MINNEAPOLIS (WCCO) — The value of getting a second opinion about expensive car repairs has been mentioned more than once in this space. One of my WCCO-TV coworkers recently shared the story of his $1300 repair that — because he didn’t just blindly accept that figure — turned out to be much, much less.
The story begins with a 10-year-old Nissan Maxima with a V6 Engine. It began running badly and sometimes just stopping, and the problem was traced to faulty ignition coils. Because this car is a 1996-and-later model, it has the federally mandated On Board Diagnostic system, Second Generation, or OBD-II.
This simply means that when major parts like the ignition coils malfunction, a code is stored in the engine management computer. This code can be read later with a scan tool, pictured above, which gives the mechanic (or do-it-yourselfer) a real good idea which parts to replace. Many car parts retailers will loan a scan tool to home mechanics with a deposit. Some will even bring a scan tool to your car in their parking lot & help you connect it.
Replacing the ignition coils on a Maxima V6 is no more difficult than replacing the spark plugs, but GETTING AT the plugs and coils on the back of the engine (three of the six cylinders are tucked up next to the firewall) requires removal of the plenum. The plenum is basically a two-piece air distribution box that bolts to the top of the intake manifold. There is also some other “stuff” to disconnect.
A mechanic friend of mine said coil replacement on this engine should take about two and a half hours … which means to me a home mechanic could do it in less than five hours. The Maxima owner didn’t want to tackle this job in his unheated garage, but his friend Carlos was up for the job. As long as the plenum was removed, it only made sense to put in new spark plugs along with the new coils, and this is where the first estimate got inflated. The shop listed the LABOR charge for removing the plenum TWICE: once for the plug replacement, and once for the coil replacement.
This picture of a coil-on-plug ignition coil shows the end that connects to the car’s 12-volt electrical system. The coil’s job is to change 12 volts into about 20,000 volts (some systems produce much greater voltage) to fire the spark plugs. This picture
shows the end of the coil that simply plugs onto the spark plug, so you can see how the labor to change the plug or coil SHOULD BE about the same as the labor to change both.
There was also a considerable mark-up on parts in the first shop’s estimate. My colleague got his coils for about $60 each at NAPA auto parts, and the plugs were about $3.50 each. The shop estimate had coils at $125 each, and the plugs were $9 each.
Carlos got $150 for labor, so the car got fixed — and it runs well — for less than $400. Compare that to the original $1,300 estimate, and you can see the value of getting a second (or third) opinion.