Go With the Flow (MAF Sensor Replacement)

A driver brought her vehicle into the shop the other day and told us how she was getting lousy fuel economy and that the engine was running rough.  Plus, the Check Engine light was on.  Our technician checked the code the engine had generated (why the Check Engine light was on) and found the problem.  It was a faulty Mass Air Flow sensor, MAF sensor for short.

This MAF sensor is an important part of your vehicle.  What it does is calculate the amount of air going into your engine.  As you may know, air is taken into your engine where it's mixed with fuel.  Then, the spark plugs fire, that explosive fuel/air mixture detonates, and all these sequential explosions together provide the power to get your vehicle moving down the road. 

It makes sense that if the MAF sensor isn't sending the engine's computers the correct information on the amount of air going in the engine, the fuel/air mixture isn't going to be right. It will either too rich (too much gasoline for the amount of air) or too lean (not enough gasoline for the amount of air).

In this driver's case, the MAF sensor was damaged and needed to be replaced.  Another thing that may cause the MAF to give an incorrect reading is if its wires are dirty or faulty.  So, replacing or cleaning the wires important as well.

Other symptoms that your MAF sensor is bad? If your engine hesitates when you step on the gas, it stalls, or your vehicle is jerky when you accelerate. 

A malfunctioning MAF sensor is not just bad for performance.  Driving with your vehicle in that condition can cause more damage to your engine.  When you bring your vehicle in for us to check, a technician will thoroughly examine your engine to make sure all issues are taken care of.

Matt Davis Auto
875 US Highway 70 W
Garner, NC 27529
(919) 600-5125
http://www.mattdavisauto.com

Breathe Easier (Cabin Air Filter)

When you get in your vehicle, how does it smell? If it's not so nice, it may be time to have your cabin air filter changed.

It's not the same one that filters out the air used in the engine.  The cabin air filter screens out dust and other particulates from the outside air so when it enters the cabin, you don't have to breathe them in when you're driving.  Maybe your commute finds you traveling along dusty rural roads, or maybe you pass by some city factories that have smokestacks spewing out smoky exhausts.  Or in spring, maybe you notice your allergies acting up because of the pollen in the air.  The cabin air filter will remove a lot of those things.

The more it filters out, the more those small particles add up.  That reduces how much airflow the heating/air conditioning system can handle, and you may notice not as much air is coming through your vehicle's vents.  That can also be a sign you need your air filter replaced.

Our technicians will remove and inspect the air filter; it's usually located around the glove compartment, under the dash or sometimes in the engine compartment. If you wish, your service advisor can show you what condition yours is in; if it needs replacing, you'll be able to see the dirt, bugs, leaves and other crud that accumulates after several months of driving. 

Each vehicle's manufacturer recommends an interval after which your cabin air filter should be replaced. Depending on how much and where you drive, you might find yourself needing a replacement more or less often than the manual suggests.

Just like you clean your furnace filters periodically, it's wise to do the same with your vehicle.  After you do, you'll find you might just breathe easier!

Matt Davis Auto
875 US Highway 70 W
Garner, NC 27529
(919) 600-5125
http://www.mattdavisauto.com

Shifty Letters PRNDL (Transmission)

You probably figured out those shifty letters.  They're what you see on your automatic transmission shifter and stand for Park, Reverse, Neutral, Drive and Low.  Your automatic transmission is one of the great automotive inventions; here are some ways you can keep yours working well.

Maintain your transmission regularly.  A technician will check your transmission fluid's level and even its appearance and smell.  If it's dark or has an unusual odor, that could be a sign of trouble.

Change from one transmission direction gear into another only when your vehicle is stopped.  So many drivers want to switch from Reverse to Drive quickly or the other way around.  If you do that when the vehicle is moving, you can damage your automatic transmission.

Keep your vehicle's cooling system in top shape.  What does the cooling system have to do with the transmission? It helps keep the transmission fluid from overheating. 

Follow the manufacturer's recommendations for maintaining your transmission.  Some recommend at least an annual checkup by a trained technician. 

Let your powertrain warm up a little before overtaxing it. Especially in cold weather, don't step on the throttle too aggressively before all components are warmed up.  That way both your engine and transmission will last longer.

Transmissions can be costly to fix.  If you treat your powertrain with respect and regularly maintain it, you'll not only avoid expensive repairs, but you’re also much less likely to find yourself stranded because of a transmission problem. 

Matt Davis Auto
875 US Highway 70 W
Garner, NC 27529
(919) 600-5125
http://www.mattdavisauto.com

Bad Vibrations (Brake Rotor Replacement)

If you’ve ever stepped on your brake pedal and felt your vehicle vibrate, that’s a signal that you shouldn’t ignore.  A pulsating brake pedal is a sign that something is wrong.  Braking action should be smooth, sure, and quiet, not shaky and noisy.

Most newer vehicles have disc brakes, called that because they have a round, flat disc connected to each wheel.  Those discs are the rotors. Other parts called brake pads are squeezed against those discs when you press on the brake pedal.

Remember that vibration we mentioned? That can be caused by the rotor not having a straight, true surface. Rotors can heat up from friction and warp.  They can become thinner from constant wear.  Rotors can rust from the elements they’re exposed to, such as rain, snow ice, and salt.  They can get grooves in them from so many contacts with the pads. 

The signs of worn rotors are vibrations, grooves on the rotor (which you can see sometimes through open spots in the wheel) noise such as squealing or scraping when you brake, and increased stopping distance.   

While it used to be common for rotors to be machined (shaved down to restore their flat surface), newer vehicles have thinner rotors, so your service adviser may suggest you replace rotors when they start showing signs of significant wear.

Brakes are important safety equipment for every vehicle.  They enhance your control while driving, so it’s important that they be regularly inspected and maintained.  A good time is when you have your tires rotated. A technician can then look at all components of your brakes and recommend any service you may need to keep your brakes in top shape.

Matt Davis Auto
875 US Highway 70 W
Garner, NC 27529
(919) 600-5125
http://www.mattdavisauto.com