emissions test. You might also hear a rumble when starting your car or while it runs cold. Thankfully, finding out whether you do, in fact, have a leak is a fairly easy process.

Instructions

1

Test your car shortly after starting it. You may be able to hear and feel the leak more easily while it is still cold. You also lower the risk of burning yourself.

2

Sniff around for exhaust. This is the least definitive way to test your manifold for leaks, but it may be a sign. Carbon monoxide, which is what is released by your exhaust system, has no smell.

3

Listen to your car. Most exhaust manifold cracks or leaks will cause a ticking noise, especially when your car is running cold. There may even be a noticeable vibration that goes along with the noise.

4

Use a stethoscope to listen to the manifold closely. You should be able to determine the location of the leak if there is one. If you dont have a stethoscope, use a hose or tube to localize sound.

5

Check your manifold physically. If you can get it out of your car and manually inspect the part, you may be able to determine warping or cracking. Since this requires removing parts from your engine, you may want to consult a mechanic.

6

Look for damage around the exhaust ports. Discoloration or burnt paint often signifies a leak. Burned spark plugs, boots or valves indicate a leak as well. If you notice this kind of damage, have your manifold fixed immediately to avoid more serious fires.

7

Take your car in for an emissions test, even if it is not due. Most leaks reduce the oxygen output and will cause the car to fail the test. If your manifold passes inspections, you may just need to have it straightened out due to warping.