Automotive FAQ

Automotive FAQ

Here are a number of questions we receive frequently enough to know you might want to hear the answers:

Q: Do I really have to change my oil every 3000 miles?
A: The 3,000 mile oil change has fallen out of favor with many folks. All sorts of people from environmentalists to politicians espouse the benefits of leaving the oil in the car for 5K to 10K miles. There’s even a new law that prohibit mechanics from recommending any interval other than that in the service manual. Will oil maintain its viscosity for 5,000 miles? Probably, unless the engine is worn. However, oil consumption at the rate of 1 quart per 500 miles is considered normal. It’s not, but that’s what many manufacturers say. A more realistic “normal” is about 1 quart per 1,500 miles.

If oil consumption is 1qt/1500mi, the car will likely make it 3,000 miles without the sump running dry. If you wait 5,000 miles, the engine will run out of oil before you change the oil, ruining the engine. The astute among you may be wondering why not just add oil between changes, and yes, that’s the way it’s supposed to work. Here’s the thing… y’all ain’t checking and topping your oil. We see new cars coming in with no oil all the time. So, should you change your oil every 3,000 miles? Well, if you are in the habit of checking and filling your oil when you get gas, then go ahead and wait 5K. If not, shoot for 3K and try not to be late.


Q: How long can I drive with my oil light on?
A: The Oil Pressure Icon (the one that looks like a Genie’s Lamp) is a PRESSURE INDICATOR, NOT A LEVEL INDICATOR. When that light comes on, you have no oil circulating through the engine. Operating the engine in this condition means instant death for your engine. If you see this light, stop the engine immediately and investigate. Remember, when the genie lamp comes on, you’re out of wishes!

Q: Should I use synthetic oil in my engine?
A: Synthetic oil is superior to conventional oil, but the average driver may never realize the benefits. Consumer marketing has generated much interest in synthetics, but it is generally understood that synthetic oils are designed primarily for high performance and heavy-duty applications.

The cost of synthetic oils can run two to three times that of conventional oils. The manufacturers of synthetics tout that the increased cost of the synthetics are offset by the reduced frequency of the change interval, given that the synthetics are less prone to breakdown due to heat and friction. In a new engine this may hold some truth, but breakdown of the oil is not the only consideration. Oil consumption and contamination are critical considerations in oil maintenance, as discussed above, and synthetic oils are just as susceptible to these factors as conventional oils. So, if you use synthetic oil, it still needs to be changed every 3-5k miles, and topped between changes, on most engines after 60k miles on the odometer.

For the average driver, conventional oil with the proper API/IL SAC ratings will not break down and fully meets or exceeds the requirements of the engine. We service many engines that have run on conventional oil for over 200k miles, illustrating that regular changing and topping of the oil is the best recipe for success, regardless of the type of oil used.

Of course, if the manufacturer specifies synthetic oil it should be used to protect the warranty.

Q: Why do my brakes vibrate and my steering wheel shimmy?
A: Vibration when braking is caused by brake rotor (disc) thickness variation (warpage, parallelism). We will not focus so much on the technical aspects of warpage, more on understanding how to prevent it.

Brakes operate by friction, friction creates heat, heat causes rotor warpage. Any time you are braking the vehicle, you are introducing heat into the rotors. So, logically, the less you brake, the better, right? Well, maybe this is easier said than done, so here is what you can do:

1. Use the transmission to engine brake on grades.
2. Modulate braking on grades, meaning brake, release, brake, release, which allows the rotors to dissipate heat. Don’t give your passengers whiplash in the process, though.
3. Following heavy braking, if the vehicle is at a stop, do not stand heavily on the brakes, and do not set the emergency brake with excessive force.

Q: How often should I align my vehicle?
A: The shops that exclusively do tires and alignments may tell you to do one on a specific schedule. However, the fact is you can do an alignment one day, and the next day hit a pothole and knock it out again. Our opinion is that an alignment should be done when there are symptoms of a need for an alignment, or preventatively when tires are replaced, specifically as insurance for the tires. The most common symptoms of a needed alignment are: the vehicle pulls on a smooth, flat surface; a steering wheel that is not centered when driving straight; and erratic tire wear. As a driver, you can pay attention for the first two symptoms, and your mechanic can pay attention to the tire wear. Unfortunately, this is not guaranteed to prevent problems, but is the most realistic approach.

Q: My steering wheel shimmies at freeway speeds, doesn’t this indicate an alignment problem?
A: Actually, this usually indicates a wheel is out of balance. On this subject, if you pay attention to dealer services or ‘free tire rotation’ programs, you will notice that they never include a tire balance. So, make sure your tires are balanced whenever they are rotated. The one exception we make here is on the newer vehicles that have gone to a 5k oil/brake/tire schedule, which is the subject of another Q&A.

Q: How does a clutch work?
A: The mechanical clutch is comprised of three basic parts (not including the method of actuation). Refer to the illustration below:

The Pressure Plate attaches to the Flywheel (not pictured) which is a large metal disc attached to the crankshaft of the engine. The flywheel is the work output of the engine. The Friction Disc (driven plate in the picture) is sandwiched between the pressure plate and the flywheel. The transmission input shaft inserts into the center of the friction disc; the splined shaft is the work input of the transmission. When the clutch pedal is released, the pressure plate is forced against the friction disc, locking the flywheel to the input shaft of the transmission, transferring the work from the engine, to the transmission. When the clutch pedal is depressed by the operator, the release fork operates as a lever, forcing the Throwout Bearing against the pressure plate, which causes the pressure plate to draw back from the Friction Disc. This unlocks the Flywheel from the Transmission Input Shaft, preventing the work of the engine from transferring to the transmission.

Q: How should I service my car?
A: This is a very complicated question if all nuances are to be considered. There are three basic considerations in answering the question:

1. With a new car, to protect the warranty, you can take a literal interpretation of the maintenance schedule and proceed accordingly. This has many pitfalls, specifically in context of the fact that the OEMs are whittling away at the ‘to do’ list, turning the traditional service items into inspection items. This is deliberately done to artificially lower the perceived lifetime maintenance costs. Our recommendation is ‘to do’ the traditional service items, as we will discuss later.

2. Late models and special models:

Late models; the Toyota Prius was the first to go to the 5k interval for >Oil Change, Tire Rotation, Brake Inspection<. For reasons that are numerous and complicated, we are toeing the line here until 60k on the odometer, or until the vehicle is out of the powertrain or hybrid warranty. It now seems that many late model vehicles are going to this schedule.

Special models; 2005 and newer Hondas are special considerations, in that they have a logic-driven Maintenance Minder system. Honda owners should inquire specifically, but our recommendation is to service the vehicle in the traditional fashion, or do the Maintenance Minder indicated, whichever comes first. This is just one example of a special model consideration.
3. The traditional Service Schedule. This applies to nearly all vehicles we work on, and should be used as a basic outline for a common-sense approach to maintaining your vehicle:

1. Oil Changes Every 3000 Miles
2. Brake Inspection/Tire Rotation and Balance every 7500 miles
3. Major Service every 15k Miles, consisting of:
*Full Vehicle Inspection
*Tire Rotation and Balance
*Air Filter
*Oil Change
*Automatic Transmission D&F
4. Major Service every 30k Miles, consisting of:
*15k Service items, plus-
*Cooling System Service
*Brake Fluid Flush
*Clutch Fluid Flush (if equipped)
*Transmission Oil Change (manual or automatic)
*Driveline oils (RWD or 4WD vehicles)
*Standard Spark Plugs
*Cabin Filter (if equipped)
5. Special Considerations too vehicle-specific to generalize, so you have to ask about:
*Platinum or Iridium Spark Plugs
*Valve Adjustments
*Fuel Filters
*Spark Plug Wires, Distributor Cap and Rotor
*Timing Belt
6. Finally, don’t forget to refer to notes from prior repair orders, especially brake and tire information that can supersede the general schedule.

Q: What kind of vehicle should I buy?
A: Obviously, the platform you select must fit your needs. However, at Art’s Automotive, we all agree that Toyota and Honda are engineered the best, period. The shop is split evenly down the middle as to which is preferred of the two, but you really can’t go wrong with either. So, find the Toyota or Honda that best suits you!

But what about a Subaru? Or how about those Mazda 3’s and 6’s? Well, Subarus are great when they aren’t broken, and for a long time they had the niche market cornered with the AWD wagon. But now everyone has something that can fit the bill, and the fact is if you own a Subaru you can expect more problems, more often. Maybe we’ll dedicate a special section to their pattern problems later… And as for the new Mazda products, you may be shocked to learn that they are actually Fords, inside and out.And, you guessed it, just like most domestic vehicles, they break in unpredictable ways, often at low mileages. Yes, we know that Consumer Reports raved about them, but, much like the oil change study, they are looking at these cars at way too low mileages to have an opinion on long-term reliability.

Q: My Check Engine Light just came on, what do I do?
A: First off, you should relax. If the Check Engine Light is not flashing, and the engine appears to operate normally, it is not considered urgent. The Check Engine Light (‘Service Engine Soon’ light on Nissan products) is turned on by the Engine Control Unit when it determines there is a problem with a sensor or system it monitors. It usually means a repair is required, but the system is redundant enough to allow for safe operation until it is convenient to have the problem diagnosed properly. It should be specified, though, that if the light is flashing, the vehicle should not be driven, should be towed to a repair facility. Before scheduling a diagnosis, be sure to check your gas cap; a loose or missing cap will turn the light on. It is also recommended to check your engine oil and coolant, and to monitor the other gauges, but this is true any time there is a question with the engine.

Q. My brakes squeak but my mechanic says they are fine. How is this possible?
A: Brakes do what they do through friction. Most brake noise complaints are caused by disc brakes, so that will be the focus here.

The brake caliper squeezes the brake pads, causing the brake pads to clamp down on the brake discs (AKA Rotor); while the vehicle is in motion with the brakes applied, the pads are rubbing with great force on the discs. The rubbing creates vibration, the vibration sets up a harmonic in the hardware (brake disc, steering knuckle, etc.), and the result is audible noise. Think of a wet finger rubbing the rim of a wine glass, creating an audible tone; this is very similar to the phenomenon of brake noise.

Now that we know why brakes squeak, what can we do to make them quiet? Obviously, we try to reduce and absorb vibration.

Of all the causes of brake noise, the choice of brake pad is the most common. Cheap aftermarket brake pads are almost guaranteed to squeak, while Original Equipment Manufacturer (OEM) pads are unlikely to squeak. This is because there are multiple objectives when making a brake pad: reduced brake noise, reduced brake dust, resistance to brake fade, increased pad life, and increased disc/rotor life (to name the most common). Unfortunately, most of these objectives have an inverse relationship. Forone brake pad to do it all, it must be made of many different materials, and shaped differently from one application to the next. The OEMs put considerable Research and Development into each and every brake pad they make, and so nearly every automobile has a unique pad designed specifically for it. The aftermarket manufacturers simply do not have the resources to compete with the OEMs, thus the tendency for their pads to squeak (among other adverse performance characteristics).

The next important consideration is the brake disc surface. Any glazing, scoring or otherwise uneven disc surface exacerbates the tendency for vibration to occur, which of course causes squeaks. Machining (resurfacing) the brake discs gives the pads a smooth, flat surface to mate to; this reduces vibration, and eliminates uneven or deficient braking that can occur while a new pad is bedding into an old disc surface.

Another important detail is brake shims. Vehicles come with shims attached to the back of the pads. The shims are thin metal wafers, and their job is to absorb or insulate the vibration so that it does not transmit to the hardware, where the audible noise occurs. The OEM shims often will not fit aftermarket pads, or will wear out with usage, so often they are discarded by less detail-oriented mechanics . Unfortunately, new brake pads, OEM or otherwise, often do not come with shims, so it is common to see brake pads with no shims.

The final consideration is preparation of materials. There are specialty lubricants (moly paste usually) that are designed to be placed on the back of the pads and shims, and between the contact points where the pads are captive in the caliper brackets. The moly paste has considerable ‘body’, and so is a major player in absorbing the vibration. Many hasty mechanics fail to use the paste, so it is a good barometer for attention to detail when evaluating a mechanic’s work ethic.

So to recap, the recipe for a smooth, quiet brake job is to use OEM pads, machine the rotors, install the shims and apply moly paste to the back, top and bottom of the pads.

Two final notes: One, just because brakes are noisy does not mean repairs are required. If your mechanic inspects the brakes and says they are OK, it is entirely discretionary as to whether anything should be done from there. And two, it should be pointed out that there are other steps to performing a brake job, but that is a separate discussion.