One of the biggest causes of repeat repairs when a head gasket is replaced would be the procedure for tightening down the bolts was not followed correctly. Head bolts must be tightened in the correct order and to the proper amount of torque. Tightening sequences and specifications are available in your car service manual that will also include the step by step repair procedure for your model.

Most cylinder heads are tightened in a sequence that starts in the middle and then moves out towards the ends. The bolts are generally tightened in two or three stages. If the final torque is 100 foot-pounds the bolt may first be tightened to 50 foot pounds all away around before the final specification is reached.

The head gasket has one of the most demanding jobs. The temperature swings are extreme to the gasket material due to its location. When you first start the engine the gasket is very cold. Then after only a few minutes of engine operation the head gasket could reach a temperature of 400°.

The inner edge that actually performs the sealing between the cylinder head and the combustion chamber can see temperatures above 2000°F. The Gasket is also exposed to extreme high pressure and vacuum as the piston rides up and down in the cylinder working its way through its four strokes.

Engine coolant must flow between the cylinder head and the engine block. The gasket seals these two components together and provides a passageway for the coolant to flow. Another fluid that needs to flow between these two components is engine oil. This gasket allows oil to reach the cylinder head and then flow back down to the oil pump again by using holes or passageways.

The head gasket also seals the intake stroke as well as the combustion pressure generated from the upward movement of the piston. It then has to survive the ignition of the compressed fuel charge when the cylinder reaches top dead center.

When I first got into the auto repair business it was most common to find a solid stainless steel head gasket. These types of older gaskets were not as forgiving as the more modern ones available today. The cylinder head and engine deck had to be perfectly straight for the seal to work.

Most modern gaskets or made of a dense composite facing material with a solid steel core. This material is more forgiving and can provide better sealing when using two different types of metals. Most modern cylinder heads are made of aluminum yet still many engine blocks are made of steel. This composite material requires a stainless steel fire ring around the combustion chamber area to protect it.

Many of the latest generation aftermarket gaskets include a bead sealant that increases clamping pressure around troublesome areas such as cooling passages and oil galleys. In most cases these new types of gaskets provide long life. But if you have to replace a head gasket follow the procedure to the letter and do not skip any steps or repeat failure will be likely.

My previous article was about engine gaskets. You can view it as well as other articles I have written on the blog home page. This next link takes you there from this page about cylinder head gaskets. Or you can head back to the homepage and see what this online auto repair website is all about.

For as long as there have been engines there has been a gasket. Over the years the technology has advanced that makes these sealing components more efficient. But every once in a while when they try a new technology sometimes it's actually a step backwards.

A quick example of this is just my personal opinion. The latest in Gasket technology sometimes referred to as a composite looks and feels like plastic. An example of a step backwards is in the reliability of the Gasket in the General Motors V6 intake manifold. This part looks like a strip of plastic with embedded rubber seals.

Using this type of technology the bolts are torqued very light to prevent cracking of the sealing component. The lighter the bolts are torqued the more of a chance it has to back off or loosen.

And if you pop the hood on a GM six cylinder vehicle chances are you can find evidence of coolant leakage from around the intake manifold. This problem is most evident on late 90 and early 2000 model years.

A gasket in general is used to prevent gas or liquid leakage between two parts that are bolted together. They can also serve as spacers to provide proper clearance between the two items that are bolted together.

When it comes to leaking engine gaskets you will find that the materials that they are made out of will fall into a few categories. The first one being a hard one such as steel or other types of metal. These would be used in applications such as exhaust manifolds and cylinder heads that generate extremely high temperatures.

You will still find some soft gaskets that are made of materials such as cork or rubber or a combination of the two. Some people would also throw silicone RTV and other compounds that come in a tube in this category as well. I personally avoid using tube sealers whenever possible because in my opinion it is the least reliable.

Some of the best gaskets on the market today would be a formed or molded silicone type. If you notice this type of sealing gasket can come in three colors. Black is considered for general applications. A blue color gasket is often considered a specialty gasket that can be manufacturer specific. And the most common would be a red or dark orange. This type of silicone gasket is used in high temperature applications.

In my opinion one the most important things about sealing a leak on the engine is finding the right replacement gasket. I prefer to use factory original parts whenever possible. In a pinch I will use an aftermarket part.

But I will never use silicone from a tube instead of a gasket. There are times when you will need to use silicone or RTV. This is when the factory has applied it to the sealing surface. But if there is a gasket you want to replace it with a new one.

Often I see driveway mechanics trying to reuse old Gaskets. This is not recommended even if the old Gasket appears to be in good condition. It just will not seal as good as a new one because it has all ready been compressed.

When you're installing new sealing parts taking the time to clean the surfaces is extremely important. The new parts will seal best when used on clean surfaces. Make sure you get all of the dirt, oil deposits, loose rust, old sealer and even the tiniest pieces of the old gasket material off of the sealing surface.

I hope you found this article helpful. If not give me another chance. This next link takes you back to the online auto repair blog from this page about leaking engine gaskets. Review a few more articles about automotive repair and how the Internet can help you fix cars at home.

The onboard computer is capable of quite complicated misfire monitoring. The engine control module uses the crankshaft angle measurement to detect this misfire. It's actually quite amazing how it is performed. Click the read more button to see how it works.

If the cylinder is providing normal power a specific crankshaft acceleration time would be monitored. When that very same cylinder misfires the cylinder does not contribute to the rotation of the crankshaft as it is supposed to.

So it is actually the crankshaft speed that tips the computer off that there has been a misfire. As for flagging that misfire there is a little bit of tolerance built-in to most OBD two systems. Some will allow a random misfire rate of 2% before the misfire is flagged as a fault and the check engine light is turned on.

Although the misfire code can be helpful in diagnosis it doesn't actually tell you what the problem is. In the best case scenario a misfire code will set for a specific cylinder. This will at least aid you in diagnosing the problem as it narrows it down to one cylinder.

In the case of a random misfire this may mean that multiple cylinders are detected to have problems. A random misfire can be much more difficult to diagnose. But in either case a misfire can be caused by a fuel problem, or a problem with the spark system. This can be individual coils, spark plugs or ignition wires.

The check engine light is turned on during the misfire to notify the driver that the emissions system is not functioning properly. It will be up to the individual mechanic to perform diagnosis from there to properly solve the problem. I have more on this subject at my page about engine misfire codes. For more information about what is covered on this car repairs website visit the homepage for online auto repair.

A power sunroof can slide the roof panel open or closed. You can also tilt the roof panel up in the back to allow fresh air into the passenger compartment. When driving down the road this can also pull a vacuum and remove stale air from the interior cabin.

In most cases power sunroofs are not that much different than electrically operated power window systems found in most automobiles. Many common parts are shared such as system relays, a master control switch and the motor assembly to perform the movement.

Note that most power sunroof systems are protected by a circuit breaker instead of a fuse. This is in case the sunroof begins to bind. It protects the motor by opening the circuit breaker. Often when people have power sunroof problems they will begin to look for the fuse when there is actually none. A circuit breaker will reset automatically when it cools down.

Most power roof master switches have a two or three position operation. This allows the motor to run in different directions to accomplish different tasks. Some of these switches will have an open and vent position. When you select the open position the motor runs the glass back into a stored position. When you select the vent position on the master switch it will just tilt the back of the glass up providing a venting operation.

When you select the close sunroof position often the polarity is reversed to the power sunroof motor to run it in the opposite direction to perform the opposite tasks mentioned above. Some of the newest sunroof options include a solar sunroof that is available on many luxury models.

This feature uses elements mounted either in the glass or under the glass to produce electricity to power a ventilation fan inside the interior cabin. This solar powered venting system will operate even with the ignition switch off. The benefits are that it will provide a continuous flow of fresh air to the interior cabin.

Often power sunroofs are a popular option that does not get used very often. When this system sits for months or years without being used often components can develop corrosion that may hinder operation when it is finally desired.

Since a sunroof is part of the exterior surface of the vehicle a complete watertight seal is necessary. If this seal fails or the automatic drain becomes clogged with debris and water sits around the components the corrosion mentioned above will be accelerated. For this reason a very common sunroof problem is water sealing and drainage.

Diagnosing power sunroof problems is pretty straightforward. The first thing to check would be the circuit breaker. Next you would want to verify power at the motor connector. In that case you would be working from the load back towards the battery. If there is no power at the motor you can break out a wiring diagram and do some pinpoint checks at the relay and switch.

This next link will take you to a good place if you are looking for more information about wiring diagrams or online auto repair service manuals. Or you could head back to this blog's main page from this page about power sunroof problems.

Engine belts are important anytime of the year and not just on the 4 liter Ford engine. In my opinion the summer months put the most stress on your drive belts. When outside temperatures are over 100 degrees it is this rubber drive belt that provides air-conditioning to the interior compartment and coolant flow to the engine via the water pump.

When the serpentine belt breaks on a cold winter day the outside temperature may allow you to drive to the nearest service center. On a hot summer day when this happens if you don't pull over quickly and turn off the engine serious damage could occur. So print out this 4 Liter Ford Belt Diagram and throw it in a storage compartment along with a new serpentine belt and the needed tools.

Belts are used to drive water pumps power steering pumps, alternators, and air-conditioning compressors as well as air pumps and other emission controls on some vehicles. This is also one part that is often neglected by the typical motorist. It is very rare that someone will take the extra effort to check this vital component before heading out on the road trip in the middle of summer.

Not only should the belt be inspected for wear, cracking and damage from external debris but the tension of the belt should be checked as well. Insufficient tension may allow the belt to roll off of a pulley or not turn it efficiently due to poor contact.

Over time serpentine belts will stretch and lose their tension. To compensate for this the 4 L Ford engine has an automatic belt tensioning system that is spring-loaded so that the right amount of pressure is applied automatically.

When this spring starts to wear then looseness can develop. In many cases the first signs of a problem would be a squealing sound when extra load is applied to the serpentine belt. An example would be when you turn on your air-conditioning system on your explorer and then apply some RPMs you may hear a screeching sound from the slipping drive belt.

Although not common on the 4.0 L engine or the Ford Explorer on other vehicles it can also go the other way where excessive tension may put unwanted stress on the pulley and the accessories that they drive. This can lead to a belt breaking but can also lead to premature wear of the component that it drives.

For more information and pictures of popular serpentine belt diagrams visit the page that has nothing but links to engine belt diagrams. For more automotive repair information on a variety of subjects visit the blog section of this online auto repair website. This next link will take you to the recent posts listing area from this page about the 4 Liter Ford Belt Diagram.

Before we get into what to look for when your power seat is not working let's talk about why this issue is more common.

Vehicles that are equipped with a power seat option are becoming much more common than they were just a few years ago. Where as they use to be exclusively deployed on luxury cars you can now find this popular option on even the most basic models.

The power seat option generally comes in two different configurations. The most popular is the four way power seat. But many models still use a six way adjustable power seat. In the simpler four way system the seat bottom moves up or down and backwards and forwards.

In a six way power adjustable seat they include those movements but with the addition of having the ability to control the seat back that in many cases this includes a lumbar support function as well as being able to tip the seat bottom by adjusting the front higher or lower separate from the back adjustment.

Often when I find power seat problems where it is not working in any direction at all, I find in many cases that the power harness or wiring has become disconnected.

Although this wiring is tucked away sometimes passengers or children can accidentally dislodge it and inadvertently disconnect the connector. If this is not the case the next thing to check is the circuit breaker. This is usually located in the main fuse panel.

Circuit breakers are easy to test with an inexpensive automotive meter. The circuit breaker when removed should be in the closed position and you can do a simple continuity test to confirm that it flows current. If the circuit breaker is open then it will have to be replaced and the system further tested.

If the circuit breaker continues to overheat and open the circuit your attention should be turned to inspecting the seat tracks for debris or binding. Even if a soda is spilled in the vehicle it is possible for the track to become sticky enough to overheat the power seat motor.

If the power seat was fine in some directions and will not move in other directions from a particular control that switch should be removed and tested. You may need a wiring diagram to find out which terminals on the switch are connected to operate specific functions. It may be worth the time to get this wiring diagram and properly test the switch instead of just replacing it because they can be expensive on some models.

On older vehicles in some cases corrosion can build up on power seat switch contacts. On some models these switches can be disassembled and the contacts cleaned with either electrical cleaner or even a small piece of sandpaper.

You may not be able to solve all of your vehicle's problems in your driveway. But many problems such as a penny causing power seat problems can be solved by most motorists. It is at least worth taking the first few steps of diagnosis to see if the problem is easily solved. Visit this next link for more of the latest posts to this blog about auto repair.

These miniature lightning bolts are commonly called sparkplug firing by most mechanics. If the sparkplug doesn't fire, the engine doesn't start. When diagnosing a no start condition some mechanics will say the reason the engine won't start is because there is no fire.

It is the ignition system that produces the electrical energy that fires the plug. Spark also must be maintained long enough to allow complete combustion of the air fuel mixture in the cylinder. The ignition system then has to deliver this electrical energy to each sparkplug at the right time.

Ignition timing refers to the precise moment the spark occurs. The spark is required when the piston is heading up on the compression stroke and the right time to fire the plug is just before that piston reaches top dead center or TDC.

In many engines the initial timing is specified at a point between five and 20° before top dead center. To get the most performance out of the engine the ignition timing must change as operating conditions also change. Most engine timing changes are required as engine rpm and load changes.

The higher the engine rpm the more often the sparkplug needs to be fired. The ignition system needs to keep up with the changing engine conditions. This means the ignition system must be able to monitor the rotation of the crankshaft and the relative position of each piston so that it can deliver a high voltage surge at the proper time during the compression stroke.

On gasoline engines the high voltage surge that creates the spark comes from a coil. Most automotive ignition coils are capable of producing voltage of between 30,000 and 60,000 V. Which is pretty impressive considering that the vehicle’s battery is only 12 V?

The ignition coil steps up the voltage by multiplying the battery voltage. The process that it uses to multiply battery voltage is also what gives the ignition part its name. An ignition coil is just that. Inside are coils of wire that use a magnetic field to increase voltage.

The construction of the coil and the magic of the magnetic field allows the coil to output pulses or bursts of high voltage that are sent to the sparkplug to ignite the air fuel mixture on the compression stroke.

This is just a simplified general overview of how the spark is created and used to start and run your engine. Although not everybody needs to know this information it can come in handy when you're trying to diagnose a no start condition.

You need three things for an engine to start. You need air, fuel and spark. If you are missing any of those three elements the result is a no start condition. If you find that it is the spark that is missing, all of your attention can focus on diagnosis and troubleshooting the no spark condition.

If you want to see what good and bad sparkplugs look like I have a video on my you fix cars website about replacing sparkplugs. For more of the latest auto repair posts on this site visit the blog auto repair page.

As you might know an airbag is much like a heavy-duty plastic balloon that inflates fully within fractions of a second during a collision. A deployed airbag protects the driver or passengers from injury by limiting and cushioning movement during a crash.

One of the biggest things to remember is that the airbag was designed to be used in conjunction with a seat-belt. The seatbelt holds the person in place so that the airbag provides maximum protection.

These restraint systems have been around for quite some time and therefore vary greatly in the types of technology they use to deploy the bag.

Also when airbags started to be used back in the late 80s they where only placed in front of the driver and mounted on the steering wheel.

Nowadays these supplemental inflatable restraint systems will include side and passenger deployment systems to protect many if not all passengers. Even the driver side airbag in most cases now has an added knee diverter or sometimes referred to as the knee bolster bag.

Now that we have a brief review of the overall airbag picture let's talk about what to do after a collision when it comes time to replace the deployed units to assure that they are ready to do their job again once all vehicle repairs are completed.

It is highly recommended to replace airbag system components with original equipment manufactured replacement parts. Aftermarket parts may appear to be less expensive and yet interchangeable, but internal differences may result in inferior occupant protection.

The factory installed fasteners, screws and bolts used to fasten airbag components have a special coating and are specifically designed for the airbag system. Your body shop should use the specialized fasteners and they should not be substituted for regular or standard grade fasteners.

You should make your body shop aware that you expect all of your airbag components to be replaced with brand-new parts that were made by the vehicle's original manufacturer.

Failure to make your shop clear on this might make them think its okay to use recovered junkyard parts or less expensive and possibly inferior aftermarket airbag parts.

As part of the repair process an interior detail is usually performed and is recommended before the family begins to use the vehicle as usual. The Powder residue emitted from a deployed airbag can cause skin and sinus irritation. This is especially true for people that are sensitive to airborne irritants.

When you get back in your vehicle and turn the key from the off to the run position your airbag or SRS light should light up maybe even flash and then go out. This is a bulb check and a self-diagnostic routine that is performed by the body computer.

If there are any problems with the supplemental inflatable restraint system the indicator light may show a malfunction by staying on. You can visit my other website Auto-Facts.org for more information about airbag warning lights.

Interested in reading more posts right here on the onlineautorepair.net site? This next link takes you to the blog auto repair homepage.

This problem is probably more common than most automotive consumers realize. What spurred me to write this short post about it was a site visitor named Greg posted a story to my other website that described how his auto repair work was not performed.

Greg purchased a dodge van from a dealership that needed some work done. He was told that the needed repairs would be covered under the power train warranty. But after the papers were signed he was told that they would not be covered.

After working a deal out with the service department they agreed to do a long list of repairs for a discounted rate. When Greg got his Dodge van back he decided to take a look at the repaired areas. He was extremely disappointed to find that many auto repairs were not completed as agreed upon.

In the above situation the service manager stated that the mechanic was told what to do and ignored the instructions. When customers complain, the auto repair shop will usually assign blame to an individual. All too often it is the low man on the pole the mechanic. Some say that stuff rolls downhill.

One thing that you can do as an auto repair consumer is attach a note to the steering wheel outlining the items that are supposed to be inspected or repaired. In most cases the service writer or service manager will never actually get into your vehicle. The mechanic the guy who is doing the work most often is the first one to enter the vehicle and he will see your note.

Another thing that you can do to increase the chances that all work will be performed properly and at the price agreed upon is ask for a copy of a signed written estimate. This estimate should be signed by an auto repair shop representative and yourself.

In the story about the dodge van above Greg knew his way around cars and knew exactly what to look for. The dealer stated that they would replace the spark plugs and wires. When he removed the engine cover he could clearly see that neither of these items was replaced with new parts.

Here is one thing that you can do if you're not sure of what a new part would look like. You can find and mark the old part with a permanent marker or similar hard to remove marking. Before you drive away from the auto repair center you can verify that this part was actually replaced. This could be better than asking for the old parts because you can verify it was completed on your vehicle.

There is no question that an educated auto repair consumer is better able to protect themselves against the auto repairs not completed situation. If you are having specific repairs performed such as a water pump replacement you can do some research and get a basic education on that repair procedure so you are properly prepared to deal with any problems that arise.

To shamelessly plug one of my other websites which is called you fix cars.com I have added repair module sections that include a lot of free information about specific auto repairs. You can also search through this blog about auto repair for articles that address your situation. In my opinion Knowledge is the best way to make sure you get what you paid for.

The 4.3 L V-6 has been around for a long time. In fact I probably should have done some research on just how long. But I do not that this engine has been around since at least the mid-80s and I believe it was discontinued in 2005 in favor of the Isuzu line of engines.

Of course in the mid-80s there were several v-belts instead of the one serpentine belt assembly that are on the more modern engines. I thought that I would be able to go out to my vehicle and take a picture of the Chevrolet V6 belt diagram. To my surprise it was missing.

Since it is missing on my 2004 model year Blazer I figured it would be a good idea to post one for the convenience of site visitors.

Here is a Funny story about my own drive belt problems with my Blazer. The original drive belt lasted a good long time and it never made a squeal squeak or any kind of annoying sounds. During my last oil change I noticed that there was a lot of cracking on the belt.

Since my truck is about six years old I figured I would treat it to a replacement drive belt. Normally I would get my replacement parts at a dealership because I do like to use factory replacement parts. But out of convenience and low funds I went to the local parts store for my oil change stuff and the new drive belt.

The local parts store only had one brand to choose from for replacement serpentine belts. This was a made in China part. But since it was about $13 I decided to go for it. There was no problem after the initial replacement. About two weeks later an intermittent squeaking sound started coming from the drive belt.

The intermittent noise turned into a constant noise. I inspected the drive belt pulleys and tensioner and all looked perfect. I decided to order a Goodyear gator back belt which happens to be my favorite replacement aftermarket brand. I installed the Goodyear belt and the noise was gone and has been for a couple of months.

For those with the Chevrolet V6 engine especially the 4.3 L I do not recommend any made in china replacement belt. I don't know if it's the quality of the rubber but when you compare it to the Goodyear belt there is really no comparison. The Goodyear replacement belt is thicker and heavier but more important on the face of the ribs is almost like a felt like material that is perfect for silencing noisy drive belts.

For more information on things to look for during belt replacement visit my engine belt diagrams page. This next link will take you to latest posts to the online auto repair blog from this page about Chevrolet v6 belt diagrams.