Rockville Auto Repair

There's a belt that snakes through your engine.  It's even named for a snake, the serpentine belt.  It'll bite you when it breaks, possibly leaving you stranded.  So, it's good to know a little about this snake-like belt. In early engines, there were lots of belts. They were used to convert the rotating power of the engine to turn a mechanical part.  But engineers had an idea.  Why not consolidate all those belts into one that ran a bunch of different parts simultaneously? Voila!  The serpentine belt. It's found in the front or side of your engine unlike older belts which were often in a V shape, the serpentine belt has ribs on it which more effectively connect with the pulleys that power the other components.  A serpentine belt may power the water pump, power steering pump, alternator, and the air conditioning: all from one crankshaft.  Now, all that's fine when everything is working well and the belt is intact.  But when a serpentine belt ... 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

Your vehicle is loaded with electrical devices. Computerized components are everywhere, so good electrical connections are important.  Those begin with your vehicle's battery, so it's important that its connections are in top shape. Ever had a flashlight that didn't work, took out the old batteries to replace them and noticed the old batteries were all corroded? The same thing can happen to your vehicle's battery.  The battery type used in most vehicles is a lead-acid, which can be very corrosive.  Corrosion can build up around your battery's terminals that can prevent the electrical connection from being as solid as it needs to be.  You may have even seen discoloration around your battery's terminals if you look under the hood, a sign of corrosion. Or you might notice visible signs of fraying or loose battery cables. All of your vehicle's components are affected by vibrations from the engine and road surface imperfections, and the battery cables take a lot of jostl ... read more

You know that sinking feeling when you realize one of your tires has a problem.  It may be making an odd noise or behaving oddly when you're driving.  You may hit a pothole or curb and one suddenly goes flat.  Or you may head back to your vehicle and discover it has one tire deflated without a clue of what must have happened to it. With a lot of different tires hitting the streets these days, the issue of whether to have a tire repaired or replaced can be tricky, and we strongly recommend you have a trained technician help you make that decision.  One of the most common causes of flat tires is picking up a screw or nail in the tread area.  Many of those can be patched and plugged if the puncture isn't more than ¼ inch/6 mm in diameter. Most tires can handle two of this type of repair, but any more and you should buy a new tire.  If there's a puncture or bulge in the sidewall or shoulder, the rule of thumb is it's not repairable.  The sidewall d ... read more