Monthly Archives: September 2016

Auto Repair in Mint Hill – Why is my Check Engine Light On?

Check engine light. Car dashboard in closeup.

Check Engine Light

Picture yourself driving down the street, as you’ve done a million times before on your way to work. An orange glow his your peripheral vision, so you look down, and sure enough, it’s a Check Engine Light. This is a scenario we’ve all most likely found ourselves in at one point or another. The Check Engine Light is probably the most well-known light on the dashboard, and rightfully so. However, the light is not perfect. It may come on, but it won’t tell you why. Today, we’ll debunk some of the most commonly asked questions about the Check Engine Light.

What is a Check Engine Light?

The official term for a Check Engine Light is “Malfunction Indicator Lamp” or “MIL” for short. The light is a device used by all modern cars as to warn the driver that something important has happened within the engine or components connected to it. The modern MIL is required by law on every car sold after January 1st, 1996. Many cars before this date have them, but not all.

What does a Check Engine Light Do?

The Check Engine Light specifically comes on if something the vehicle’s On Board Diagnostic (OBD) system deems immediately important.

Can I tell why it came on?

In On Board Diagnostic Second Generation (OBD-II) – equipped in vehicles made after 1/1/1996, no, with the lone exception of Honda. In On Board Diagnostic First Generation (OBD-I) – equipped in early 80’s to some 1995 vehicles, yes.

OBD-I Cars are not designed to be read by computers, so when the light comes on, it will blink to tell you the code. (for example, blink, pause, blink-blink means “12” as blink, pause, blink-blink-blink means “13”)

OBD-II Cars are designed to be read and scanned by computers, so the only way to tell why the light came on is to use a scan tool, a plug-in device like Hum, or a computer designed to read codes such as a State Inspection Machine. The lone exception to this rule is Honda, as many of their cars carried over the blink/pause function of OBD-I.

What does my Check Engine Light look like?

Most Check Engine Lights look like the picture below:

Most forms of Check Engine Lights look like these.

Check Engine Lights

What should I do if my check engine light comes on?

It is highly recommended that you visit an auto shop upon the light coming on. Though there can be false positives (leaving your gas cap loose can cause it to come on, for example), the light is intended to only come on in situations that are especially important, and usually can only be shut off by a shop with code reading technology, unless it is designed to go off by itself.

Can I pass a NC State Inspection with a Check Engine Light on?

No, unless a waiver has been awarded by the state.

What happens once my Check Engine Light has been diagnosed?

Once the cause of the light coming on is determined, the issue is repaired by your local auto shop,and then the light is reset. Manchester Auto and Tire of Mint Hill, LLC. can handle all your Check Engine Light needs from diagnosis to repair. Feel free to call at 704-545-4597.

Auto Repair in Mint Hill – Do I Need Spark Plugs?


The average American doesn’t drive to work every morning in a V10 diesel truck. Chances are this morning, you fired up a gasoline car, and if you did, congrats! You are the owner of happy and healthy spark plugs. Spark plugs in gas-based engines are your car’s heartbeat, in a sense – they are what make your engine actually burn gasoline and run.


What is a spark plug?


A spark plug, quite simply, is a plug that creates a spark. When gasoline is injected around the spark plug, ignites a spark causing the gasoline to combust, causing propulsion.


How does it work?


The model provided by Car Hospital below explains the inner details of a plug.

Auto Repair in Mint Hill


Does everyone have spark plugs?


No, only gasoline or hybrid cars do. Electric cars do not have gasoline to combust and diesels combust their fuel with pressure, not spark.


How do I know if I need new spark plugs?


Spark plugs need replacement for one of two reasons; the first being it has outlived its lifespan (the space in which spark plugs ignite expands over time, causing misfires) or it no longer functions for a physical reason and misfired. You will know of you have a misfire because your check engine light will blink, and your car will shake – sometimes vigorously.

Auto Repair in Mint Hill

An example of a spark plug measuring tool, used in determining a spark plug’s remaining life.


Can misfires damage my engine?


In the short term, no. However, fuel efficiency will be drastically reduced. Over time this can cause problems such as premature engine deterioration, though.


How often should my plugs be checked?


Spark plugs should be checked every 30,000 miles, and replaced when the gap is deemed too large.


Auto Repair in Mint Hill

Measuring a spark plug’s gap.


How is a spark plug replaced?

A spark plug is replaced with everyday ratchets, a torque wrench, and dielectric grease. First, the technician removes the spark plug’s protective outer shell and electricity generators, sometimes called the “coil” and “boot.” Once these are removed and the spark plug is exposed, the plug is removed with a ratchet, similar to how a regular lug nut is removed. The new plug is inserted, and torqued to manufacturer specs. dielectric grease is applied to the boot, and then is reattached. this can take anywhere from 30 minutes to 2 hours, depending on the amount of spark plugs, the position they’re in inside the engine, and the re-placer’s speed.

Auto Repair in Mint Hill – How Do I Maintain My Tires?

Auto Repair in Mint Hill

Tires come in many sizes. Do yours need some TLC?

Auto Repair in Mint Hill – How Do I Maintain My Tires? Tires – though one of the more obvious features of a vehicle, they can be one of the most easily neglected. After all, when we buy a car, the dealership is too busy telling us about the touchscreen GPS and air-conditioned seats to talk about the tires. Though they may seem simple, tire companies have literally reinvented the wheel to make them last for long periods of time and make for a comfortable ride in the process. In reality, the tire is one of the most complex parts on your vehicle.


So if tires are so engineered nowadays, just what makes a tire work the way it does?


Tires are made of three key parts: the sidewall, the ply, and tread. The sidewall is the edge of the tire – the part that actually holds the air in the wheel. The sidewall usually contains a “bead,” a line of rubber specifically designed to hold the tire to the wheel when air pressure is applied, similar to the way a zipper plastic bag works. The ply are steel belts inside of the tire’s rubber base – these belts strengthen the tire and help it keep its form, especially on low-profile tires. Plys are used to determine a tire’s strength. 4-ply is the most common strength used on Car and SUV tires, for example. Finally, the tread is the layers of rubber surrounding the top or the tire, providing grip and stability. Tread, along with the sidewalls, made of a rubber called “styrene-butadiene copolymer,” which is the most common for commercial tire usage around the globe.


Fun fact – tires are naturally white when produced, and are dyed using carbon black. If you use certain dyes when making tires, you can have colored smoke, like red or yellow, for fun. This most likely isn’t going to be found on a set of normal tires, though, so you may need to go to a local car show for colored smoke tires.


Auto Repair Mint Hill – What causes tires  to wear?


Tires wear simply due to use. Just like a kitchen appliance or mattress, a tire will eventually be too worn for further use. Most tires are designed to last between 50,000-70,000 miles, if they are properly maintained.


Auto Repair Mint Hill – What causes premature wear?

Auto Repair in Mint Hill

A tire that wore prematurely on its inside. Notice how the outside tread looks almost new but the inside has the ply dangerously exposed.

Tires can prematurely wear for many reasons, but the three most common reasons are either because the tires are inflated improperly, are not balanced correctly, or are not rotated at correct intervals (or at all!). Poor alignment can also cause premature tire wear.


Auto Repair Mint Hill – Why does rotating tires extend their lifespan?


Rotating tires extends the life because it evens out wear. Front tires almost always wear faster than the rear tires because they turn and control the car’s direction. By rotating tires, you prevent any of them from being on the front for too long. If done correctly, tires will wear evenly so that all four need to be replaced at once, as compared to two at one point and the other two at another. As a rule of thumb, tires should be rotated every time you get your oil changed.  That is also a good opportunity for the technician to inspect your tires for any unusual wear or tear that might indicate you have a problem.


Auto Repair Mint Hill – Why does improper inflation make tires wear unevenly?

Auto Repair in Mint Hill

A visual of common types of uneven wear.

When a tire is underinflated, it buckles, and only the edges of the tread will touch the ground and wear faster than the rest. When overinflated, only the middle of the tire touches the ground and wears prematurely than the rest of the tire. A tire is only as good as its worst point, so keeping proper inflation is crucial. Your car’s manual states what the proper inflation should be, and there may also be a sticker on the door of your car stating proper inflation.  Newer cars have a tire pressure monitoring system that alerts you with a light on your dash if your tire pressure falls below the optimal level.  If you see this light come on bring your car into Manchester Auto and Tire of Mint Hill and have our technician check it for you.  You may be low on pressure or have a slow leak that you were unaware of.


Auto Repair Mint Hill – Why  do unbalanced tires wear prematurely?

Auto Repair in Mint Hill - Picture courtesy of Plymouth Tyres (United Kingdom).

Wheel weights are small rectangular shaped weights that are used to balance the weight of all four tires evenly. They are applied and removed without damage.


Tires must be balanced so all four weigh the same when inflated properly. If one is too light or too heavy, it may wear faster do to being overworked. Unbalanced tires also can make for a bumpy ride.  This is another service that is good to perform while you have your oil changed and they are rotating your tires.  If you feel a vibration or bumpy ride you can always get a balance check to while you are having your tires rotated.


Auto Repair Mint Hill – How do I know if I need tires?

Auto Repair in Mint Hill

The penny test for your tires. Be sure to hold the penny upside down if you do this test. Thanks Abe!

In North Carolina, tires may be no lower than 2/32”, by law. You can measure this with a penny. The distance between the top of Abraham Lincoln’s head and the edge of the coin is almost exactly 2’32”. If you can see all of Abraham Lincoln’s head, you tire is at or lower than 2/32” and it is time to replace.


Auto Repair Mint Hill – Where can I get tires?
Manchester Auto and Tire of Mint Hill provides tires, and does everything from install, mount, balance, and align tires with nothing less than state of the art equipment. We provide multiple brands like Hankook, Michelin, Cooper, Goodyear and Pirelli tires. You can purchase these tires straight through us and our suppliers, or buy them yourself on We are a Tire Rack Certified Recommended Installer, and you can have them shipped directly to our shop for convenience.