Car Talk: The Secrets of Auto Repair Shops

Plus, tips on working with a mechanic
Author Les Jackson knows cars: He has restored and worked on hundreds of them, including this 1955 Thunderbird. Photo Illustration by Jesse Lenz
Author Les Jackson knows cars: He has restored and worked on hundreds of them, including this 1955 Thunderbird. Photo Illustration by Jesse Lenz

I bought my first car at age 14. By the time I turned 15 and
got a learner’s permit, we–the car and I–had accumulated some 200 miles up
and down my parents’ driveway. I also had accumulated a decent box of
tools and was learning how everything on the car worked.

I was, and still am, a gearhead–obsessed with automobiles. In
the past 50 years, I’ve worked on hundreds of cars. I’ve restored a dozen
British and American classics, built engines and transmissions, and taught
automotive theory.

And I’ve seen the industry change. Gone, for the most part, are
the days of the cluttered, dirty garage with old parts on the floor, dim
lighting, and mechanics who wipe their hands with oil-soaked rags. Those
mechanics have been replaced by a new breed trained in electrical theory
and mechanical and computer systems. Now called “technicians,” they
generally work in clean, well-lit shops.

The National Institute for Automotive Service Excellence gives
exams in more than 40 specialties, and good mechanics aim to be
ASE-certified in a number of automotive systems. ASE master certification
is considered the gold standard.

Most auto technicians are honest and hard-working. Some aren’t.
The world of auto repair is still susceptible to incompetence and scams.
The volume of complaints to federal, state, and consumer-protection
organizations suggests that unnecessary or faulty repairs cost consumers
millions of dollars annually. Finding a shop you can trust–see our list of
recommended garages on page 135–is the best way to avoid wasting money on
a car. What follows is my advice on preventing bad

Oil Change Every 3,000 Miles?

Many people believe they should change their car’s oil every
3,000 miles. In my opinion, it’s one of the biggest myths in the
auto-repair industry.

The last time cars needed to have such frequent oil changes was
in the early 1970s, before clean fuels, computer controls, and more
sophisticated engines and oil chemistry.

Don’t take my word for it–trust the engineers who designed your
car. They know more than anyone else who services it, and they wrote into
your owner’s manual the actual oil-change requirements. Most cars can
safely run 7,000 miles or more before an oil change; some makes and models
can go up to 15,000. Many vehicles have sensors and software that will
monitor your driving conditions, such as long distances versus stop-and-go
traffic, and tell you when to change your oil.

In an effort to reduce pollution from waste oil, the state of
California has created a website ( that gives
manufacturers’ recommended oil-change intervals.

Well over 30 brands of oil additives are for sale in stores and
on the Internet. They claim to give a car greater fuel economy, longer
engine life, more power, lower emissions, and smoother operation. Don’t
waste your money. No manufacturer recommends additives, and using them can
void the warranty. Carmakers have spent billions on sophisticated fuel
delivery and other technologies to achieve reliability and

More Services You May Not Need

There are other high-profit services most vehicles don’t
require during their lifetime. Here’s a look at some common

Engine Flush

The sell: Engines develop sludge, and a flush
removes that sludge.

The fact: I’ve heard people in the
auto-service industry call this a “profit center,” an easy-to-sell but
unnecessary procedure. An engine flush can actually harm engine

Injector Cleaning

The sell: Fuel injectors become dirty and
clogged and rob the engine of power and fuel economy, so there are
services to solve the “problem,” from putting additives in the fuel tank
to flushing the injector assembly.

The fact: Most cars never have problems with
fuel injectors. Besides, the only way injectors can be cleaned properly is
by removal and disassembly, which is hardly ever done. Your engine’s
computer will tell you if there’s a fuel-delivery problem; otherwise, you
can leave things alone. If the computer does indicate a problem, have the
fuel filter checked. Clogged fuel filters cause most problems.

Head-Gasket Replacement

The sell: Oil or coolant leakage from the top
of the engine may indicate that the head gasket is failing, so an
expensive replacement is needed.

The fact: Head gaskets seldom fail; if they
do, the engine will run poorly and blow smoke. All engine gaskets will
begin to seep oil after a certain mileage and amount of time, so if the
engine is running fine and you’re not having to top off the oil
frequently, there’s likely nothing to worry about.

Timing-Belt Replacement

The sell: Many shops suggest replacing a
timing belt before it’s necessary. They may claim that the belt never
lasts that long or that it has stretched and is altering the engine timing
or that it’s about to fail and destroy your engine.

The fact: Trust your owner’s manual on when
the timing belt should be replaced; most manufacturers suggest it at
intervals of 60,000 miles or more. There’s no way for a mechanic to see
that a belt is failing without removing some components–it can run
silently until it breaks. While it’s true that in older cars a broken
timing belt can harm the valves, vehicles made in the past decade or so
are designed not to experience engine damage if a timing belt

Emission-System Repairs

The sell: Your car failed emissions
inspection; the shop suggests a system overhaul.

The fact: The system may need repair, but many
owners pay for oxygen sensors, catalytic converters, and other
emission-system components when they shouldn’t. Vehicles made since 1995
carry federally mandated warranties that cover those components for eight
years or 80,000 miles. Reputable shops will tell you about this and refer
you to a dealership if they can’t get the manufacturer to authorize
repairs on-site.

Scheduled-Maintenance Add-Ons

The sell: You’ve brought your car in for its
scheduled maintenance–say, at 30,000 miles–and the shop recommends other
services, claiming that the scheduled-maintenance checklist is only the
minimum requirements.

The fact: Those scheduled-maintenance
intervals are written into the manual to address known component lifetime
issues and to allow technicians to monitor other components that might
exhibit premature wear. A lot of shops add unnecessary services to those
listed in the scheduled maintenance. When taking your vehicle in, agree
only to those items listed unless there’s an obvious problem.

Dealer or Independent Shop?

Surveys show that most consumers prefer to take their vehicles
to independent garages for repairs. Cost and convenience are the most
frequent reasons why.

That said, it’s risky to have your new, in-warranty vehicle
serviced at an independent shop for anything other than tires, batteries,
and wiper blades. If an independent shop services a major component of
your vehicle and something goes wrong, the manufacturer may not have to
honor the warranty. I would suggest not taking your vehicle to an
independent shop for major repairs until your car is out of

Many independents use generic or rebuilt parts that aren’t made
by the same company that made the original parts for your car. These are
generally cheaper and sometimes justified, but major components–especially
safety or drive-train equipment–should always be OEM, or
original-equipment manufacturer. Rebuilt or generic components might use
structurally weak materials that can fail or wear out quickly or, in the
case of safety equipment, fail to operate.

When it comes to major repairs on a newer vehicle–such as
engine or transmission rebuilding or a fuel-injection system–it’s
generally better to take the car to a dealership. It will have the most
up-to-date diagnostic systems, tools, and technical training, and a larger
percentage of dealership technicians are ASE-certified. Although its parts
and labor rates might be higher, there’s a greater likelihood that the
problem will be repaired without subsequent issues.

Dealer warranties on such work are typically better because of
franchise obligations that the dealers must honor. Dealers may also
participate in manufacturers’ unofficial “silent warranties,” under which
certain components with higher failure rates are repaired at no

Skip the Extended Warranty

Where you bring your car for repairs may be dictated by whether
you bought an extended warranty. Extended warranties promise to protect
against unexpected, costly repairs.

While an extended warranty may sound good, I’d suggest not
buying one until you understand the terms of the contract and who is
responsible for providing repairs.

An extended warranty isn’t a warranty–it’s a service contract.
The cost averages about $1,000 but can be more than $3,000 depending on
the company and the vehicle’s model, age, and mileage. Extended warranties
commonly have deductibles and limited payments that are keyed to the value
of the vehicle.

While some extended warranties are offered by dealers or
manufacturers, others are sold through independent companies. Many outside
service-policy companies have gone out of business, leaving behind angry

“An extended warranty is only worth considering if the vehicle
you’re buying has a below-average reliability rating,” says David
Champion, director of auto testing at Consumer Reports.
“Otherwise, it’s not cost-effective. But if you do buy one, make sure it’s
backed by the manufacturer. Better yet, open a savings account and deposit
the money you would have spent on a contract every month. It will
accumulate to pay for future repairs or a down payment on a new

How to Find a Good Shop

If you’re looking for a good repair shop, ask friends and
neighbors for referrals. You’ll also find a list of reader-recommended
garages beginning on the next page.

When you visit a shop for the first time, look around. Clutter,
spilled fluids, disorganization, dirty restrooms, and shabby equipment
generally indicate a poorly managed business. It’s a good sign if a shop’s
labor rates are clearly posted.

Bear in mind that a shop can have the familiar blue ASE sign in
the window, but all that means is that at least one technician has passed
exams. Ask how many technicians are certified and in which areas. Separate
certifications are offered for electrical systems, engines, transmissions,
drive trains, bodywork, suspension systems, and more.

If possible, talk with the technician who would be doing the
work on your vehicle to assure yourself that he or she is experienced
enough to solve your problem.

When you bring in your car for repair, the shop should present
paperwork that spells out the limit of the shop’s liability, the
parts/labor warranty, and what remedies you’d have if something went
wrong. That document is a contract, so it makes sense to take your time
and read it.


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