“Ask 12 mechanics what a tune up is and you will get 13 answers.”
Yep.
The term “tune-up” is neither precisely defined nor consistently used. Essentially, it means what the speaker thinks it means–and I venture that the majority of folks who say it have only a vague notion, at that. Nowadays, it’s pretty much an obsolete term, advertisements for tune-ups notwithstanding.
Before cars had electronic ignition and fuel injection, a fairly well-accepted concept of doing a tune-up was to replace the ignition points and condenser; set the dwell and ignition timing; replace the spark plugs; check the plug wires, distributor cap, and distributor rotor; replace the air and fuel filters; and adjust the carburetor mixture and idle. These items tended to wear out and/or get out of adjustment every 10-15,000 miles, so for most cars a tune-up was called for annually.
In those days, if a car was running poorly, getting a tune-up would improve, and often totally rectify, the performance 90+% percent of the time. Ignition timing routinely got out of whack as the points wore. Tune-ups, and sometimes just timing adjustments, were often done as repairs, not just maintenance.
Some shops would include more (oil change, battery service, etc.) in their tune-up, while some would include less (points, condenser, and plugs only). Some would offer a “major tune-up,” adding to the package above a carburetor overhaul, valve adjustment, and/or replacement of wires, cap, and rotor. And one would occasionally hear the term used for other services, such as a “transmission tune-up.” So even when it was a relevant term, it wasn’t a clear and consistent one. To add to the confusion, many shops refer to major service packages as, for example, a “60,000 mile tune-up.”
Nowadays, cars don’t have points and condensers. Their job is done by electronic ignition systems, with no routine parts replacement or timing adjustment necessary (on many modern cars, timing adjustment is not even possible). Distributorless ignition systems don’t have caps and rotors, and coil-on-plug systems don’t have plug wires. Mixture and idle are not adjustable on the latest cars, and very seldom need adjusting on the somewhat older ones. What’s left of the old tune-up is replacing the spark plugs and air and fuel filters.
Most cars call for plugs at 30,000 miles; if they use platinum plugs it’s 60,000 (or for some of the latest models, 100,000). Air filters are generally called for at 30,000; fuel filters at 30 or 60K.
Avertised “tune-ups” (usually for less than $100) typically include replacing the spark plugs and doing related checks and adjustments, if any are possible. With modern fuel injection and electronic control systems, if a car is running poorly, a traditional “tune-up” is unlikely to correct the condition, maybe helping about 30% of the time. It’s a maintenance procedure, not a repair.
I would suggest that the most helpful thing for the OP would be to have a thorough inspection of the car done, the type one should get before buying a used car. The idea is to learn what repairs are needed now or anticipated soon, and what maintenance is due (or past due or due soon). Then you’ll know what your car needs, and can decide what you might want to tackle yourself and what to have done by a pro.
