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What is a tune-up?
by Jim Addison
We find there are many different answers to questions about
the time-honored "tune-up." Answers depend on the car, the problem
with the car and the expectation(s) of the customer.
The dictionary defines tune-up as: an adjustment to ensure efficient functioning
(a motor). This original definition goes back to early days of motoring
when the engine had a spark coil for each cylinder. The current to these
coils had to be adjusted until they hummed “in tune.”
The points, condenser, coil and distributor system were first introduced
in l912 and used almost exclusively until the l970s. Because points would
get out of adjustment over time and spark plugs would wear out, a tune-up
usually consisted of replacing or adjusting the points, replacing or re-gapping
the spark plugs, adjusting the timing and usually replacing the filters.
Beginning in the mid-70s, car manufacturers were required to meet increasingly
strict emissions requirements and certify that their cars could meet these
standards for a certain period of time. The variance and wear in these
mechanical spark control systems proved unsatisfactory to meet the stricter
emissions guidelines.
In a way, we now have come full circle to direct ignition (no distributor
and a coil for each plug) on current model cars. There are no longer adjustments
to be made. One or more computers control spark and fuel in all modern
gasoline vehicles.
When a customers says, "I need to get my car tuned up," a good
repair facility begins a “What does this vehicle really need?”
interview by finding out what he/she is looking to correct or achieve.
First, the technician (or person writing the repair order) asks the customer's
opinion about why the car needs a “tune-up,” and the answers
usually fall into two categories.
One answer is that the vehicle isn’t running right; the other is
that the owner knows it needs some kind of periodic maintenance and “tune-up”
is their word for it.
Whichever category the customer’s concern falls into, further maintenance
questions need to be answered. When were the spark plugs replaced? When
was the oxygen sensor tested? When were the air and fuel filters changed?
Typically these items are recommended for replacement every 30,000 miles.
If the car has a running problem and a 30,000 mile service was done 15,000
miles ago, a “tune-up” isn’t going to help because the
plugs and filters aren’t due for replacement yet. In this case it’s
necessary to isolate the cause of the running problem through a series
of diagnostic tests. The source of the problem usually turns out to be
an ignition or fuel injection sensor or component.
If the customer’s concern is maintenance, the facility will usually
try to discover which maintenance services have been done, then suggest
a plan for bringing the car up to date and recommend following the factory
recommended maintenance schedule in the future. Most manufacturers recommend
major services at 30,000, 60,000, 90,000, etc. miles, with minor services
usually done at 7,500 or 10,000-mile intervals.
Major services typically consist of replacement of spark plugs and filters;
fluid changes including engine, transmission, coolant and brake fluid;
inspection and testing of the emission systems; sometimes replacement
of the oxygen sensor and a very comprehensive inspection of the entire
vehicle--including brakes, exhaust, suspension, drive shaft, boots and
electrical components. It often includes a timing belt at 60,000-mile
intervals.
Minor services consist of a comprehensive inspection, oil change and such
adjustments as belts and rotating tires. An oil change is recommended
in the interval between minor services. Your vehicle’s maintenance
recommendations are in your owner’s manual.
So “Tune-up” has become an outdated term. It’s best
to know and follow your car's maintenance recommendations and then communicate
clearly with your auto repair shop regarding any additional problems.
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