Allen Auto Repair

Can you think of anyone who likes getting a flat tire?  Of course not.  But when one of your tires winds up with a flat or leak, whether it be from things like hitting a curb, running over a nail or picking up a sharp stone, it's time to have someone who knows what they're doing take care of it. If you're thinking you'd like to avoid having to buy a new tire, you wonder if a patch or plug will suffice.  It depends where the puncture is and how big the hole is.  Most tire experts will say if the hole in the tire is less than ¼ of an inch or 6 mm, a patch can work.  But a patch likely won't work if the compromised part of the tire is on its shoulder or sidewall. Here's why.  The shoulder of a tire is the part between the sidewall and tread and it's usually rounded.  It's under a lot of pressure, more than even the sidewalls. And because of that curved shape, it's hard to get a patch or plug to hold. The sidewall is the side of the tire.  Sid ... read more

Your vehicle’s engine runs hot.  It should, since it’s a series of little explosions that create the power that gets you going where you want to go.  To keep the engine cool, engineers have designed wonderful cooling systems that use liquid coolant, hoses, and a radiator to transfer the heat from the engine to the outside air.  In order for the system to work right, it has to have the right amount of that liquid coolant in it.  So that you know when the coolant has dipped below the correct amount, there is a sensor that keeps an eye on it.  When the coolant gets low, that sensor lights up a signal on the dash to alert you.  It may literally say “Check Coolant” or it may have a picture that looks like an old-style bulb thermometer sitting in liquid.  Your owner’s manual will usually tell you exactly what the one in your vehicle looks like. If that sensor system isn’t working right, you could wind up driving for a lo ... read more

In a perfect world, all wheels and tires would be perfectly round and weigh exactly the same at every point of the wheel.  Unfortunately, they're not, and if they're out of balance, they can reduce the lifespan of your tires, make your vehicle shake like a carnival ride, and maybe even damage a few suspension parts along the way.  You don't want that! Wheel balancing, sometimes known as tire balancing, is a process by which a technician makes sure your tire/wheel assembly has evenly distributed weight.  If it isn't, it can give your ride bad vibrations.  If you feel your vehicle's steering wheel shaking, it can mean unbalanced wheels in the front. If you can feel a vibration in your seats, it could be unbalanced rear wheels. In addition to your vehicle vibrating at higher speeds, there are other signs that your wheels are out of balance. You may see uneven tread wear, or you may notice you aren't getting the kind of fuel economy you used to.  When you experienc ... read more

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

Most drivers love how easy it is to turn their vehicles, and they have power steering to thank.  Engineers have figured out a way to take some of your engine's power to help you turn. Without it, steering can be quite a chore.  New power systems are electric, but there are still plenty of the older hydraulic power steering systems out there, and it's wise to keep them working the way they should so you don't find yourself stranded without power steering. Those hydraulic power systems use a fluid under pressure that is pumped to a device that helps you turn your wheels more easily.  It's that pressure that presents the challenge.  After your vehicle's seen a few years on the road, you may find your steering isn't quite as easy as it was.  You may hear a groaning or humming sound when you turn.  One component that can fail is the pressure hose that carries that fluid from the power steering pump to that turning assist mechanism.  The hose is made of rub ... 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

Every day you drive, you're sitting behind the dashboard. But how in the world did it get that name? Back in the days of the horse-drawn carriage, horses would kick up dirt and mud on the driver and passengers, "dashing" debris against the carriage. So those who built carriages began installing a board to protect them. So, dash-board. Dashboard. The dashboard is still there, though changed quite a bit from the early days. Now its main purpose is to house the controls and instruments for your vehicle's systems. Of course, you have the speedometer, tachometer and gas gauge. But there are four warning lights you need to pay attention to on your dashboard and instrument panel. Some of these may even be gauges, depending on your model of vehicle. Regardless, paying attention to them is a good idea if you want your vehicle to keep going as long as possible. Oil pressure—The oil pressure light will come on if your engine doesn't have enough pressure in its system. Low oil pressure means ... read more

If you've ever felt your vehicle hesitate, go, then hesitate again, you might think there's something wrong with the transmission.  After all, it's not moving smoothly  down the road.  But there are plenty of malfunctions that can cause those symptoms, one of them being something you may have never heard of: the EGR valve. EGR stands for Exhaust Gas Recirculation. It's a system that channels small amounts of exhaust back into the engine to cool down the cylinders and reduce polluting gases.  Those include nitrogen oxides that can cause smog. The EGR valve regulates how much of the vehicle's exhaust gas is recirculated. After years and long distances traveled, that valve can get clogged or fail. Sometimes the EGR valve can stick open.  When the EGR valve isn't working properly, your vehicle can start releasing those nitrogen oxides and pollute the air. The symptoms of a malfunctioning EGR valve include: Engine losing power Engine idling roughly Pinging and knoc ... read more

You probably have heard that expression, "A stitch in time saves nine." In other words, if you fix an issue at its early stages, it will prevent a much more difficult problem later. That's certainly the case with your vehicle, and here's a true story to demonstrate it. A driver noticed his vehicle was due for an oil change, so he took it in to his service facility early in the morning so he could wait while the work was performed. The technician routinely checks the battery on vehicles just before extreme weather is approaching (cold or hot), so with winter coming up, he hooked up the load tester (it measures voltage while a load is put on the battery). It showed the battery wasn't holding a charge well. The technician checked the manufacturing date on the battery, too (most batteries have a date stamped in code somewhere on them). The date showed it was five years old. While batteries can last more than five years, many technicians say you should expect to get anywhere from three to s ... read more