Allen Auto Repair

Ever wonder how your vehicle’s transmission is connected to your wheels? After all, when you hit a pothole or some other uneven part of a road’s surface, there has to be something that can maintain the connection between the transmission and the wheel yet keep everything moving at the same speed.  That very cool device is called a CV joint, a kind of driveshaft running to each wheel.  The CV stands for constant velocity because it keeps the drive wheels moving at a constant speed (velocity).  They’re used mostly on front-wheel drive vehicles but also in rear-wheel and all-wheel drive vehicles. The joints move up and down and adjust to bumpy surfaces.  Plus, they are covered in a rubber boot which protects them from road debris and also holds lubrication in.  There’s a CV joint and boot on the transmission side and one on the wheel side.  Unfortunately, the spot that usually fails first is that rubber protective cover (the boot).&nbs ... read more

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 contaminat ... read more

You expect your heater/air conditioner to work like it should.  You have a control for temperature and one for fan speed.  You even have a control for what vents the air comes out of.  Don't be surprised one day if your blower fan develops a mind of its own and starts going crazy.  Most of the time, you may find that it starts blowing at full speed, and nothing you do to try to control it does any good.  This is what may be happening. Your blower motor has an electronic component called a resistor.  It does what its name says; it offers resistance.  When you want the fan to run more slowly, you turn the fan speed down.  That resistor accomplishes that by turning its resistance up.  When the resistor fails, the power has nothing to slow it and the fan speeds up.  It's a small part and can fail due to age or corrosion.  It's usually not an expensive part, either, but it's often found in a location that's not that easy for the technic ... read more

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 ... read more

Who thinks about their fuel gauge?  You probably don't… until it doesn't work any more.  Then you have to guess how much fuel is in your tank, and that's no way to live life on the road.  Fuel gauges, like every other part in your vehicle, can fail.  And when yours stops working, you will probably want to head over to your service facility soon, because no one relishes running out of fuel. The fuel gauge system is much more than just the gauge you can see on your instrument panel. Most systems have a float inside the fuel tank that goes up and down depending on the fuel level.  It's called the fuel sending unit, and it sends an electrical signal to the gauge (on the dash) telling it to display how much fuel is left in the tank.  So, what could go wrong?  Well, a few things.  For one thing, corrosion from bad fuel can cause it to stick and it won't move up and down any more.  So you could fill up your tank and the gauge would still rea ... read more

There's a gauge that many vehicles have that says RPM on it.  And there are a lot of people who either don't pay any attention to it or don't even know what it is. Here's why it's a good gauge to know about. It's called a tachometer, and that "RPM" label means it is measuring how many revolutions per minute (RPM) the engine is turning.  Automotive experts know that a vehicle's engine can be damaged if it turns too fast (revving too high) or too slowly ("lugging" the engine). A tachometer (sometimes called a tach) is almost a "must-have" gauge for vehicles with a manual transmission; the driver has to manually change gears; the tach helps the driver know when revolutions are in the optimal range. Some say you don't need a tachometer if you drive a vehicle with an automatic transmission. It's true that most drivers of automatics don't even look at it.  But there are times when paying attention to the tach can help you prevent an expensive repair. Here's a good example.&nbs ... read more

In a year marked by unusually heavy flooding in North America, drivers are very aware of the possibility they may find themselves driving where water has come over the road.  It can be a daunting and frightening situation.  Flooding waters can move quickly and unpredictably, so you have to keep your wits about you when you encounter that situation. Here a sample of one vehicle manufacturer's guidelines on what to do.  First, the vehicle is designed to go through some water, but you must be careful.  Never attempt to drive through water deeper than the bottom of your tires. You can get out of your vehicle to check the depth of the water, but you can never be sure that you aren't going to drive into a spot where the road has washed away.  You can't see below the surface of the water, and suddenly you could find yourself in a place where the road drops off unexpectedly.  In swift moving storm runoff, your vehicle could literally be floating away with the curr ... read more

You may have had a friend whose vehicle was the victim of hungry rodents.  After all, mice, rats and squirrels—even rabbits—have been known to gnaw on wires in engine compartments, causing vehicle electrical systems to go haywire.  They can disable a vehicle completely and be very expensive to fix. In 2017, some drivers noticed their vehicle's wiring was being chewed and found out the automaker was using a relatively new material for covering their wires: soy.  Many of the repairs to their new vehicles weren't covered under warranty by the manufacturer when it was discovered rodents were eating the wiring.  So the owners filed a class action suit, saying the soy covering was essentially baiting the critters.  The automakers tell a different story, saying mice, rats and squirrels have been chewing through wire insulation long before it was made out of soy.  Regardless of what the insulation is made of, vehicle owners should make sure rodents are ... read more

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 gaso ... read more

You've just arrived at the store shopping and you're ready to head home.  You put your key in the ignition and… oh, no! The ignition won't turn! What do you do now? Don't panic.  There are some things you can do to get going again.  The first thing to do is see if you have a locking steering wheel, an anti-theft feature that was introduced around 1970.  Sometimes it sticks.  Move the steering wheel side to side while you try to turn the key and you might be able to get it to release.  Another thing to check is to see if your vehicle is in gear.  Most vehicles will only allow you to start the ignition if it's in park or neutral.  If you have an automatic transmission vehicle and it is in park, try jiggling the shift lever and try the key again.  Sometimes the safety mechanism doesn't properly make contact or gets a little sloppy.  If both of these don't work, it could be your vehicle's battery is dead.  Some newer electronic ... read more