AUTONET TV

The Right Oil for the Season (Engine Oil Viscosity)

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.

McLearen Shell
3043 Centreville Road
Herndon, VA 20171
(703) 318-7744
http://www.mclearenshell.com

A Hot Mess (AC System-Compresser)

Air conditioning used to be a real luxury in a vehicle, but now it's standard in most.  Your vehicle's air conditioning system is built to last a pretty long time, but like anything mechanical, sometimes it fails. 

It helps to know a little about how the A/C works. There's a compressor that pressurizes the refrigerant (you probably recognize the term Freon).  That makes it hotter, so it then goes through a condenser that cools it off.  Then another component takes out impurities and humidity before the Freon goes to a device that makes it lose pressure before it goes to the evaporator.  That's where it gets colder and takes the humidity out of the air. Then your vehicle's ventilation system blows air over the evaporator, cooling the cabin air that gives you such relief on a hot day.

Of all these parts, one that does a lot of work is the compressor.  It has to compress that refrigerant and circulate it through the system.  It turns on and off several times when it's working. The good news is that if it's going to fail, it sometimes lets you know. 

One of the signs that your air conditioning compressor is going bad is a noise under the hood when the engine is on, sometimes a squealing or grinding sound. It usually is pretty noticeable. Compressors have a bearing that can seize up after time, causing the belt that drives it to squeal when it's trying to turn something that won't turn.  It will sometimes cause that belt to break. 

Your service advisor can tell you if your compressor is repairable or must be replaced.  In the case of a broken belt (often a serpentine belt that drives several components) the belt will have to be replaced as well.

The compressor also has a clutch that turns the compressor on and off so it doesn't have to run all the time. Sometimes that clutch can fail, too, and your service advisor will often recommend you replace the compressor and the clutch at the same time. Our technicians can help make sure your air conditioning system keeps its cool, and you along with it. 

McLearen Shell
3043 Centreville Road
Herndon, VA 20171
(703) 318-7744
http://www.mclearenshell.com

Oh, Stop! (Disc Brake Service)

Every time you drive your vehicle, you wear down your brakes just a little bit.  And after a while, that adds up.  Gradually, your stopping power isn't like it used to be.  Since brakes are one of your vehicle's most important safety features, it just makes sense to keep them performing well.

Most vehicles have disc brakes.  One key component, as the name suggests, is the disc.  Most vehicles have discs on their front and rear wheels.  The discs (also called rotors) are made of metal, and each rotates with the wheel hub.  Your brakes also have pads that make contact with the rotors when you press down on the brake pedal, and the friction stops your vehicle.

After many, many stops, that friction wears down both the pads and the discs and reduces their ability to stop the way you need them to.  The discs may also become uneven from all the heat they generate, and your brakes won't stop as well as they used to when they were newer. 

Some signs that your rotors need attention include vibration at the wheels when you stop, discolored rotors (the metal looks blue), excessively hot rotors, or grooves in the metal.  If you see any of these signs, it's time to bring in your vehicle for us to inspect your brakes. 

A technician will measure the thickness and trueness of the rotors and check the surfaces for wear.  If they need to be replaced, they'll be done in pairs, so if a front rotor is bad, the other front rotor will also be replaced. Usually, your brake pads will be replaced at the same time.  You can ask your service advisor if higher-performance brakes would benefit you.

When your vehicle is at the shop, the technician will check other components of your brake system to make sure they are operating safely. Brakes are vital to the safe operation of your vehicle.  Keep them well maintained so they can be there when you need them.

McLearen Shell
3043 Centreville Road
Herndon, VA 20171
(703) 318-7744
http://www.mclearenshell.com