Repair And Fix it

The exhaust gas recirculation valve, or EGR valve, is part of the Mercury Sables emissions control systems. EGR valves, which were introduced in the 1970s, are now included on all automobiles in the United States.

Purpose

The EGR valve, usually located on the intake manifold, reduces oxides of nitrogen (NOx) that form in internal combustion engines when temperatures reach 2,500 degrees Fahrenheit or more. Nitrogen and oxygen combine to form NOx, a component of smog.

Function

As its name implies, the EGR valve recirculates exhaust gases back into the combustion chamber. Because the exhaust gases cannot be burned again, the result is cooler temperatures in the combustion chambers---several hundred degrees cooler. This reduces the production of NOx.

Performance

The creation of the EGR valve has enabled auto engineers to design more aggressive timing for engines, increasing efficiency and, as a result, improving fuel economy. A malfunctioning EGR valve, however, leads to engine ping and knocking.

A Chevy exhaust gas recirculation (EGR) valve is a necessary part of the cars emissions system. It works by rerouting some of the exhaust gases back into the intake manifold rather than into the atmosphere.

Types

There are several types of EGR valves with the same function but different modes of operation. Older EGR valves are purely mechanical and run on vacuum; on many newer Chevrolet and other GM models, the valve is controlled entirely by computer. This type uses multiple solenoids to open the valve in response to input from the cars computer, opening and closing the valve to allow exhaust gas flow.

Operation

Whether the EGR valve uses vacuum or electronic control, it opens when exhaust gases reach a certain temperature or level of backpressure. When the EGR valve opens, some of the exhaust is rerouted to the intake manifold. Since it is less combustible than the air-fuel mixture in the manifold, the temperature drops.

Functions

The main function of an EGR valve is to lower the amount of nitrogen oxide a car releases into the atmosphere. A failed EGR valve prevents a car from passing emissions testing, if required. The valves secondary function is to lower the temperature in the intake manifold.

The EGR, or exhaust gas re-circulation, valve is a key part of your vehicles exhaust system. The EGR valve is responsible for making your vehicle run efficiently by optimizing fuel intake. The EGR valve re-circulates exhaust back into the engine. The first sign that your EGR valve may need to be replaced or cleaned is when the vehicle starts to idle roughly or does not accelerates as quickly. You can check to see if your EGR valve needs replacement or cleaning yourself, saving yourself a trip to the shop.

Instructions

How to Check a Faulty EGR

1

Put the car in park and engage the emergency brake. Start the vehicle and let it warm up for 15 minutes.

2

Pull on the hood release cable inside the vehicle to open the hood. Locate the EGR valve on the engine manifold. You may want to er to your vehicles manual for exact location.

3

Locate the EGR plunger mechanism, which controls the exhaust gasses being re-circulated into the vehicles engine. The plunger is located on the outside of the EGR valve.

4

Check the EGR plunger for any malfunctions by having someone rev the engine. If the plunger opens and closes quickly, the EGR valve is good. If the plunger does not open or close, or opens and gets stuck, the valve is faulty and should be cleaned or replaced.

The EGR, or exhaust gas recirculation, valve is a small metal disc bolted to the intake manifold near the carburetor on GMC trucks and vans. The EGR valve draws exhaust gases from the exhaust system and reintroduces them into the intake manifold. Introducing exhaust gases into the combustion chamber helps lower the combustion temperature of the engine, which in turn helps reduce the amount of harmful oxides of nitrogen (NOx) produced by the engine.

Instructions

Removing a GMC EGR Valve

1

Remove the air cleaner housing by unscrewing the wing nut on top of the air cleaner lid and lifting the air cleaner housing straight up until you clear the threaded rod.

2

Locate the EGR valve. It will be bolted to the intake manifold close to the carburetor.

3

Label and disconnect the vacuum line attached to the top of the EGR valve by pulling it off.

4

Remove the bolts that secure the EGR valve to the intake manifold.

5

Lift the EGR valve straight up to remove it from the intake manifold.

6

Use a flat razor blade to clean any gasket material of the EGR valve mounting surface.

7

Inspect the passages below the EGR valve, and use a flat blade screwdriver to clear away any carbon deposits.

8

Vacuum the area around the EGR valve mounting surface. Make sure none of the carbon deposits or loose gasket material is left behind. You dont want it to get sucked into the engine.

Installing an EGR Valve on a GMC

9

Place a new gasket on the EGR valve mounting surface.

10

Lower the new EGR valve into position on the intake manifold.

11

Reinstall the bolts that connect the EGR valve to the intake manifold.

12

Reconnect the vacuum line that attaches to the top of the EGR valve.

13

Reinstall the air cleaner housing by lowering it over the threaded rod above the carburetor and reinstalling the wing nut that secures it.

The exhaust gas recirculation (EGR) valve in your 2000 Toyota RAV4 is an exhaust intake regulator attached to the intake manifold of the engine. First introduced in the early 1960s, it regulates the mixture of fuel and exhaust (oxygen) entering into the engines combustion chambers. It operates by allowing measured amounts of exhaust to enter the combustion chamber, thus reducing the temperature within the chamber during combustion. It has become a vital part in improving fuel efficiency and reducing smog.

Instructions

1

Open the hood and locate the EGR valve, which is mounted on the left-rear of the intake manifold near the firewall. Leave the battery plug in, but use precaution not to contact the posts with any tools.

2

Disconnect the air intake tube leading to the inside-left fender well and attached to the intake manifold. This will provide for better access for replacing the EGR valve.

3

Unplug the single-prong electrical connection from the EGR valve by hand. Disconnect the rubber vacuum tube and inspect both of these parts for excessive wear or cracking. Replace these parts as necessary.

4

Remove the two EGR mounting bolts located on the valve using a socket wrench. Gently tap the valve to break the seal using a hammer or rubber mallet. Remove the old EGR valve and scrape away the old gasket using a paint scraper. Be careful not to allow any debris to enter the engine block.

5

Apply a thin bead of high-temperature-resistant gasket sealer onto the new gasket. Place the gasket with sealant down, directly onto the manifold opening. Do not to disturb the gasket placement, which can cause a void. Be sure that the mounting bolt holes are properly aligned so that the replacement valve will seat and mount properly.

6

Carefully install the new EGR valve into the manifold opening. Secure the valve in place with the two mounting bolts. Reattach the rubber vacuum tube and the single-prong electrical connection. Reconnect the air intake tube.

7

Disconnect both battery cables using a crescent wrench, which will reset the electrical system and check-engine light indicator. Keep the battery disconnected for at least six hours before reconnecting it. Then reconnect the battery, start the engine and check to see if the check-engine light remains off. Test the repair by turning the vehicle off and on several times while observing if the check-engine warning light comes on.

The Exhaust Gas Recirculation (EGR) valve in your Ford Explorer is an exhaust regulating device attached to the intake manifold of the engine. It was first introduced to the United States in the 1960s and has continued to progress in improving fuel efficiency and reducing smog. It works by allowing small measured amounts of exhaust to enter the combustion chamber (pistons), thus reducing the temperature in the chamber. A malfunctioning EGR valve remains open and causes the temperature in the pistons to increase, allowing nitrogen oxide (smog forming emissions) to enter the atmosphere. Replacing the EGR valve in the Ford Explorer is a moderately easy repair to perform.

Instructions

1

Raise the hood and locate the EGR valve, which is attached to the right rear on the intake manifold near the firewall. The intake manifold is attached to the side of the engine block.

2

Disconnect the single-prong terminal electrical connection that plugs into the EGR valve sensor. Detach the black rubber vacuum tube which plugs into the EGR valve. Inspect the tube and electrical connection for cracking and excessive wear. Replace these parts as necessary.

3

Take out the two mounting bolts located on the top and bottom sides of the valve. Detach the old valve from the manifold and gently tap it using a hammer to break the seal. Scrape off the old gasket using a paint scraper, being careful not to allow any debris to enter the manifold.

4

Apply a thin coat of gasket adhesive to the new gasket using your finger and place it onto the manifold. Make sure the bolt holes are properly aligned so that the new EGR valve will seat properly.

5

Insert the new replacement EGR valve into the manifold opening being careful not to damage the EGR valve sensor attached on the top of the EGR valve. Secure the replacement EGR valve in place using the two bolts and reattach the single-prong terminal wire.

6

Disconnect the battery and wait 4-6 hours to reset the check engine light indicator. Reconnect the battery and see if the check engine light comes on again.

The first EGR valves were installed in engines in 1973, and these valves are still a staple in nearly all engines in 2010. The EGR valve is one of the many components used to control emissions. EGR is an acronym for "Exhaust Gas Recirculation."

Function

The main function of the EGR valve is to reduce the amount of nitrogen oxides (NOx) released into the air. The EGR valve prevents the release of NOx by recirculating cooled exhaust gases into the combustion chamber.

Effects

The EGRs cooling effect keeps the combustion chamber below 2800 degrees Fahrenheit. This temperature reduction limits the chemical reaction between nitrogen and oxygen, thus reducing NOx emissions.

Mechanics

Pre-electronic vehicles had vacuum-controlled EGR valves, while cars from 1996 and later use an electronic EGR. The mechanics of either valve are exactly the same. At idle, the EGR is fully closed and remains closed until warm-up. After warm-up, the EGR slowly opens as the engine speed increases, providing a cooling effect as the stress on the engine builds.

The Infiniti G20 was last produced for the 2002 model year. The car, like all modern cars, came with an EGR, or Exhaust Gas Recirculation, valve. This valve regulates fuel vapor and keeps your emissions system in check, making the G20 operate more efficiently. If the EGR valve is not functioning, youll need to disconnect it from the G20 so you can replace it with a new one. Do not, under any circumstances, operate the G20 without an EGR valve in place. This can cause engine damage.

Instructions

1

Turn off the G20s engine. Open the hood. Inspect the engine compartment to find the EGR valve. Look next to the large air hose on the left side of the engine. Youll see the EGR valve here. The valve is metal and shaped like a small can. It has a black vacuum hose coming from it as well as an electrical harness.

2

Depress the tab on the electrical harness and pull it away from the EGR valve to disconnect it. Grasp the end of the vacuum hose and gently pull it away from the EGR valve port. You may have to wiggle it a bit. Do not use a tool to remove the vacuum hose; simply use your hands. Using a tool, such as pliers, could damage the hose.

3

Remove the two Phillips screws from the top edge of the EGR valve. Set the screws aside.

4

Remove the two bolts from the side of the EGR valve. Use a ratchet with an extension for leverage. If you have trouble removing the bolts, spray a bit of penetrating solvent on them and let it set for about five minutes. This should help loosen them and make them easier to remove.

5

Pull the EGR valve straight up to remove it from the engine compartment.

Exhaust gas recirculation valves, better known as EGR valves, minimize your car engines creation of nitrous oxide, which can be harmful to the environment. EGR valves play a crucial part in cutting down on the creation of smog. EGR valves help to reduce the overall temperature of the engine by introducing a portion of exhaust gas back into the combustion chambers. The exhaust gas takes the place of otherwise combustible material (air and gasoline), thereby causing cooler combustion temperatures while still generating the same force to push the piston. EGR valves can reduce smog creation by as much as 60 percent. Several major types of EGR valves exist.

Single Diaphragm EGR Valves

Single diaphragm EGR valves are the oldest and simplest type of EGR valve. They consist of a spring-loaded diaphragm connected to a pintle and seat by a slender steel shaft. Vacuum is ported into the diaphragm, which causes the pintle to pull off of its seat. The removal of the pintle from its seat results in the exhaust being allowed to flow into the valve chamber and the intake manifold.

Positive Back Pressure EGR Valves

Positive back pressure EGR valves have a much thicker pintle shaft than a single diaphragm valve. They also usually have a "P" stamped next to the part number and date code. The pintle shaft on these EGR valves is hollow, and it is the play between this hollow control valve and a control valve that regulates vacuum flow that causes the valve to work. Exhaust gases flow into the shaft itself and push up on the shaft, which it turn seals the built-in control valve. Vacuum pressure pulls on the diaphragm and causes it to open.

Negative Back Pressure EGR Valves

Negative back pressure EGR valves can be identified by the "N" stamped next to the date and the part number. It looks very similar to a positive back pressure EGR valve. This EGR valve is opened by a combination between applied engine vacuum and negative exhaust system impulses. When the pintle opens, back pressure is reduced. This reduction causes the control valve vacuum bleed to open and a valve to close. The negative exhaust pulses help to regulate the flow of gas.

Integrated Electronic and Mechanical EGR Valves

An integrated electronic and mechanical valve can be identified by its single vacuum source inlet and three-wire electrical connector. Its basic operation is similar to a single diaphragm EGR valve except for a small pintle position sensor atop its diaphragm. This sensor communicates with the power control module, which in turn applies vacuum when necessary by signaling a pulse width modulated solenoid.