What is a “Tune-up?”

“I need a tune-up.” At least 5 times a week a customer will call and tell us that they need a “Tune-up.” I am aware the term tune-up is still used but today it isn’t really valid unless the customer is driving a 1965 Mustang.
You see, back in the day when cars and trucks had carburetors to manage the fuel, ignition points and condenser to handle the spark and an adjustable ignition distributor, a technician (called a mechanic back then) would actually take a screw driver and adjust the carburetor or “Tune” the carburetor to adjust the air/fuel mixture. He would also adjust the ignition timing using a timing light, use a feeler gauge and adjust the ignition points etc. This was almost always done after installing all new ignition components and sometimes without.
The “Tune-up” term has carried over to modern times and modern vehicles. Trouble is, there is nothing to tune. Today’s cars from approx 1982 on up don’t have some of those parts that I listed above. In the case of very modern cars, the only thing left to replace is the spark plugs. Modern cars have fuel injection, electronic spark control using a computer, various sensors that all talk to the computer system, ignition timing is now controlled by the PCM or powertrain control unit. All major systems and increasingly minor systems like the stereo and heater/ac are now all commanded by the computer. When a customer calls or comes into the shop in person, I always quiz them and I know sometimes it gets annoying for them but actually we are trying to access what it is their asking for. Some people think a tune-up is actually an oil and filter change.
When your car isn’t running correctly, or the SERVICE ENGINE SOON light or the CHECK ENGINE light is on, that is the vehicle’s way of telling you that an error code is stored in the PCM or computer. The auto technician now has to use a device called a scanner or a laptop computer with special software and interface with the PCM on the car and retrieve codes and read the datastream the computer is providing and interpret that data to make a conclusion which part or parts are causing the issues. This may require replacing a sensor or two, may need spark plugs, it may need other services. Point is, a “Tune-up” isn’t going to fix the issue. What you need is actually a Diagnostic service. Diagnostics will pinpoint the specific part or parts that are the cause of the problem. Times have changed and of course, vehicles are no exception. – Rob