Repair 7

On July 19, 2001 the Ford Motor Company issued a fuel system gasoline recall regarding a damaged check valve in the fuel pump sender assembly of F-Series pickup trucks. The potential number of vehicles affected is 1,556,221, according to the recall notice.

Affected Vehicles

The vehicles affected by this recall are 1990-1993 Ford F-Series pickup trucks equipped with dual fuel tanks. The recalled vehicles will have a 4.9, 5.0, 5.8 or 7.5-liter gasoline engine.

Problem

Vehicles affected can experience the transfer of fuel from one tank to the other due to a malfunction of the check valve in the fuel system. When fuel returns to the tank not being used, which is called cross flow, the non-operating tank capacity can be exceeded, which can cause fuel to run out past the filler cap and possibly create a fire hazard.

Solution

Ford has extended the warranty for possible fuel cross flow to 12 years or 150,000 miles from the start date of the warranty, whichever comes first. Dealers will repair the fuel cross flow condition at no charge.

Although not essential, all modern gasoline automobile engines depend on exhaust gas recirculation or EGR valves to reduce toxic nitrogen oxides from emissions. The removal of EGR valves, while long debated, has not been shown to have any performance benefits.

Function

Dangerous nitrogen oxide gases form when gasoline combustion chambers reach temperatures in excess of 2500 degrees Fahrenheit. To combat this, the EGR valve was introduced in 1973 by General Motors to recirculate exhaust gases into the combustion chamber, drastically reducing temperatures and the formation of nitrogen oxides. EGR valves do not function at idle or wide open throttle and generally increase fuel economy and performance.

Disconnecting the EGR Valve

For some, the benefit of more engine bay space is enough to make removing the EGR valve worthwhile. In order to do so without interferring with engine operation, the engines electronic control module (ECM) must be set to never activate the missing EGR. Additionally, an EGR plate must be installed to cover the hole in the intake manifold where the EGR valve was installed.

Considerations

On most cars a missing EGR valve will cause the vehicle to fail emissions testing because of a tripped check engine code and the presence of heightened levels of nitrogen oxides.

The PCV valve on the 1988 Ford Mustang engines is responsible for recycling unburned gas from the crankcase back to the combustion chamber. PVC is defined as positive crankcase ventilation. The PVC valve is considered an emissions component because it prevents the unburned gas from blowing out into the air. The valve has a pressure release ball inside that opens and closes due to pressure from the crankcase. Once a high amount of pressure from the unburned gas pushes against the pressure release ball, the ball will open and release the unburned gas into the combustion chamber.

Instructions

1

Park the 1988 Ford Mustang and open the hood. Set the parking brake to prevent the car from rolling away as you repair it.

2

Locate the silver colored L-shaped PCV valve, located on the valve cover closest to the air filter housing. The PCV valve is inserted into a rubber grommet on top of the valve cover. There are two plastic tubes on top of the PCV valve.

3

Pull the plastic tubes off of the PCV valve with your hands. If the tubes are stuck, twist them as you pull them off.

4

Pull the PCV valve straight out of the rubber grommet seated on top of the valve cover. Wipe down the area around PCV valve and the rubber grommet with a clean rag to remove any dirt or grease.

5

Push the new PCV valve into the rubber grommet and reattach the plastic tubes to the top of the PCV valve. Make sure the new PCV valve is completely seated into the rubber grommet. Close the hood.

The Positive Crankcase Ventilation (PCV) valve prevents vapors from leaking from your 2007 Jeep Libertys engine into the atmosphere. The PCV valve forces harmful vapors back into the combustion chambers, so that they burn off during the fuel combustion cycle. When your Libertys "check engine" light comes on, or when your vehicle fails an emissions test, the PCV valve most likely has failed. Buy a replacement valve from an auto parts store.

Instructions

1

Raise the hood of your Liberty and rest it on the prop rod. Locate the PCV valve protruding from the back of the left cylinder head.

2

Pull the rubber hose straight back off the end of the PCV valve. Unscrew the PCV valve from the mounting area, by hand. Discard the old valve. Thread the replacement PCV valve into the mounting area, by hand, until it is secure.

3

Push the rubber hose back onto the end of the new valve. Push the hose back until it stops, making sure it is tight. Close the hood of the Liberty.

A valve guide is a cylindrical part used to make sure that a valve makes proper contact with a valve seat in a reciprocating engine.

Significance

Each poppet valve in a cylinder head has a valve guide. The valve guide works with the valve spring to make sure the valve stays straight and makes contact with the valve seat. The valve guide guide also conduct heat from the exhaust valve into the cylinder head.

Considerations

Both bronze and steel are used to make valve guides. These materials are used because theyre strong. When a valve guide wears out, the valve doesnt properly connect with the valve guide, which makes oil leaks appear.

Aircraft

Valve guides are commonly used in aircraft engines. In aircraft engines, the valve guides are a tube that flares on one end in a T shape.

The Exhaust Gas Recirculation (EGR) valve on the 2000 Ford Explorer is an important part of the engine emissions system. The EGR valve allows a precisely metered amount of exhaust gas to be circulated back to the combustion chamber. This introduction of exhaust gas into the cylinder allows the engine to achieve combustion at a lower temperature, leading to the creation of fewer smog-related emissions. If the EGR valve is not functioning properly, it can lead to misfires, rough idle, stalling, and failed emissions tests. Fortunately, the EGR valve is easily replaced using basic hand tools.

Instructions

1

Park the Explorer on flat, level ground with the parking brake fully engaged. Raise the hood by pulling the release handle located under the steering column and then pulling up on the lever located under the center of the hood while lifting the hood. Disconnect the negative battery cable with a pair of pliers or open-ended wrench. The EGR valve is located above, and slightly in front of, the exhaust manifold on the drivers side of the engine. The EGR valve is a flat metal disc with a small rubber hose attached to the top and a larger metal pipe running from the bottom of the valve to the exhaust manifold.

2

Remove the small rubber hose from the top of the EGR by gently pulling straight up on the rubber fitting. Unscrew the metal pipe from the bottom of the EGR using an open-ended or adjustable wrench. Remove the two bolts holding the EGR valve to the engine. Remove the valve from the engine.

3

Clean any remaining gasket material from the EGR valve mating surface using a plastic putty knife.

4

Install a new EGR gasket on the mating surface using gasket sealer to hold it in place. Attach the new EGR valve to the engine using new bolts and tighten the bolts to 15 foot-pounds. Reconnect and securely tighten the metal pipe to the bottom of the valve and slide the rubber fitting back onto the top of the valve.

5

Reconnect the negative battery terminal and close the hood.

Valve covers cover the connection between the push rod ends and the rockers of your engine. Valve cover gaskets ensure that the oil coming to the top of the engine to lubricate the rocker arms does not leak from the valve covers. As you use your vehicle, the valve cover gaskets begin to wear. Wearing begins to break down the gasket, allowing oil to leak out of the engine. Fixing leaking valve cover gaskets keeps your engine from seizing from lack of oil.

Instructions

1

Scrape the old valve cover gasket from the gasket flange with a metal putty knife.

2

Apply gasket remover to the remaining gasket material with a small paint brush. Allow the gasket remover to sit on the material for 25 to 45 minutes.

3

Wipe the gasket loosened with the gasket remover from the valve cover flange with a rag. Apply a second coat of gasket remover to the flange to remove any remaining gasket material. Wipe the flange dry with a clean rag.

4

Apply a 1/8- to 3/16-inch thick bead of RTV sealant to the cleaned flange.

5

Press a replacement valve cover gasket into the wet sealant. Allow the sealant to cure for 15 to 20 minutes.

6

Set the valve cover over the engine head to cover the rocker arms. Hand-thread the fasteners over the flange to hold the valve cover in place.

7

Tighten each screw with a matching socket attached to a ratchet handle.

8

Repeat the process on the other side of the engine if it contains a second valve cover.

The steps necessary to check a valve cover gasket are in most part the same steps that would be needed for replacing the gasket. Some of the same tools will be necessary. The valve cover gasket is a rubber filter that ensures the valve cover itself seats well, so then the oil being pumped underneath the cover doesnt seep through it. Over time valve cover gaskets age and become weak, which may result in an oil leak around the lip of the valve cover gasket.

Instructions

1

Remove the valve cover by first taking off the hold down bolts securing it. Use caution in removing these bolts, as they can strip easily. Any difficulty turning the bolts should be remedied by spraying rust neutralizer or oil penetrator on the bolt and trying again.

2

Once the bolts are removed, gently pry off the valve cover. It may be necessary to use a flat head screwdriver or putty knife to pry a corner free before it can be lifted off.

3

Inspect the valve cover, both inside and out. Any problem with the gasket or valve cover will be obvious -- youll see an excessive amount of oil in and around the valve cover. A vehicle owner will generally have valid suspicion well in advance of inspecting the valve cover gasket; both a substantial oil leak and gray smoke coming from under the hood would be an indication that the valve cover and gasket need to be replaced.

4

Distinguish between a leak and a seep, if there is oil present around the valve cover. Seeping oil in cars over thirty thousand miles on the odometer is not that unusual and is not cause to replace the gasket. The distinction is in amounts -- most vehicle owners savvy enough to be inspecting the valve cover should know the difference between a leak and a seep. But in general, if theres oil all over the place, its a leak.

5

Replace the valve cover gasket if an oil leak is present.

6

Reinstall the valve cover, making sure to adhere to torque recommendations. Carefully secure the hold down bolts to make firm the valve cover seat.

A cars engine depends on a balanced ratio of fuel and air for proper combustion and sufficient horsepower. A faulty exhaust gas recirculation (EGR) valve affects the functioning of the mass air flow (MAF) sensor for an engines air flow.

Identification

The EGR valve allows a small quantity of exhaust gas from the combustion chamber into the engines intake manifold, resulting in a cooling of combustion fumes. The MAF sensor, also known as the air flow meter, calculates the amount of air entering the engine for balancing with the fuel.

Effects

Typically, a faulty EGR valve leaks more gas into the engines intake manifold, which has a direct effect on the MAFs functioning. The MAF detects more gas or air within the system and automatically adds more fuel to the mixture to balance the fuel-to-air ratio.

Significance

A faulty EGR valve requires immediate replacement. Aside from wasting excess fuel from an improper fuel-to-air ratio, a faulty EGR valve releases harmful emissions into the atmosphere.

A PCV valve--sometimes erroneously referred to as a "PVC valve"--is a Positive Crankcase Ventilation valve, and is responsible for the continual expelling of gas from an engines crankcase. This is a one-way valve. If you do not change your oil at regular intervals, the valve can become plugged and fail, so you should perform regular oil changes. If the valve does fail, youll need to know how to remove it in order to replace it.

Instructions

1

Pull the hood release lever to open the hood of your vehicle.

2

Run your fingers along the inside of the hood to locate the hood release latch. Once you have located it, pull up on the latch to open your hood.

3

Locate the PCV valve, which will be on the crankcase. Look on the top of your engine or on the sides. It is a small rubber plug that is stuck directly into the engine. It looks almost like a rubber bottle stopper.

4

Pull off any hoses that are attached to the valve. There are two main designs of PCV valves. One is directly plugged into the crankcase, while the other is inline with two hoses. If your vehicle has an inline PCV valve, youll need to simply pull the hoses off the valve and then remove the valve itself. If the PCV valve is plugged directly into the crankcase, youll need to grab the end of the valve with your pliers and twist the valve. Youll need to give it a good pull, but it will come out.

The EGR valve of a Chrysler Sebring regulates the flow of air from the exhaust to the intake system in order to control the air temperature and the amount of nitrogen. A faulty EGR valve will result in poor combustion and engine knock, causing the car to rattle or misfire. Because they are calibrated together, the EGR valve and transducer are sold together and must be installed as a set. While the 1998 Sebring has two different locations for the EGR valve, depending on the type of engine, replacing it is a DIY job that will dramatically improve vehicle performance.

Instructions

1

Raise the car hood and disconnect the negative battery terminal. If your 1998 Sebring has a 2.0- or 2.4-liter engine, the EGR valve is located behind the cylinder head, so remove the large tube connecting the air intake to the air filter for added clearance. On the 2.5-liter engine, the EGR valve is to the left of the positive battery terminal, so remove the transmission control module (TCM) for clearance. The TCM is located to the left of the engine fuse box, and the positive battery terminal is secured by a central retainer and retaining screws.

2

Remove the vacuum tubes and electrical connections from both the EGR valve and electrical transducer, including the line to the solenoid, making sure to label where each tube goes for reinstallation. Remove the metal EGR tube leading to the intake manifold and clean its mounting surface. Unfasten the bolts holding the EGR valve and transducer. Carefully remove each component.

3

Loosely connect the EGR tube with the new EGR valve, using new gaskets. Install the new EGR valve and transducer. Once the components are in place, tighten the screws on the EGR tube and any remaining loose bolts. Reconnect all of the vacuum tubes connecting the EGR valve, transducer and solenoid as labeled.

4

Reinstall any components that you removed for access and reconnect the negative battery terminal. Start the engine and carefully listen for a hissing sound that would indicate a vacuum leak. Correct any vacuum leaks, if necessary, using a small amount of gasket-making compound to seal connections.

Repairing a leaking valve cover is a straightforward procedure. If the valve cover on your Chevy engine is leaking, the most likely cause is the gasket between the head and the valve cover. The quickest way to fix this problem is to replace the gasket with a new one. There are sealers on the market that can help, but they are not a replacement for a properly formed gasket installed correctly on the engine. New gaskets are available at most auto parts stores or through a car dealer.

Instructions

1

Locate the valve cover on the top of the head or heads on the engine. Remove the bolts around the edges of the valve cover with a socket and ratchet, then remove the cover from the head. Set the valve cover aside.

2

Place a rag in the head, around its edges, to keep any debris from falling inside the head, then use a gasket scraper and remove any gasket material or sealer from the mounting surface of the head. Work all the way around the head, making sure you do not leave anything on the surface, or the new gasket will not seal properly.

3

Turn the valve cover over, with the inside facing up, and clean the gasket mounting surface with the gasket scraper; again, make sure there is nothing left on the surface. Using a clean rag and some brake cleaner, wipe down the inside of the valve cover and allow it to dry.

4

Lay the new gasket out on a clean piece of cardboard and lightly spray the gasket with gasket tack. Let it sit for about five minutes, then lay the gasket into the valve cover, tack-side down. Place the valve cover back on the cylinder head, then install the retaining bolts.

5

Tighten the bolts with a socket and ratchet. Do not over-tighten the bolts, or you will crush the gasket and cause it to leak. Repeat the process on the opposite valve cover if you are working on a six- or eight-cylinder engine.

The positive crankcase ventilation valve, PCV for short, is an "L"-shaped mechanical component found in vehicles that assists in returning gasses from the engines crankcase, where gasoline is used.

Significance

The PCV valve is just one part of the PCV system, which uses both optimal gasoline performance and is better for the environment. Instead of allowing fumes from the gasoline to ventilate into the atmosphere, the PCV valve sends the gasses back into the combustion chamber to be used again as additional fuel.

Location

The location of the PCV valve within a vehicle brand and model varies with each company. For the 1997 Nissan Altima, the PCV valve is under the hood of the vehicle, in the upper engine area, found mounted in the intake manifold. Most vehicles follow the same PCV placement by the engine, but exact specifications can alternate.

Appearance

The PCV valve is most commonly part plastic and part metal. The valve has two parts: a vacuum on one end that suctions gasses back to the intake manifold, and a metal sphere inside the valve corner, aiding in efficient transfer of gasses.