Archive for February, 2012

Thompsons Auto Repair & Towing On Your Serpentine Belt

Tuesday, February 28th, 2012

Today we’re going to be talking about serpentine belts for our Mesa Arizona customers. Let’s start by talking about the accessories that are driven by the serpentine belt. First is the alternator. That’s the device that makes electricity to power the vehicle and recharge the battery. Then there’s the air conditioning compressor that makes cool air for you while you’re driving around Mesa Arizona in the summer.

The power steering and power brake pumps are driven by the serpentine belt in most vehicles. Those pumps make the pressure that assists your steering and braking.

In many vehicles, the water pump is driven by the serpentine belt. The water pump is what circulates the coolant that protects your engine. In some cars around Mesa Arizona, the water pump is driven by the timing belt.

The radiator cooling fans on some vehicles are also driven by the serpentine belt. Some have separate electric motors. That’s really a lot of work for one belt.

But modern engine design has a single belt that snakes around the front of the engine and drives most if not all of these accessories. Serpentine belts do a lot of work, but they’re tough and can last for thousands of miles.

Just how long will they last? That’ll vary for each individual car in the Mesa Arizona area. Your manufacturer will have a recommendation for when it should be changed, but it could need it sooner. The good news is that a visual inspection can reveal a belt that’s getting close to failing.

Thompsons Auto Repair & Towing can look at the belt: if it has more than three or four cracks per inch it needs to be replaced. A deep crack that’s more than half the depth of the belt – replace. Frayed, missing pieces, a shiny glazed look? It’s out of there.

What’s involved in replacing the belt? First the old belt is removed. Then a new one is fitted around all the pulleys for the accessories and the drive. There’s a special pulley called a tensioner.

This pulley is mounted to the engine block with a spring loaded arm. Its job is to apply the correct amount of tension to the belt to keep it from getting loose and maybe slipping off. Because the spring in the tensioner pulley wears out, AutoNetTV recommends replacing them at the same time as the belt. It just makes sense.

What are the warning signs that there’s a problem with the serpentine belt? You may hear a squealing sound from under the hood when accelerating around our Mesa Arizona streets. A loose belt might give you a slow, slapping sound.

What do you do if your belt breaks? If you’ve actually had that happen on our local Mesa Arizona freeway, it can be a little scary. Often the first thing you notice is that you have no power steering or power brakes. Don’t panic – you can still steer and brake, but you’ll have to do the work. It’ll be harder to steer and you’ll need more time and effort to stop, so plan accordingly.

Your dashboard will light up will all kinds of warnings. You’ll see a warning about your cooling system if you have a water pump that’s driven by the serpentine belt. This is very critical because without your cooling system working, your engine will overheat. If you don’t stop you’ll have massive engine damage, maybe to the point that you need a new engine. Pull over as quickly as you safely can. Open your windows and turn the heater on full blast to provide a little engine cooling and pulled over as soon as possible.

The battery light will come on because the alternator isn’t working. If your car’s water pump isn’t driven by the serpentine belt, you’re not in danger of overheating so you can drive a little further if necessary. But the battery will run down to the point where the car won’t run and will just shut off. You don’t want that to happen while you’re driving in our local Mesa Arizona traffic.

Remember, this does not have to happen if you replace your serpentine belt on schedule. Ask your technician at Thompsons Auto Repair & Towing to check your belts and hoses from time to time so you can take care of them if they need to be replaced prematurely.

Thompsons Auto Repair & Towing
1325 E Main St
Mesa, Arizona 85203
480-833-1071

Share

Posted in Maintenance | No Comments »

Keeping Your Mesa Air Fresh When Driving With A Clean Cabin Air Filter

Friday, February 24th, 2012

What is a cabin air filter? Is it:

A. A filter for your Mesa house?
B. A fresh, piney scent?
C. A filter for the passenger compartment of your car?

Clever you, it’s C.

A cabin air filter cleans the outside air before it comes into the passenger compartment. It filters out common Mesa air particles like dust, pollen, spores, bacteria, pollutants, exhaust gas, odors and even sparrows.

These high tech filters can block particles larger than 3 microns. By contrast, a grain of sand is about 200 microns.

Not all vehicles in Mesa have cabin air filters. They are fairly new on the scene. About forty percent of new vehicles sold in Mesa come with cabin air filters, but the number is growing every year.

Cabin air filters can make for a very nice driving environment. Your car can be a haven during our Mesa allergy season with very little dust and pollen getting into the cabin. However, the filter eventually gets clogged. When this happens, your heating and air conditioning flow can become restricted. The filter can even get kind of smelly.

Check your owner’s manual for recommended replacement intervals. Often, the owner’s manual forgets about the cabin air filter, so ask your service technician at Thompsons Auto Repair & Towing for a recommendation. It’s usually every year or 12,000 miles / 19,000 kilometers. Change it sooner if you drive in dusty conditions around the Phoenix area, or if you start to notice an odor from your ventilation system.

So keep your cabin air filter clean. It may not help with your brother-in-law in the backseat, but it will make your driving experience around Mesa more enjoyable.

Come by Thompsons Auto Repair & Towing and we’ll take a look at your cabin air filter for you.

Share

Posted in Cabin Air Filter | No Comments »

How Your Check Engine Light Works

Tuesday, February 14th, 2012

Have you ever had an experience like this in Mesa Arizona? You drive through the one of those automatic car washes. When you get to the end, where the dryer is blowing, your check engine light started flashing!

You fear the worst, but within a block or two, the light stopped flashing, but stayed on. By the next day, the light was off.

You wonder; “What was going on?” Well, it’s actually a good lesson in how the Check Engine light works.

Your air intake system has a sensor that measures how much air is coming through it. When you went under the high-speed dryer, all that air was blasting past the sensor. Your engine computer was saying, there shouldn’t be that much air when the engine is just idling. Something’s wrong. Whatever’s wrong could cause some serious engine damage.

Warning, warning! It flashes the check engine light, to alert you to take immediate action.

It stopped flashing because once you were out from under the dryer, the airflow returned to normal. Now the engine control computer says the danger is past, but I’m still concerned, I’ll keep this light on for now.

Then the Check Engine Light goes off in a day or two.

The condition never did recur, so the computer says whatever it was, it’s gone now. The danger is past, I’ll turn that light off.

Now a flashing check engine light is serious. You need to get it into our Mesa Arizona shop as soon as possible. But if it stops flashing, so you have time to see if the problem will clear itself or if you need to get it checked. How does the computer know when to clear itself?

Think of it this way. The engine control computer is the brain that can make adjustments to manage the engine. Things like alter the air to fuel mix, spark advance, and so on. The computer relies on a series of sensors to get the information it needs to make decisions on what to do.

The computer knows what readings are in a normal range for various conditions. Get out of range, and it logs a trouble code and lights up the check engine warning.

The computer will then try to make adjustments if it can. If the computer can’t compensate for the problem, the check engine light stays on.

The computer logs a trouble code. Some people think the code will tell the technician exactly what’s wrong?

Actually, the code will tell the technician what sensor reading is out of parameters. It can’t really tell you why, because there could be any number of causes.

Let’s say you’re feeling hot. You get your heat sensor out – a thermometer – put it under our tongue and in a minute or two you learn that you have a fever of 104 degrees.

You know your symptom – a fever – but you don’t know what’s causing it. Is it the flu, a sinus infection or appendicitis?

You need more information than just that one sensor reading. But it does give you a place to start and narrows down the possible problems.

There are reports on the internet telling you that you can just go down to an auto parts store and get them to read your trouble code or buy a cheap scan tool to do it yourself.

There are two problems with that. First, the computer stores some trouble codes in short term memory, and some in permanent memory. Each manufacturer’s computer stores generic trouble codes, but they also store codes that are specific to their brand.

A cheap, generic scan tool, like you can buy or that the auto parts store uses, doesn’t have the ability to retrieve long-term storage or manufacturer specific codes. Your Mesa Arizona service center has spent a lot of money on high-end scan tools and software to do a deep retrieval of information from your engine control computer.

The second problem is that once you’ve got the information, do you know what to do with it? For example, a very common trouble code comes up when the reading on the oxygen sensor is out of whack.

So the common solution is for the auto parts store to sell you a new oxygen sensor, which are not cheap, and send you off on your way. Now your oxygen sensor may indeed have been bad and needed replacing. But the error code could have come from any of a dozen of other problems.

How do you know the right solution? Back to the fever analogy, do you need surgery or an aspirin? Leave it to the pros at Thompsons Auto Repair & Towing. Give us a call at 480-833-1071 and let us help you resolve your check engine light issue.

Share

Posted in Dashboard | No Comments »

Direct Fuel Injection Update From Thompsons Auto Repair & Towing

Tuesday, February 7th, 2012

For those of you in Mesa Arizona who pay attention to these things, you may have been hearing about the new direct injection engines and want to learn more about them. Some deliver the power of a V8 with the economy of a V6.

For example, in one family of engines the conventional V6 makes about 250 horsepower. The direct injection version of the same engine makes over 300 horsepower and gets essentially the same gas mileage. The turbocharged version makes over 350 horsepower.

So what are the differences from a conventional engine?

The core difference is in the fuel injection system. The system most vehicles use now is called a port injection system. The fuel injector squirts fuel into a port just outside the cylinder where it’s then drawn into the engine with the air.

With a direct injection system, the injector squirts the fuel directly into the cylinder. The gain in power and economy come because fuel injected directly into the cylinder during the combustion cycle is burned much more efficiently.

First, the fuel is squirted in at hundreds of times more pressure, so it’s atomized much better and burns cleaner and stronger. The other big advance is in electronics. Faster engine management computers can control the additional precision required to manage direct fuel injection.

Fuel injectors are precision instruments. They have to deliver a precise amount of fuel at exactly the right time. The design of the engine also dictates a particular spray pattern for the fuel. If a fuel injector is dirty or gummed up, it can’t do its job as well. That means less power and worse fuel economy for your sedan and can lead to damaged fuel injectors.

Replacing fuel injectors isn’t cheap. Direct injection injectors are even more expensive because of the extremely high-pressure they use. Same thing for diesel fuel injectors; we’re talking mortgage payment-range to replace a set of diesel injectors.

A professional fuel system cleaning from Thompsons Auto Repair & Towing gets out the gum and varnish in the whole system, including the fuel injectors. Keep those injectors clean and they’ll last a long, long time.

Share

Posted in Fuel System | No Comments »