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You Should Know This About Your Car Exhaust Manifold

The exhaust manifold constitutes to be among the first components of your vehicle's exhaust system. It is attached to your vehicle's engine and captures the emissions produced by it. The exhaust manifold receives the air/fuel mix from your car engine's various cylinders. Whether you have four, six, or eight cylinders, it collects the fuel/air mixture from each one. Not only does the exhaust manifold collects all the burnt engine gases, but it also uses its extremely high temperature to totally burn any unused or incompletely burnt gases. Read along to understand more about your car’s exhaust manifold and its working mechanism better.

What Is Car Exhaust Manifold?

The leading role in a car or truck’s exhaust system is played by the vehicle’s exhaust manifold. It connects to each exhaust port on the engine's cylinder head, and it channels the hot exhaust gases down into one simple exhaust pipe. It also helps in preventing the toxic exhaust fumes from escaping into the vehicle and harming the passengers. Hence, it is always best to have your exhaust manifold in good working condition.

There are two exhaust manifolds attached to the average V-shaped engine. Each exhaust manifold is attached to one cylinder bank in the case of a V-type engine or a flat engine. Cylinder banks are lines of cylinders arranged in a particular style in multi-cylinder engines. Most of the inline engines have one exhaust manifold which is known as a rotary engine. There is usually one exhaust manifold present whereas the turbocharged models will have downpipes on the side, where the turbo is hot. The exhaust manifolds are usually made of cast iron or welded tubular steel.

If you are willing to know more about Car Exhaust Manifold, then you should visit our “What Is An Exhaust Manifold?” section.

How Does My Car Exhaust Manifold Work?

The first part of your vehicle’s exhaust system is the exhaust manifold. It is attached to your vehicle’s engine and gathers your engine’s emissions. The exhaust manifold will get the air/fuel mixture from the multiple cylinders in the engine of your vehicle. Apart from receiving all of the burnt engine gases, it also completely burns the remaining or incomplete burnt gases due to its very high temperature. Also, the manifold houses the first oxygen sensor in your exhaust system to check the amount of oxygen that enters the system. The oxygen sensor will carefully look at the amount of oxygen and will inform the fuel injection system to raise or lower the amount of oxygen used in the fuel/air mixture which helps to power the engine. Usually, the exhaust manifold functions as a funnel and helps in collecting all of the engine’s emissions. Once they are set properly in place and are completely burnt, the emission is sent into the rest of the exhaust system.

How To Choose The Right Exhaust Manifold ?

What Are The Common Car Exhaust Manifold Problems?

The frequent problems you might experience with the faulty exhaust manifold are:

  • Cracked Exhaust Manifold- An exhaust manifold can be cracked or broken most often because of one of two things - The very first reason can be heat cycles or age. As time goes by the manifolds won’t be able to take the heat anymore and so they start forming cracks. These exhaust manifold cracks will eventually turn into small holes, which doesn’t help any further. The other reason can be corrosion and rust which can be caused because of road salt, dirt, and moisture.
  • Broken exhaust system hangers- The whole exhaust system is held up with a bunch of hangers. If these hangers break, or if the rubber donut exhaust hangers tear apart, the whole responsibility of bearing the weight will fall upon the exhaust manifold. The exhaust manifolds aren’t built for one such action. Even before they could bear the weight, they will eventually fall off.

Which Tools Do I Need To Repair My Car Exhaust Manifold?

Do you enjoy repairing your car on your own? Thinking of opening up your own car body shop? It is a great business opportunity if you love cars and possess a good work ethic. Now if you want your shop to be successful, then you will require a combination of effort and car mechanic training. And of course, the correct equipment would upgrade your speed and make your repair work easy. If you have the right tools, then you can easily meet the demands of today's car body structures. Here are some of the most essential tools which you might need to repair your car exhaust manifold:

  • Boxed end wrench(s) or ratchet wrench set(s)
  • Can of carb cleaner
  • Clean shop rags
  • Coolant container (extra coolant to refill radiator)
  • Flashlight or droplight
  • Impact wrench and impact sockets
  • Light grit sandpaper, steel wool, and gasket scraper (in some cases)
  • Penetrating Oil (WD-40 or PB Blaster)
  • Replacement exhaust manifold, new gasket
  • Safety equipment (safety glasses and gloves)
  • Torque wrench

Which Top Brands Exhaust Manifold Parts Should I Choose?

For a vehicle owner’s choice, the brands really matter a lot. You might pay a premium for a specific car part brand, over time, as it has created a perception of quality, stability, and trust. There are some leading car parts brands that are more than just products or services as they give rise to memories and emotions related to the quality. So have a look at some top brands for Exhaust Manifold.

  • Dorman (OE Solutions) Exhaust Manifold
  • Flowtech Exhaust Manifold
  • Dorman (Hd Solutions) Exhaust Manifold
  • ATP Professional Autoparts Exhaust Manifold
  • BD Diesel Exhaust Manifold
  • Crown Automotive Jeep Replacement Exhaust Manifold

To know more about top brand exhaust manifold, visit our “Which Popular Brand Exhaust Manifold Should I Choose?” section.

What Are The Steps Of Changing My Car Exhaust Manifold?

Here are a few steps as to how you should change the exhaust manifold.

Step 1

  • Remove the vehicle's battery.
  • Disconnect the positive and negative cables so that the power is disconnected from all electronic components before you remove any parts.

Step 2

  • Now take away the engine cover. Vehicles manufactured after 1991 will have an engine cover that covers access to the exhaust manifold.
  • These engine covers are bolted with a series of snap connections and bolts.
  • Now remove the bolts with the help of a ratchet, socket, and an extension, and finally remove the engine cover.

Step 3

  • Now remove the engine components in a similar way to the exhaust manifold.
  • Each vehicle has different parts that are in the way of the exhaust manifold and it has to be removed before you try to remove the exhaust heat shield.
  • You can always check your vehicle service manual for exact steps on how to remove these auto components.
  • The heat shield will have different sizes, shapes, and materials in which it is constructed, but usually covers the exhaust manifold on domestic as well as import vehicles.

Step 4

  • Now you will have to remove the heat shield.
  • For most of the cars, trucks, and SUV's manufactured after 1980, US automotive laws have made strict that a heat shield has to be installed over the exhaust manifold to minimize the potential of vehicle fires caused by burning fuel lines, or other materials which come in contact with more heat which is produced by the exhaust manifold.
  • To remove the heat shield you'll have to unscrew two to four bolts which are either on the top or to the side of the exhaust manifold.

Step 5

  • Spray the penetrating fluid on the exhaust manifold bolts or nuts.
  • As the vehicle produces excessive heat, there are chances that the bolts which hold this component to the cylinder head might get fused together or rusted.
  • In order to avoid the breaking of studs, it is best to apply a liberal amount of penetrating oil on top of each nut or bolt which holds the exhaust manifold on the cylinder heads.
  • As soon as you complete this step, you will also have to complete the step where the exhaust manifold connects to the exhaust pipes.
  • Typically, there are three bolts that connect the exhaust manifold to the exhaust pipes.
  • Allow both the bolts and nuts to soak by spraying the penetrating fluid on both sides and in the meanwhile remove the top portion.
  • Remove the exhaust manifold with the help of a socket, extension, and ratchet. Also, you can use them to remove the bolts if you have room in the engine compartment.

Step 6

  • Now take away the exhaust manifold from the cylinder head.
  • Once you are sure that the bolts have been soaked for about 5 minutes, take away the bolts that hold the exhaust manifold tightly to the cylinder head.
  • Based on the vehicle you are working on, there might be either one or two exhaust manifolds especially if it's a V-style engine.
  • Remove bolts and when you fix the new manifold, you'll have to tighten them in a specific order.

Step 7

  • Now take away the exhaust manifold from the exhaust pipe.
  • Once you take away the bolts which hold the exhaust manifold to the cylinder head, you will have to go underneath the vehicle to remove the bolts and nuts which hold the exhaust manifold to the exhaust system.
  • Most often you will find one bolt on one side and a similar size nut on the other side.
  • With the help of a boxed end, the wrench tool holds onto the bolt and with the help of a socket removes the nut.

Step 8

  • Now you will have to remove the old exhaust manifold gasket.
  • On most vehicles, the exhaust manifold gasket will be of metal type and will easily come off the cylinder head studs once you remove the exhaust manifold from the vehicle.
  • Now you can remove and throw away the old exhaust manifold gasket.

Step 9

  • The exhaust ports on the cylinder head have to be cleaned.
  • It's very essential to remove the adequate carbon build-up on the exhaust ports on the inner side of the exhaust port before you fix a new exhaust manifold.
  • With the help of a can of carb cleaner, spray onto a clean shop rag and then the insides of the exhaust ports have to be wiped until the port looks clean.
  • Additionally, with the help of some steel wool or lightweight sandpaper grit, you can gently scrub the outsides of the ports to remove any pits or residue.
  • On most vehicles, you have to fix the bolts by holding the exhaust manifold onto the cylinder heads in a specific pattern.
  • You can also refer to the vehicle's service manual for exact instructions and recommended torque pressure settings for fixing a new exhaust manifold.

If you are still confused about which type of car Exhaust Manifold you should buy, then you can visit our Ultimate Exhaust Manifold Buying Guide. You should always look for the warning signs of a bad Exhaust Manifold and replace them at the earliest you can. With us, you can find Exhaust Manifold at the most economical cost.

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John Framigllia
Technical Writer
Our technical writer is known for simplifying automotive parts and services. Intuitive with various vehicles and manufacturers, he knows how to simplify complicated problems.