Rockville Auto Repair

Your vehicle's air conditioning is something you count on when the weather heats up.  But there's bound to be a day when you turn it on and one of these things happens: Only warm air blows out Cold air starts blowing out but then it turns warm on its own It's not blowing air at all It blows smelly air out Some people are tempted to try to make the diagnosis—and the repair—on their own.  They think it's just run out of refrigerant and they can pick up a can at a local auto parts store and re-charge it.   If only it was that easy. A vehicle's air conditioning system is complex and made up of many parts.  A compressor, evaporator, condenser, tubing, hoses, sensors, valves… the list goes on and on. Each of these components could be the reason for the problem.  It could be a leak that's letting the refrigerant escape, but simply re-charging the system hasn't fixed the problem. You have to find the source of the leak and fix it. Service faci ... read more

When it comes to your vehicle, driving it too much can cause some issues.  But what about not driving a vehicle enough? That has consequences as well. Here are a few things that can happen if a vehicle isn't driven enough.  When the engine doesn't operate, the oil isn't lubricating. That means some mechanisms that need periodic lubrication aren't getting it.  And oil that sits around breaks down over time.  In fact, some experts say you should change oil more often if your vehicle sits in the driveway than if you drive it regularly.  You've heard that expression, "Take it on the highway and blow out the engine.” Well, carbon buildup used to be a problem in older vehicles.  But the real culprit these days is moisture that builds up from combustion if your vehicle never gets hot enough to burn it off. That water vapor can mix with oil and cause sludge to form. There are many vehicle systems (battery, exhaust system, engine seals, etc.) that benefit fro ... read more

You know how heavy your engine and transmission are, so you can imagine how tough the parts that hold them onto your vehicle's sub-frame must be.  Not only must they support the weight, they also have to isolate vibrations and noise from the passenger cabin.  Pretty tall order, wouldn't you say? The parts that face that task daily are called the motor mounts, or engine mounts.  They are usually made of rubber with steel brackets.  Others contain a liquid for vibration and sound isolation.  Most vehicles have three or four motor mounts, and while rubber or hydraulic liquids do a good job of damping the vibrations from the engine, they also have their limitations.  The problem with rubber is that it gets old and brittle.  Plus, if there's an oil leak anywhere in your engine and oil gets on the rubber motor mounts, rubber will deteriorate even more quickly.  As for the liquid motor mounts, they can develop leaks and stop working.  Here are sign ... read more

Ever wonder what one of the best things is to ever happen to your vehicle's engine?  It's the little thing that usually looks like a can, the oil filter. Just like your kitchen sink strainer filters out errant particles of food from clogging your drain, the oil filter cleans out small particles that could cause your engine harm. Your engine operates in a dirty, hot environment and gathers a lot of tiny contaminants like dirt, dust, little metal shards and unlucky bugs that get sucked in.  Get those things circulating in your engine and those little particles can cause friction, which starts wearing out those finely machined metal parts.  You know how important it is to change your oil regularly.  It's vital that you change your oil filter at the same time to keep the oil as close to brand new as possible. Most oil filters look like a metal can with some holes in the bottom.  Inside there are carefully chosen materials that can screen out the contaminants while ... read more

You've probably never paid much attention to the writing on the sides of your tires, but they contain a wealth of information.  There's a long combination of letters and numbers that can tell you a whole lot about what tires your vehicle was designed to be riding on.  Let's check out this example found on an SUV: P245/70R17 108T. The first letter, P, means it's intended for passenger vehicles.  If there's no letter, it means it's a metric tire.  If there's an LT at the beginning or end that means a tire designed for light trucks. Moving on to our example, the 245 shows how wide the tire is in millimeters from sidewall to sidewall.  The number that follows in our example, 70, means the height of the tire is 70% of its width.  The letter after that in our example, R, describes the type of tire (on this vehicle, radial).  Following that is the diameter in inches, in our SUV example, 17 inches.  How much load the tires' sidewalls are designed to take ... read more

If you’ve noticed your vehicle is hard to start, stalling, or has lost power, the culprit may be a part with an odd name: the MAF sensor.  You may have never even heard of a MAF sensor, but it’s important that it be working correctly, or you may be experiencing some fairly significant engine issues. All vehicles bring in air and direct it through an air filter before it goes into your engine, where it mixes with fuel to provide power to get you going. There’s a tube-like device with a sensor inside it that measures how much of that mass of air is passing through. That’s why it’s called a mass air flow sensor, or MAF sensor.  If the MAF sensor isn’t working right, the engine’s computer can’t figure out the right amount of fuel to mix with it, and your engine may hesitate or stall.  Sometimes this will cause your Check Engine Light to come on, and any time it does that, make sure you have your vehicle checked by a professiona ... read more

If you've ever ridden down a rough road on your bicycle, you know how hard a ride it can be.  Yet drive down the same road in your car, truck or SUV and it miraculously will smooth out the ride.  That's because it is equipped with shock absorbers.  They are built to dampen impacts from road irregularities.  But after taking hundreds of hits from potholes, railroad tracks and curbs, your shock absorbers can wear out.  Besides the rough ride that can cause, there are other ways your vehicle's performance can be affected. When it comes to braking for example, you may take a longer distance to stop.  That's because shocks help keep your tires in contact with the surface of the road.  If the shocks aren't working properly, the tires won't make contact like they should.  So when you slam on the brakes, your vehicle will take longer to stop. Consider what worn out shocks are doing to your tires.  Since the bumps aren't being dampened as much, your ... read more

There's nothing quite like getting in your vehicle on a hot day, switching on the air conditioning and having warm air blow out of the vents.  You may have had no problem for months and then, one day, you are driving around in a sauna. You're hot stuff, but not in a good way! So what goes wrong when the AC isn't working? It could be a lot of things because the system has many different components.  One thing that's a common cause is the vehicle is low on refrigerant (it used to be called Freon).  If that's the case, it's not as simple as simply adding more.  Sure, it may fix it quickly for a short time, but it's more likely than not that the refrigerant will just leak out again. The original Freon used in air conditioners was destroying the Earth's ozone layer, so that's not used much any more.  But the one that's currently used also contributes to global warming, so it's important that as little of that escapes as possible.  So a technician will determine ... read more

Driving along, your exhaust system's rumbling so loud that people turn and stare at you pass by.  You're wondering when the police are going to pull you over for illegal noise. Your mind immediately thinks, aha! A broken muffler.  Well, your exhaust system is composed of many more parts than just a muffler.  Your engine makes power because of thousands of tiny explosions from detonating fuel.  Those explosions make a racket, so engineers came up with a system that acoustically dampens that sound in addition to getting rid of harmful exhaust. In the engine is the exhaust manifold that looks like several pipes that join up into one pipe.  It directs exhaust to the catalytic converter. The catalytic converter converts harmful gases into less harmful gases using certain chemical reactions.  Then comes the muffler that has baffles inside to quiet the sounds of your engine noise.  Finally: the tailpipe. All of those pipes and parts are joined together by cl ... read more

Your vehicle may be like that famous battery bunny, the one that just keeps going and going.  But while it may seem sometimes like you never need to take your vehicle in to be worked on, there are some things you should keep your eyes, ears and nose out for. They are warning you about something that needs attention at your vehicle service facility. If a warning light is on, don't ignore it; do something about it.  There are warning lights for battery, oil, engine heat, tire pressure… you name it.  And the manufacturer put them there for a reason.  They're telling you something isn't normal. So when one goes on, have it checked out soon, especially the blinking Check Engine light.  The earlier you have any warning light issue diagnosed, the more likely you are to avoid a more serious problem. If your vehicle is vibrating or shaking, it's not only annoying, it could signal trouble.  You can bet your vehicle didn't do that when it came out of the fact ... read more