AUTONET TV

Tacky or Techie? The Tachometer.

There's a gauge that many vehicles have that says RPM on it.  And there are a lot of people who either don't pay any attention to it or don't even know what it is. Here's why it's a good gauge to know about.

It's called a tachometer, and that "RPM" label means it is measuring how many revolutions per minute (RPM) the engine is turning.  Automotive experts know that a vehicle's engine can be damaged if it turns too fast (revving too high) or too slowly ("lugging" the engine).

A tachometer (sometimes called a tach) is almost a "must-have" gauge for vehicles with a manual transmission; the driver has to manually change gears; the tach helps the driver know when revolutions are in the optimal range.

Some say you don't need a tachometer if you drive a vehicle with an automatic transmission. It's true that most drivers of automatics don't even look at it.  But there are times when paying attention to the tach can help you prevent an expensive repair.

Here's a good example.  Manufacturers now build many of their automatic transmission vehicles with shift paddles.  They let you shift gears without a clutch. That's manual shifting, and drivers need to know they're not revving the engine too high. That's where the tachometer comes in, since it shows you visually when you are in the red zone (RPM too high).

Here's another way the tach can help you: fuel economy. Generally speaking, the lower the RPM, the better the fuel economy. It's not good to go too low, of course, and the tachometer will help you find that spot of maximum efficiency.

You can also spot problems by paying attention to the tach.  When your vehicle stays in first gear longer than usual (higher reading on the tach), then the RPM dip lower than usual after shifting, it may be that your vehicle's transmission is skipping a gear.  Plus, if your vehicle's RPM go up but your speed doesn't, it could mean your transmission is slipping.  Either situation should be checked by a trained technician.

If your commute takes you down some long grades, you might like to put your vehicle in a lower gear to help slow down the car (and not burn up the brakes). Having a tachometer keeps tabs on when your engine is revving too high.

So, consider the tachometer a "bonus" gauge.  It's one more helpful assistant that can help you spot and prevent problems in your vehicle.

Positive Crankcase Ventilation ? PCV Valve Service at American Brake Centers Inc.

Hello Louisville! Did you know that the first federally-mandated emissions control device was introduced in the 1960's? The Positive Crankcase Ventilation valve, or PCV valve, has been installed in KY vehicles since 1964 and represents the first legislation by the United States government to regulate harmful emissions as well as to improve performance in the country's vehicles.

The PCV valve, as you can probably guess, is located on the crankcase. The crankcase is the lowest part of a vehicle's engine. It houses the crankshaft and the engine oil. The crankshaft connects to the pistons that power the engine.

Pistons are pushed down when fuel is burned in an engine. This causes the crankshaft to rotate, which sends power to the transmission.  It ultimately turns the axles and causes the vehicle to move. Some of the gases released by the burning fuel squeeze around the pistons and down into the crankcase.

If the escaped gases mix with the engine oil in the crankcase, oil sludge develops. This sludge has the consistency of petroleum jelly and can cause damage by clogging up passageways in the engine. Further, escaped gases can build up pressure inside the crankcase that can blow out seals and gaskets.

Before 1964, a hose was attached to the crankcase that vented escaped gases out into the air. These gases contained about 70% unburned fuel as well as harmful emissions. The PCV valve was designed to curb these harmful emissions as well as recapture unburned fuel.

The PCV valve is a small, one-way valve that allows escaped gases to exit the crankcase. The gases are then routed into the intake system so they can be re-burned in the engine. Fresh air enters the crankcase through a breather tube to facilitate this circulation and keep the air in the crankcase clean.

The PCV valve, like most working parts on a vehicle, will wear out over time. Usually it simply gets gummed up. Preventive maintenance, including routine oil changes at American Brake Centers Inc. in Louisville, will extend the life of the valve, but eventually it will have to be replaced. A sticking PCV valve won't allow gases to circulate properly, which can increase pressure in the crankcase. Over time, that pressure will lead to oil leaks.

Your vehicle manufacturer recommends that a PCV valve be replaced every 20,000 to 50,000 miles (32,000 to 80,000 kilometers), depending on the vehicle and Louisville driving conditions. It's an inexpensive repair but may not be included in the maintenance schedule in your owner's manual.  So if you're looking for auto advice about the PCV valve, you may have to ask our pros at American Brake Centers Inc..

Taking care of our PCV valve protects the environment in KY and improves vehicle performance. It's just part of good vehicle care for Louisville drivers and a way all of us can do our part to improve the world we live in.

American Brake Centers Inc.
3435 Bashford Ave Ct.
Louisville, KY 40218
502-459-0355
http://www.americanbrakecenters.biz