Tech Tips

One of the most common sources of confusion for car owners is the difference between balance and alignment. Wheel balance is most important on the front wheels. It doesn't affect tire wear much unless it's way off. When a car's steering wheel shimmies at freeway speeds, almost certainly your front wheels are out of balance, your front tires are not round, or both.

Alignment almost never causes a shimmy. Alignment is, however, directly connected with tire wear and is one of the reasons a car may pull to one side or the other when going down the road. Knowing the difference between balance and alignment can save you a lot of grief, but the safest thing to do when you take your car to the shop is to explain the symptoms you have experienced instead of asking either to have your front end aligned or to have your front wheels balanced. Your shop may not be sympathetic when you tell them "I had you align my car last week and it still shimmies as much as ever."

One of the biggest enemies of your car's brakes is heat. Think about the fact that the same amount of work is performed to slow your car down as is performed to speed it up. That means that you produce a lot of heat going down hills. Most engines have coolant, a water pump, and a radiator to dissipate the heat of making the car go. The brake system has to do the same job with fewer tools.

The main way to get rid of heat is for the surface of the disks to absorb it and spread it out through the metal body of the disk and from there to the air rushing by the disk. Normally this system works fine. If the brakes are applied steadily over a period of time, though, the disk has no chance to get rid of the heat. If the heat builds up long enough, the brakes get hot enough to be damaged and then rendered ineffective. "Brake fade" means that the brake pedal feels fine but there is no longer adequate friction between the pad and disk. If the brake fluid reaches the boiling point, some of the fluid or contaminants (like water) mixed with the fluid boil and turn to gas. Unlike liquids, gases compress easily. The formerly firm brake pedal gets mushy or goes to the floor.

To avoid overheating the brakes, the driver should make sure to have the engine do some of the braking when going down long hills. That means that the transmission should be shifted into a gear that lets you take your foot off the brake pedal a fair amount of the time, thereby giving the brakes a chance to cool.

Another precaution you can take to prevent brake problems connected with overheating is to keep your brake fluid clean and pure. Your shop can help you do this by flushing the brake lines or by periodically replacing some or all of the brake fluid.

Anti-lock brakes are part of almost every newer car. They give the driver the ability to stop as quickly as possible without risking a spinout. The system includes sensors at the wheels, a pump and valving to control the wheel brakes individually, and a control unit to check the speed of each wheel and release the brakes on any wheel that threatens to come to a stop (lock up).

If the computer senses that something's wrong with the system, it shuts the ABS system down and turns on a light. The power of the system explains both what it can do right and why it needs to be shut down if it's malfunctioning. While you can almost always keep driving your car in the short run, the ABS light being on tells you that the ABS system is disabled. Sometimes the ABS light will go out after stopping the car and restarting it, but chances are good that it will come on again.

The marvels of modern technology have allowed engineers to use the ABS components more every year—for example, to avoid spinning out on turns even when you’re not braking. In the meantime, older cars with the basic ABS system are already an improvement over cars with no ABS. Your car will stop straight even if you need to slam on the brakes.

Timing belts connect the crankshaft (pistons) to the camshaft (valves). For the engine to work correctly, the valves must open and close at the right time. The timing belt has notches that fit into gears on the two shafts and keep them in time (synchronized with each other).

When the timing belt breaks on any car, the car will stop running. On many modern cars (for example all Volvos after 1995 and some before), the engine will be rendered useless if the belt breaks or if a supporting bearing or the water pump goes bad. Replacement intervals on these cars are critical. Time is important as well as mileage. The rule of thumb we use is to replace the timing belt at the manufacturer's suggested mileage or after 10 years, whichever comes first.

We suggest that you replace all the components connected with the timing belt system while you're at it-you don't need to have a component you neglected to replace fail before the next timing belt interval. At the very least, you'll have to pay the labor to do the job all over again. At the worst, you might have to replace the motor.

At the Model Garage, we'll try to remind you to replace the timing belt early enough to be safe. In the mean time, please call us if you need more information or advice about your particular car

1. Tires connect you to the road. Every car we service gets a tire check--we measure the tread depth of all 4 tires and adjust the tire pressures to factory specifications. Minimum tread depth, in California, is 1/32", but it's better to have more tread depth on slippery surfaces. Fall and winter are two seasons that especially call for good tires. If your car needs a tire rotation, we will inform you; with your approval, we'll rotate the tires.

2. Wiper blades have been baking in the sun all summer. Now that they're needed in a big way, it's time to evaluate them and replace them if necessary. We stock wiper blades for most of the cars we service, and installation is labor-free.

3. Watch out for leaves. Not only do they make any road surface more slippery and hide road hazards, they can clog the car's natural drainage. You can help your car out by removing leaves that have built up below the windshield and around the trunk when you fill up with gas.

4. First Rain. The first rain after a dry spell lifts accumulated oil that is lighter than water and that mixes with the rain water to create a very slippery surface (more slippery than just a wet surface). Stop and start carefully after a first rain to avoid losing control of your car. Now is a good time to repair your ABS system if you've been putting it off, since the chances of spinning out when braking are significantly higher.

5. Ice and frost, while not common in our immediate area, are something to watch out for as soon as you leave here. Black ice, in particular, is hard to see and is potentially very dangerous. Overpasses and bridges are often home to black ice, so slow down for them. If you can plan your trip to avoid early morning and night driving, you can minimize the danger of black ice.

6. Sun glasses and a working sun visor help with early morning and late afternoon glare from a sun that sits on the horizon.

7. Regular service. When you bring your car in for service, we will inspect it thoroughly. Since we are trained professionals, we may see things that you don't. Which means you get the opportunity to have us take care of them.

The tips we have listed should help you have a safer, more trouble-free fall and winter. Happy Motoring from the Model Garage.

Several car manufacturers recommend using gasoline which meets additive standards called "Top Tier". The reason for this is that many gasolines on the market do not contain enough detergent additives to keep your engine clean and running well. One of the byproducts of incompletely burned gas is carbon which can coat the inside of your engine's intake system, valves and injectors.

The detergents in good quality gasoline help to clean these deposits off. If it is not cleaned off this carbon can absorb the gas as it is injected into the engine and create a poor mixture of air to fuel. Carbon can also keep valves from closing properly or clog the fuel injectors. The most common and hardest to detect is coating of intake parts resulting in a poor mixture. This can result in poor gas mileage, low or rough engine idle or intermittent stalling, but without taking the engine apart to see (and clean) these deposits it can be very difficult to know why it is happening.

Therefore we recommend using good quality gasoline (of whichever octane the manufacturer requires) in all cars. We may also recommend to you that we add extra detergent additive to your car's gas tank if we think there is a potential problem.

Prius seems to be particularly sensitive to bad gas. While there are many causes for poor gas mileage (most important being tires and tire inflation) we think gas type might be a big contributor to disappointing mileage in these cars. It also seems to be implicated in several cases of intermittent engine misfires. In serious cases codes are set in the computer and the check engine light can come on.

Most of the major oil company gasoline meets "Top Tier" standards along with some obscure brands, but some gasolines that are in common use in this area are not on that list. We would recommend you avoid these. The list of brands that qualify can be found at TOP TIER Detergent Gasoline Retailers on the Internet.

When we work on your car, the most common reasons for service and/or repair are 1) Recommended maintenance and 2) Replacement of broken parts. There is another category that you and the Model Garage should consider, and that is replacement of parts due to age. Many of our customers have cars that they are happy with and that they would like to keep for at least several years. For those owners, we've tried to offer a few ideas.

Regular Oil Service: It's a good idea to perform an oil change service at least every 6-8 months. Changing the oil is only part of the benefit--we road test your car, adjust tire pressures to manufacturers' specifications, note tire tread depth, check fluid levels, and look the car over with a trained eye. If we see something amiss, we'll bring it to your attention.

Radiators: Failed radiators can cause serious problems in both Volvos and the Toyota family of cars. Replacing the radiator (if it's original) after 10-12 years would not be excessive.

Coolant Hoses: Volvos and Toyotas come with good quality hoses, but after 10-15 years, you should consider replacing them. The expense of replacing them is significantly less than replacing the car or the car's engine if it overheats. It's all part of providing you with safe, reliable transportation.

Transmission Oil Change: On cars we maintain, we check the transmission oil quality periodically. If it's dirty, draining and refilling the transmission oil is inexpensive preventive maintenance. The exceptions to this rule are some very late model cars. In days gone by, we used to change the transmission oil every 15-20,000 miles. Manufacturers have cut back on transmission oil changes, but we'll help you decide if they make sense for your car.

Timing Belts: The #1 preventable cause of engine failure on interference fit engines (engines on which the pistons will hit and damage the valves if the timing belt breaks) is a broken timing belt. Although we generally use manufacturers' mileage recommendations to determine timing belt intervals, there are exceptions--feel free to ask us what our experience tells us about your car. We recommend replacing the timing belt after 10 years, regardless of mileage, on most cars.

Batteries: If your car battery is over 5 years old, it's a candidate for replacement. The inconvenience of a dead battery is worse than losing out on a little battery life. When we service your car, we'll check your battery, but we may need your help to determine the battery's age. Please let us know if your battery is over 5 years old.

Remote Batteries: If you're not sure when the batteries in your remote were last replaced, it may be time. If you bring all your remotes with you when you come in for service, we'll gladly replace the batteries for the price of the batteries.

Assessing the value of your car can be done several different ways with correspondingly different conclusions. The most common way of putting value on a car is to determine what it would sell for. Seems logical, but if you've ever sold a car involuntarily to an insurance company, you know that your car is worth more money to you than you receive. You would likely have to spend quite a bit extra to replace it.

We suggest you use a few criteria to evaluate a car's value to you. Start with these questions:

1. Do you like the car? If you hate your car, life's too short to keep it. If you love your car, on the other hand, that's worth a lot.

2. Does your car fit your needs? Not exactly the same question. If you are totally dependent on your car, the standards of reliability are higher than if you drive locally and have some flexibility in your schedule; you may need to have more invested in the purchase price of the car. If the car is for your child to use, gas mileage may be less important than safety. If your back feels good in your car's driver's seat, that's worth a lot. If you need to transport a sports team to games, the number of seats is probably more important than other factors, although you still need to make it to the event safely with your players. If you drive to BART and park, then drive home, you don't want to have too much invested in your car. It still needs to start, and it needs to have a hood that doesn't open easily so that your battery won't be stolen.

3. Do you need to wait a year or more to replace your car? Then in the meantime, the car needs to work for you.

4. Do you have the feeling that at any time your car may let you down. Time for a new feeling with a different car or for an investment in reliability beyond just fixing what's broken.

5. Seat heaters double the value of your car.

Feel free to call to discuss the big picture with us. Our goal is to help make your transportation situation as pleasant as possible and to provide you and your family with safe, reliable transportation.

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