The Sign of the Shield (Heat Shield Repair and Replacement)August 16, 2020

Even in the months where temperatures are cooler, heat is still an enemy of your vehicle.  When your engine runs, it creates heat, so there are numerous heat shields that protect other parts from those higher temperatures. Heat shields are installed around several areas of the exhaust system.  Others prevent heat from reaching parts of the vehicle.  Still others prevent heat from reaching the ground (or maybe grass underneath) and starting a fire. 

If you remember your space travel history, you’ll know how important a heat shield can be. John Glenn was the first American to orbit the earth, but during that maiden orbital flight, a sensor on board was indicating the heat shield on his capsule, Friendship 7, was loose.  If it had come off, his spacecraft could have burned up upon re-entry.  Fortunately, the heat shield stayed on, and Glenn made history.

Unfortunately, the heat shields on your vehicle don’t have warning systems like the space vehicles did.  So you have to maintain them.  Heat shields are constantly exposed to elements like water, salt, sand and dirt.  That makes them prone to rusting and corroding.  Here’s one unfortunate fact: Materials that make them good at preventing heat transmission also are soft and vulnerable, often aluminum or special fabric. 

One sign a heat shield will give you that it’s loose is noise; you’ll sometimes hear it rattling underneath your vehicle when it’s running. One way to locate it? Put your vehicle in park, leave the engine running and take a listen outside.  It’s usually pretty easy to pinpoint the location.

Make a note of the noise when you are talking with your service advisor. It’s important to have those heat shields working correctly so the heat is kept away from your other vehicle systems and combustibles on the ground. The good news is that heat shields can frequently be inexpensively repaired or re-attached.  In other cases, they should be replaced. 

Missing or loose heat shields? Let’s just say they’re not cool.

Lewis Complete Auto Repair
5110 Grisham Dr.
Rowlett, TX 75088
972.475.4800

The Right Oil for the Season (Engine Oil Viscosity)August 9, 2020

As the temperatures plunge, certain types of engine oil may not flow as easily as they did when it was warmer.  Makes sense, doesn’t it? Just like molasses gets thicker as the temperature goes down, engine oil does the same thing. So, maybe you’re wondering if you have to change your oil as the seasons change so it’s just the right thickness to lubricate your engine parts. 

How well engine oil flows is called its viscosity. There are different types of oil—some that have just one viscosity and others called “multigrade” oils.  Here’s the difference.

A single viscosity oil will flow better when it’s hot but not as well when it’s cold.  A multigrade oil is engineered so that its flow properties at cold temperatures are different than they are at warm temperatures.  In other words, a multigrade oil can start out in colder temperatures acting like a thinner oil and then behave like a thicker oil when it’s warm.  That’s a pretty cool trick and it’s why multigrade engine oil is used in nearly all vehicles.  Your vehicle’s manufacturer has the correct viscosity of oil for your particular model included in the owner’s manual.

Another choice you have to make when it comes to engine oil is whether you use conventional oil, synthetic oil or a blend of the two.  Synthetic oils have some advantages over conventional, such as resisting breakdown better and withstanding higher temperatures.

Check with your service advisor to see which viscosity and type of oil is recommended for your vehicle.  It’s important that in cold weather, the oil flows through your engine at the right thickness so that parts are being properly lubricated.  That will make sure you’ll get good fuel economy and performance, no matter what the temperature is.

Lewis Complete Auto Repair
5110 Grisham Dr.
Rowlett, TX 75088
972.475.4800

Passing the Test (How to Prevent Emissions Test Failure)August 2, 2020

Vehicle emission testing has become ubiquitous in North America and for a good reason.  Clean air quality is important for the environment and all of us.  Since vehicle emissions are among the main causes of air pollution, emission testing can alert you to problems in your vehicle than can be fixed so it won’t needlessly pollute.

Emissions tests are looking for certain toxic gases internal combustion engines produce, such as nitrogen oxide, particulate matter, non-methane organic gases and formaldehyde.  Emissions control systems reduce these gases if they are working properly. 

The best way to minimize pollution is to keep those vehicle systems working properly, and periodic inspection and maintenance is the key.  So if you want to make sure your vehicle will pass an emissions test, it helps to know what might go wrong.

Let’s start on the easy one.  Your gas cap could be loose, allowing vapors to escape into the atmosphere.  The most common solution is to replace it.  Or your air filter may be dirty.  A dirty air filter may push your hydrocarbons pass the acceptable level.

Now to the more complicated things.  The mixture of fuel and air in your engine may be tilted toward the “too much fuel” side.  That could cause problems for your vehicle’s catalytic converter, a device that converts toxic gases from your exhaust into less toxic pollutants.

Your vehicle has a closed system that prevents fuel tank vapors from escaping into the air; it’s called the EVAP system.  A technician can track down problems.

Vehicle engineers have gone to great lengths to minimize the amount of pollution your vehicle produces.  Your vehicle’s manufacturer recommends how frequently those systems need servicing.  Keep those systems in good shape and you’re likely to pass emissions tests with flying colors.  Neglect them and you might find your vehicle failing an emissions test.  When that happens, you’ll have to get the problems repaired before you can get back on the road.

Lewis Complete Auto Repair
5110 Grisham Dr.
Rowlett, TX 75088
972.475.4800

The Lewis Complete Auto Repair Guide to Servicing Your DifferentialJuly 26, 2020

Differential? What’s that? And what’s it for? I’ve been told by my service advisor that I need to get it serviced, but is that on the level?

Do these questions sound familiar? They’re not uncommon for Rowlett drivers. A lot of us in Rowlett don’t know what a differential is or what it’s for. Every vehicle has a differential, and, yes, it does need to be serviced. In fact, it’s more important to the operation of your vehicle than the air conditioner or windshield wipers.

A differential allows your vehicle tires to move at different speeds. This happens more than you think. The best example is when a vehicle is turning. The inside wheel travels a much shorter distance than the outside wheel during a turn. This means the outside wheel has to move faster than the inside wheel. Without a differential, your tires would hop and skip while turning. They would also lose traction in sand or snow.

The location of your differential depends on what kind of vehicle you drive. On a rear-wheel drive vehicle, the differential is located in the back. For a front-wheel drive vehicle, it is located on the front, but it is usually called a transaxle. Four-wheel drive vehicles have three differentials: one on the front, one in the back and one in the middle. This center differential compensates for differences in speed between the front and rear wheels.

Your differential contains strong gears that need to be protected from dirt, debris, water and other contaminants. A differential is sometimes referred to as a “gear box.” The work of these gears is to transfer power from the vehicle drive train to the wheels.

Your differential needs fluid to lubricate and cool the gears. This fluid, even though enclosed in the “gear box,” can get dirty because the gears grind down over time, releasing tiny bits of themselves into the fluid. Also, the additives in the differential fluid break down and need to be replaced. That’s why preventive maintenance for your vehicle needs to include servicing the differential.

Your owner’s manual can give you recommendations on how often to service your differential. But you should also consult with your friendly and knowledgeable Lewis Complete Auto Repair professional. Lewis Complete Auto Repair can give you some good auto advice on whether your vehicle needs to be serviced more frequently. For example, if you drive in hot or cold TX weather conditions, your differential will need to have its fluid changed more often.

Severe conditions will also affect your vehicle care routine and your differential. Check your owner’s manual for a definition of “severe service” conditions that affect your vehicle. Examples may include driving with frequent stops and starts, a lot of short trips around Rowlett, hot or cold TX weather conditions and towing.

Off-roading is particularly hard on a vehicle’s differential. If you are an off-roader, especially if you cross TX streams or waterways, it is important that you service your differential more frequently than the recommendations suggest.

Properly servicing your differential will extend its life and keep you out of Rowlett auto repair shops. A smooth ride is the result of proper preparation and smart choices.

 Lewis Complete Auto Repair
5110 Grisham Dr.
Rowlett, TX 75088
972.475.4800

 

Idle Talk about Engines (Causes of Rough Engine Idling)July 19, 2020

When you slow down at stoplight, your vehicle’s idle should be smooth as silk.  But what happens when the engine is missing or idling roughly? That’s your engine’s way of telling you, “Hey, I’ve got something wrong with me and if you don’t get someone to find out what it is, I may not start the next time you turn the key.”

You can help your service facility if you can describe the problem in detail.  Here’s a list of things to make a note of:

  • When is the problem happening, when the engine is cold or when it’s been running for a while?
  • Does the rough idling occur when I’m accelerating or when I’m going at a steady speed?
  • Does it happen at high speeds?  Does it happen low speeds? Does it happen at both?

Make sure you describe the problem in as much detail because it will help a technician diagnose the problem.

One of the first things they’ll check is how the spark plugs are firing.  Modern iridium plugs are supposed to last a long, long time.  But they CAN eventually wear out.  Inspecting the firing end can help the technician figure out the root of the problem.  Corroded or worn out spark plug wires, too, can contribute to an idling irregularity. 

There are other potential problem spots, too.  The technician may check the ignition coil, timing piston rings, valves and cylinder walls. 

If the mixture of air and fuel isn’t correct, that may affect how smooth your vehicle is running.  Your service facility is equipped with diagnostic equipment that helps them pinpoint the problem.  Once that idle is smoothed out to the way it used to be, you’ll be the smoothest operator on the road.

Lewis Complete Auto Repair
5110 Grisham Dr.
Rowlett, TX 75088
972.475.4800