AUTONET TV BLOG

Idle Talk about Engines (Causes of Rough Engine Idling)

When you slow down at stoplight, your vehicle's idle should be smooth as silk.  But what happens when the engine is missing or idling roughly? That's your engine's way of telling you, "Hey, I've got something wrong with me and if you don't get someone to find out what it is, I may not start the next time you turn the key."

You can help your service facility if you can describe the problem in detail.  Here's a list of things to make a note of:

• When is the problem happening, when the engine is cold or when it's been running for a while?
• Does the rough idling occur when I'm accelerating or when I'm going at a steady speed?
• Does it happen at high speeds?  Does it happen low speeds? Does it happen at both?

Make sure you describe the problem in as much detail because it will help a technician diagnose the problem.

One of the first things they'll check is how the spark plugs are firing.  Modern iridium plugs are supposed to last a long, long time.  But they CAN eventually wear out.  Inspecting the firing end can help the technician figure out the root of the problem.  Corroded or worn out spark plug wires, too, can contribute to an idling irregularity. 

There are other potential problem spots, too.  The technician may check the ignition coil, timing piston rings, valves and cylinder walls. 

If the mixture of air and fuel isn't correct, that may affect how smooth your vehicle is running.  Your service facility is equipped with diagnostic equipment that helps them pinpoint the problem.  Once that idle is smoothed out to the way it used to be, you'll be the smoothest operator on the road.

Garrigan's Auto Repair Shop
6465 E GOLF LINKS RD
TUCSON, AZ 85730
(520) 572-7505
http://garrigansautorepair.com

The Truth about Tire Pressure (Tire Inflation)

Most light vehicles (under 10,000 pounds/4,500 kg) in North America sold from 2008 model year on have a feature that many people are confused about.  It's the tire pressure monitoring system (TPMS).  You may have some experience with it yourself if you own a newer vehicle.  Vehicles with TPMS have sensors in each tire that are supposed to warn the driver when tire pressure gets dangerously low.  That's important because tires that are significantly under-inflated can cause very serious accidents.

Unfortunately, many drivers think the TPMS does all the work keeping track of tire pressure. To them, as long as the warning light or gauge isn’t giving a warning, the tires must have the proper amount of air pressure in them.  That's not the case.

Tire pressure monitoring systems aren't all created equal.   Some give you a digital readout of the pressures in each individual tire.  But many simply have a warning light that looks like the cross section of a tire with an exclamation point in the middle.  If you don't know what it is, it's because it's not instantly recognizable as a tire.  In fact, one company that makes TPMS, Schrader Performance Sensors, surveyed drivers.  Their study showed that more than 40 percent of drivers didn't know that that warning light was. 

One out of 5 of the drivers who did know what the light was only looked at their tires after the light came on to see if they could see any that needed air; they never checked them with a tire gauge or had someone else do it.  Ten percent of them didn't do anything when the light came on.

In most vehicles with TPMS, the warning comes on only when the tires are more than 25% underinflated.  The American Automobile Association says that's under the pressure you need for safe vehicle operation.

The bottom line is once a month you should make sure your tires are inflated to the manufacturer's recommendations.  That means each tire should be measured with an accurate, external tire gauge.  To be confident you are getting a correct reading, take your vehicle to a reputable service facility where their equipment is calibrated and they know what they're doing.

Severely underinflated tires can contribute to an accident that kills or severely injures people.  The idea behind TPMS is well intended, but the system was never meant to replace regular inflation measurements and maintenance.  Periodically have your tires checked for proper inflation.

Garrigan's Auto Repair Shop
6465 E GOLF LINKS RD
TUCSON, AZ 85730
(520) 572-7505
http://garrigansautorepair.com

Start Me Up (Ignition Systems)

When you start up your gasoline engine car, you may not know that it's using the same ignition principles as it has for decades.  You have spark plugs that require enough power so a spark can jump across a gap at its tip.  Years ago, a vehicle's 12-volt system had to produce 15,000-25,000 volts to do that, so engineers came up with something called an ignition coil that bumps up the voltage. It also has to be done at just the right interval called timing.

The first systems had a distributor, a mechanical device with a rotating disc that switched the power to the ignition coil on and off.  That higher voltage then was sent to the spark plugs at the correct time interval. But the mechanical "points" had to be replaced and adjusted every 12,000 miles/20,000 kilometers.  Engineers later replaced the switching mechanism with solid state ones, but they still needed replacement after 120,000 miles/200,000 kilometers.

The next evolution came in the 80's when the distributor was replaced with a couple of sensors which talked to a computer.  This "DIS" (distributor-less automotive ignition system) was a big advance.  Plus, it didn't use just one ignition coil for all the cylinders.  It had coil "packs" that each provided spark to two cylinders.  That way, the voltage could be boosted even higher, to 30,000 volts, which helped engines be able to ignite a leaner fuel/air mixture.

Recently have come even more improvements.  Now instead of coil packs, there's a coil that's attached to each spark plug.  No more spark plug wires means less maintenance. Plus, a stronger, hotter spark of 50,000 volts can make an engine more reliable, increase fuel economy and reduce emissions.

No matter what ignition system your vehicle uses, your vehicle service facility has a staff of technicians trained to work on the latest technology.  Make sure to have your vehicle maintained regularly so you can take full advantage of these modern engineering marvels.

Garrigan's Auto Repair Shop
6465 E GOLF LINKS RD
TUCSON, AZ 85730
(520) 572-7505
http://garrigansautorepair.com

It Pays to Take Care of Your Transmission at Garrigan's Auto Repair Shop

If you've been paying attention, you've noticed that vehicle engines are getting more and more powerful in TUCSON. At the same time, they are getting better and better fuel economy. I've gotta tell 'ya, most of that's because of technological advances in transmissions. To get a better understanding of why that is, let's talk bicycles.

You've probably seen plenty of cyclists on TUCSON roads. Perhaps you ride yourself. Then you know that a cyclist's cadence is the number of times per minute he or she pedals. The ideal pedal speed is the zone where they can most efficiently generate power over a sustained period of time. The experienced AZ cyclist uses her gears to keep her pedal speed in the ideal zone whether she's climbing a hill, cruising on a flat stretch or killing a downhill.

Think of it this way: if you have a 1-speed bike, you really have to pump hard to get up to speed. Your top speed is limited by how fast as you can pedal. And if you're climbing a steep AZ hill – forget about it.

Now let's add a couple of gears: one lower and another one higher. With the lower first gear, you can get up to your ideal pedal speed more quickly. When you shift to second, your pedal speed drops below ideal for a while as you work to get back to peak efficiency. Same thing happens when you shift to third, but now you can go much faster than you could with a 1-speed bike using the same effort. Add more gears and you can see that it's much easier to maintain ideal pedal speed. The result, quicker starts, better hill climbing, higher top speed and, most of all, a lot less fatigue for the TUCSON rider.

Like a cyclist on a bike, every vehicle engine has an ideal engine speed called its power band. When an engine is running in that zone, it can make power very efficiently. It's the vehicle transmission's job to keep the engine in the power band over a wide range of operating conditions. Today 5 or 6 speed automatic transmissions are pretty much the minimum, and 7 and 8 speeds are fairly common in TUCSON.

Obviously these sophisticated transmissions are very expensive. In fact, next to your vehicle engine, your transmission is the most expensive component in your vehicle, so it pays to take good care of it. Your manufacturer has a recommended service interval for changing your old, contaminated transmission fluid. Servicing your transmission on schedule at Garrigan's Auto Repair Shop keeps it operating at its best and can prevent costly damage. Ask your friendly and knowledgeable Garrigan's Auto Repair Shop advisor if it's time for transmission service. Come see why smart TUCSON drivers trust their transmissions to Garrigan's Auto Repair Shop.

Give us a call.

Garrigan's Auto Repair Shop
6465 E GOLF LINKS RD
TUCSON, AZ 85730
(520) 572-7505
http://garrigansautorepair.com