Allen Auto Repair

When you hear hissing sounds coming from your vehicle, you might start thinking the worst.   One type of hissing coming from around your air conditioner may be a normal sound, or it could be a sign of serious trouble. First - the normal sound.  When you turn off your vehicle, the refrigerant goes from its high-pressure side to the low-pressure side. Some of those noises are normal.  But when it hisses all the time, that's another story. One cause could be that the refrigerant is leaking.  Air conditioners are fairly complex systems that involve various pumps, hoses, valves and motors.  When your air conditioner is cooling, the refrigerant changes from a gas to a liquid and back.  That refrigerant is under pressure, and there are many places it can leak from.  A hissing sound can also be a failed valve in your air conditioner's compressor.  It is what controls the refrigerant's pressurization.  It's important to have this fixed fairly qu ... read more

You may notice that when you get your vehicle's oil changed, your service adviser may recommend that you have your tires rotated at the same time.  The reasons are simple.  That will allow your tires to wear more evenly and reduce the noise your tires make as you drive down the road. There are different ways of rotating tires. If your vehicle has non-directional tires and the same size wheels at each corner, here are the different rotation patterns. For all-wheel drive and rear-wheel drive vehicles, one is called the rearward cross pattern.  The rear tires are moved to the front and stay on the same side of the vehicle, and the front tires are moved to the rear on the side opposite of where they were on the front.  For all-wheel and four-wheel drive vehicles, use the X pattern.  The rear tires are moved to the front on the opposite side of the vehicle, and the fronts are moved to the rear on the opposite side of where they were on the front. For front-wheel dri ... read more

You know how exposing your skin to sunlight can cause sunburn and other unhealthy things.  Sunlight can also create major problems for your headlights.  After they've been exposed to ultraviolet light, acrylic headlights can yellow and fog due to oxidation.  And when that happens, less light can pass through the plastic, reducing the effectiveness—and safety—of your headlights.  It's not just the UV light that causes headlights to turn cloudy.  Road grime and debris gets kicked up and can scratch the plastic, diffusing the light that should pass through them when they're clear.  Plus, when your vehicle was new from the factory, the headlights had watertight seals all around to prevent moisture from getting into them and fogging them up with water vapor.  Just like clouds can hide the sun, tiny water molecules can diffuse the light from your headlight bulbs.  Sure, you could buy replacement parts and start fresh.  But the good new ... read more

Most of us know a bad muffler when we hear it.  That loud, rumbling sound is unmistakable. Did you also know you can get a ticket for driving around with a loud exhaust system? If your exhaust system has a leak in it, it may be allowing poisonous gases inside your vehicle and could make you seriously ill (or even kill you!) if you breathe too much in. Unfortunately, your exhaust system faces a lot of destructive forces out on the road.  Rust is the worst, and not just in colder climates where they use salt and brine as de-icers.  Exhaust systems can rust from the inside out when moisture condenses inside the pipes.  Vibrations and jolts from rough roads (and the occasional run in with a rock or a curb) can wreak havoc with exhaust systems.  Even a bad oxygen sensor can send too much fuel into the catalytic converter, and the resulting heat can wind up destroying this very expensive component. Your exhaust system is made up of several parts, and all need to be i ... read more