AUTONET TV

Why You Have an O2 Sensor (Oxygen Sensor)

If someone asked you what gas made up the largest portion of the atmosphere, what would you guess? Well, it's not oxygen; it only makes up 20.9 percent.  But since we're talking about oxygen, you should know that your vehicle uses oxygen sensors to make sure your engine is running the way it should.

The oxygen sensors measure how much oxygen is in your exhaust.  If there's too much, it means there's a problem with the mixture of fuel and air.  The sensor sends signals to computers in your engine and adjusts the mixture so it maximizes performance and efficiency.  It does this constantly. 

Many vehicles have multiple oxygen sensors.  Some have one close to the engine, another close to the muffler.  Two measurements are better than one since they allow readings to be more accurate.  You may have a vehicle with a dual exhaust, so you'd have twice as many oxygen sensors.

Your oxygen sensors can fail.  One thing that can damage them is contamination from bad fuel.  The sensors can simply wear out, though they usually last a long time.  It's not unusual for an oxygen sensor to last 100,000 miles/160,000 km. One more thing that can cause an oxygen sensor to fail is residue from an engine that's burning oil.  Plus contaminants from the road like salt can also cause problems. 

Here are some signs that your oxygen sensors might be failing.

• The Check Engine light goes on.  In this case, your service facility can plug in a device that will read the code in your engine's computer to see if that's the problem.
• The engine is running roughly.
• Black, sooty smoke is coming out of your tailpipe.
• Your fuel economy is noticeably lower than it used to be.

Head to your service facility and tell your advisor what symptoms your vehicle is experiencing.  They have the equipment and training to track down the issue.  Note that simply replacing the oxygen sensor is often not enough since it doesn't get to the root of the problem; other repairs may be needed. 

So make sure your oxygen sensors are working the way they should be.  Oh, and back to the question of what gas makes up most of the Earth's air?  It's nitrogen, which comprises 78 percent of the air we—and our engines—breathe.

Madison Automotive
2457 Covington Pike
Memphis, TN 38128
(901)386-9600
http://www.madisonautomotive.net

Stop It! You Need Good Brakes

Good brakes are obviously very important. If you've ever had your brakes go out while you're driving around the Memphis area, you'll know how terrifying it can be. Today we'll focus on how to tell when you have a brake problem and how to make good repair choices.

Often, the first indication that something's wrong with the brakes is an unusual sound. It could be a squeal, chatter or grinding sound.

Some brake pads have a little piece of metal embedded in them that will make a squeal or chirping sound when the brake pads have been worn down to the point that they need to be replaced. It's an early warning indicator.

When you hear that sound, schedule an appointment at Madison Automotive soon.

Now a chattering sound is more urgent. That usually indicates that something is loose. It could be a brake pad or even the brake calipers. If one of those parts falls off, you could have some serious trouble stopping the vehicle. It would be a good idea to park it until you can get into the shop.

A grinding noise usually means that the brake pad is completely worn away and the metal parts of the brake are rubbing directly on the metal brake rotor. That means the rotor is being damaged and will need some work. More on that later.

Another warning sign is that your brake pedal may feel soft and spongy – or it may even feel very hard to push in. Both could mean trouble. And of course, you may get a dashboard brake warning light.

Now when it comes time to replace your brake pads, you have a choice to make. You can get the same pads that came standard on your vehicle. You can expect the same performance and durability as with the pads that came on the car from the factory.

Now you can also get a budget brake pad. Sometimes Memphis drivers insist on lower cost pads. That's OK if the budget demands it, but you need to be aware of the tradeoffs. Lower grade pads are usually noisier, so you'll have to live with more noise when you apply the brakes. They also tend to generate a lot more brake dust, you know, that black dust that accumulates on your wheels. And they probably won't last as long either. In our opinion, that's a lot of compromise for just a few dollars in savings.

You can also choose to buy premium brakes pads at Madison Automotive. These perform at higher specifications than the factory pads. You can expect quieter operation, less brake dust and better stopping power.

Now, getting back to the rotors. The rotors are the discs that the brake pads clamp down on to stop the vehicle. If you've been driving with completely worn brake pads, you've scratched grooves into the rotors. If the grooves aren't too deep, the rotor can be resurfaced. A thin layer of metal is cut off the surface of the rotor to make it smooth again.

Now, if the grooves are too deep or if the rotor has already be resurfaced before, there may not be enough material to resurface and still have a rotor that's thick enough to safely stop the vehicle. In that case, the rotor will have to be replaced.

Something that's often overlooked is the brake fluid. Your manufacturer has a recommended schedule for evacuating the old brake fluid, cleaning the system and refilling it with fresh brake fluid. This is really important to brake performance.

So here's the bottom line: if you suspect, inspect. If you notice any of these warning signs, have your brakes inspected at Madison Automotive in Memphis. Your service advisor can help you make the repair decision that's right for you.

Madison Automotive
2457 Covington Pike
Memphis, TN 38128
(901)386-9600
http://www.madisonautomotive.net

What's in a Number? (What Tire Numbers Mean)

You've probably never paid much attention to the writing on the sides of your tires, but they contain a wealth of information.  There's a long combination of letters and numbers that can tell you a whole lot about what tires your vehicle was designed to be riding on.  Let's check out this example found on an SUV: P245/70R17 108T.

The first letter, P, means it's intended for passenger vehicles.  If there's no letter, it means it's a metric tire.  If there's an LT at the beginning or end that means a tire designed for light trucks.

Moving on to our example, the 245 shows how wide the tire is in millimeters from sidewall to sidewall.  The number that follows in our example, 70, means the height of the tire is 70% of its width.  The letter after that in our example, R, describes the type of tire (on this vehicle, radial).  Following that is the diameter in inches, in our SUV example, 17 inches. 

How much load the tires' sidewalls are designed to take is what that next number is all about (108 in our example).  The higher the load index, the more weight the sidewalls can take.  And the last letter is the speed rating of the tire, in our example, T.  The further along in the alphabet that letter is, the higher its speed rating.  So now you know what those letters and numbers mean.  But why are they important?

When you are getting ready to replace those tires, those numbers are telling you what the original equipment was when your vehicle was new.  Sticking with the same rated tires is always a good idea.  If you don't know what you're doing, trying different sized tires and wheels can cause real issues when it comes to performance and safety, considering all the computerized systems now found on vehicles.  When in doubt, consult your service advisor when it comes to buying new tires.  He or she knows what those tire numbers and letters mean… and a whole lot more.

Madison Automotive
2457 Covington Pike
Memphis, TN 38128
(901)386-9600
http://www.madisonautomotive.net

Wipe Out! New Wiper Blades for Memphis Drivers

When people in Memphis talk about vehicle safety, they think of tires and brakes. But do we think about our windshields? Isn't the ability to see a prime safety factor when it comes to driving around TN? Yet we often don't even notice our windshields until we can't see through them or our wiper blades fail.

It's estimated that around 46 million people are driving with wipers that won't keep their windshields clear during a storm — that's 46 million people with impaired vision during a storm. For safety's sake, Memphis drivers need to change the way they think about wiper blades. Most of us, 78% in fact, only change our wiper blades after they fail. In other words, we don't get new ones until the old ones become a safety hazard. Instead, we need to make wiper blades part of our preventive maintenance routine.

Wiper blades should be changed twice a year, in the spring and in the fall. In TN areas that experience harsh winter weather, special blades are available that prevent ice and snow from collecting on the wiper. Ask your friendly and knowledgeable service advisor at Madison Automotive about wiper blades that repel ice and snow.

No matter what blades you use on your vehicle in the winter, don't expect them to clear the ice and snow from your windshield after your vehicle has been parked for a while. Using your wipers will shred your blades and may even damage your wiper motor. And don't drive on Memphis roads with a frosted windshield. That's a serious safety hazard. It can cause accidents, and you could be held liable.

Wiper blades are subjected to harsh conditions in TN. They're out in the Memphis sun and in the cold. Over time, they become hard and brittle and lose their flexibility. Then they start to tear. Without flexibility, wipers just can't clear a windshield of water or snow. And torn wipers can actually scratch your windshield. Then the entire windshield has to be replaced — along with the wiper blades. It's a prime example of how preventive maintenance could have saved you repair bill.

Memphis drivers can purchase new wiper blades at Madison Automotive or at any Memphis auto parts store. They cost about the same. But at Madison Automotive we'll also throw in the installation.

Once you have good wipers installed, don't forget to top off your windshield washer fluid. If you take your vehicle in for a full-service oil change at Madison Automotive in Memphis, your washer fluid will get topped off then. But it's good auto advice to purchase a jug of washer fluid to keep at home — just in case. And pack it in the car when you go on long trips.

While we're on the subject, Madison Automotive advises Memphis drivers to always fill their washer fluid reservoir with windshield washer fluid. Don't ever use water. Water can freeze in the reservoir, which can damage it. It can also freeze onto your windshield. Besides, plain water just can't get a windshield clean. Think about it. Do you use plain water to clean your bathroom mirrors? And a bathroom mirror doesn't get exposed to anything near the gunk that can end up on your windshield. Windshield washer fluid was designed to do one thing — to clean windshields. Let it do its job.

A clean windshield is not just good vehicle care for Memphis drivers — it's also a safety feature. Let's keep it that way.

Madison Automotive
2457 Covington Pike
Memphis, TN 38128
(901)386-9600
http://www.madisonautomotive.net