Rockville Auto Repair

It's easy to get letters like PVC and PCV mixed up.  PVC is a plastic that's used in a lot of things, especially plumbing pipes.  And PCV is a valve that helps your engine burn off excess fumes rather than having them pollute our atmosphere.  PCV stands for positive crankcase ventilation.  When your engine ignites gasoline in the cylinders, some of the gases produced make their way into the crankcase, where oil is held to lubricate the engine.  In earlier days, those gases would be vented out through a hose and go directly into the air.  It was a waste of gasoline (since about three-fourths of the gases were unburned fuel) and a nasty source of pollution. So engineers devised a one-way valve that directed those gases back into the engine's air intake system to be burned again.  After a while, the PCV valve can get clogged up with gummy oil.  Not only does that reduce the recirculation of the gases, but it can also cause pressure in the crankcase ... read more

When you're driving and turn a corner, you probably aren't aware of all that's going on with your wheels.  The outside wheels have a longer distance to travel than the inside wheels, so there are gears that allow the wheels to go at different speeds when you turn.  That set of gears is called a differential.  In front-wheel drive vehicles, it's by the transmission and called a transaxle.  Rear-wheel drive vehicles have the differential, naturally, on the rear axle. Many all-wheel and four-wheel drives add a center differential since power has to go to the front and rear wheels. (Some newer vehicles power wheels with electric motors, but that's a whole different story.) Time and distance traveled eventually can take their toll on the differential, and you may notice some noises you hadn't heard when your vehicle was newer.  Sometimes you'll hear a whir that might change in pitch when you turn.  You may hear clicking sounds when you're moving.  Others d ... read more

Seems like these days, we're hearing about more and more electric or hybrid vehicles.  Keep in mind that conventional gasoline internal combustion vehicles have important electrical components, too, and it's important to make sure they're operating at their peak. In a vehicle with a gasoline engine, the part that keeps the battery charged is the alternator.  It converts the mechanical energy created by the engine into electrical power.  To do that, a shaft in the alternator has a pulley on one end that's driven by a belt that is turned by the engine.  A series of magnets then spins around coiled wires and it creates alternating current, or electricity. Your vehicle uses that to charge the battery that, in turn, keeps other electrical components in your vehicle working. Here are a few signs that the alternator isn't doing its job right.  The battery keeps going dead, your instrument panel's battery light is on (it looks like a rectangle with a - and + inside and ... 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