When I was about 18 years old, I bought a Corvette.  And it was the worst financial mistake of my life.  Just kidding.  Well, kind of.  Anyway, one of the good things that came out of owning that car is that I learned a lot about fixing cars.  One of the other good things I learned is that you can’t always trust your auto mechanic.  Even if it really, really seems like he knows what he’s doing.  And probably especially if you’re a girl and your mechanic is a guy.  But if you’re a guy and you’re reading this, keep reading, because you may learn something, too.

My Bad Decision

First, let’s get this out of the way.  This was my Corvette.  Ain’t she pretty?

CheckPT 2

Please excuse the poor quality of the photo.  This was taken back in about 1998, when digital cameras were a joke compared to what they are today.

Don’t ask me why, exactly, but I fell in love with Corvettes when I was a little kid, probably around 7 years old.  I regularly gawked at them on the freeway, and would stop on the street to stare at them.  There was a Corvette in the parking structure of my dad’s condo complex, and every time I walked past it, I’d trace the letters C-o-r-v-e-t-t-e on the back of the car.  I knew nothing about cars, but I knew that I loved Corvettes.

When I turned 18, my stepdad had a friend who was selling his Corvette.  My stepdad figured he would cure me of Corvettes forever by having me drive the car around with a For Sale sign in the back.  He thought the ride would be so uncomfortable that I’d be thrilled to get rid of it at the end of the week.  It backfired.  I bought the car myself.  It’s the one in the photo.

It had a ton of issues.  Not all at once, or I might have figured out sooner that I should have dumped the thing, but it ended up costing me about $500 per month on average.  I drove it every day (well, other than the days it was on a tow truck) for 16 months, and it cost me $8,000 in repairs.  Ouch.  And that’s not even counting the work that I did to it myself.  My stepdad and I were regulars at the Kragen Auto Parts.  We literally knew most of the employees, and they all recognized us on sight.

Learning from My Stepdad

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My old Chilton’s manual! I found this in the garage a couple of weekends ago.

My stepdad taught me a lot about fixing cars.  He wasn’t part of every car repair, not even close (he had things to do, too), but he got me rolling, and he was always the first person I’d ask if I needed tech support.  On his advice, I bought a Chilton’s manual, and that helped a lot.  I also borrowed his tools constantly.  Fortunately for him, I’m a little OCD, so I always left his toolbox more organized than it was when I first found it.  For Christmas that year, my dad got me my own starter set of tools.  🙂

My stepdad taught me a lot of things, like “NEVER read the instructions,” except when you’re installing headlights for the first time, and then ALWAYS READ THE INSTRUCTIONS before you go touching the bulb with your bare hands and ruining it.  (The oils from your fingers stay on the bulb, and when the bulb heats up, it can cause it to shatter.)  I pretty much always read the instructions after that.

Another thing he taught me was the regular maintenance intervals for most cars.  This was back in the day when pretty much everything was standardized.  Just about all cars took conventional 10w30 oil, at least in our Southern California climate, and oil needed to be changed about every 3,000 miles.  Spark plugs and wires needed to be changed about every 30,000 miles.  Belts and hoses needed to be checked or replaced every 60,000 miles.  Front brake pads needed replacement about every 30,000 miles, rear brakes about every 60,000 miles.  Simple.

Lots of people I know picked up weird car information from their parents and grandparents.  There was one girl who kept telling me that her grandpa told her to always turn her A/C off when she shut off the car.  She said that trying to start the car with the A/C on would break…something.  She didn’t know what.  Yeah, that’s not a thing.  And I’m sure everyone knows at least one person who thinks that putting super premium gas in their piece o’ crap car will make it run better / go faster / get better gas mileage.  Nope, nope, and nope.

But those are just the urban legends.  What about the lines of bull that your mechanic feeds you?  Here are a few tips to make sure you don’t get taken for a ride.

Don’t Listen to Your Auto Mechanic

Not all auto mechanics are bad.  Some of them are actually very good.  But if you think your mechanic is one of the good ones, and they feed you one of these lines, you might want to reconsider how good your mechanic actually is.

Change Your Oil Every 3,000 Miles

If your car was built in the mid-1990s or earlier and runs on conventional oil, then you might want to change your oil roughly every 3,000 miles.  But if your car was built any time after that, check your manual before you blindly follow this advice.  My 2009 Toyota calls for an oil change every 5,000 or 10,000 miles, depending on which engine you have, driving conditions, and whether you use conventional or synthetic oil.  The boyfriend’s 2004 Toyota recommends an oil change about every 5,000 miles on conventional oil, but he had been using a synthetic blend, which should go 8,000-10,000 miles pretty easily.  He had been following his mechanic’s advice about changing the oil every 3,000 miles instead.  Ouch.  That’s a lot of unnecessary oil changes.  I talked him into stretching it out, so now at least he shoots for 8,000 miles before taking it in.

For those of you who are telling yourself “well, my mechanic says every 3,000 miles is safest, and it’s like an insurance policy on your engine,” you can go ahead and keep getting too many oil changes, but you’re spending a lot more money and using up a lot of extra oil for no real benefit.  Today’s engines are built better and with closer tolerances (i.e., better machining) than they were 20 years ago.  That means less carbon buildup, which means the oil stays cleaner, longer.  There are good reasons why the oil intervals are more spread out than they used to be, so it’s not a conspiracy by manufacturers to have your engine fail sooner so you will buy a new car.  Besides, there are plenty of other things that break or become obsolete before your engine fails, and those are usually enough reason for people to buy new cars anyway.

Replace Spark Plugs/Wires Every 30,000 Miles

Back in the days of carburetors instead of fuel injection, the fuel/air mixture going into each cylinder was imprecise.  A little too much fuel in the mix could foul spark plugs pretty quickly.  A little too much air could fry the plugs.  Because it was so easy for the mixture to go one way or the other, the rule of thumb was to replace your spark plugs (and spark plug wires, while you were at it) every 30,000 miles.  A dead spark plug means a non-firing cylinder, and that can cause a significant lack of power and decreased fuel mileage.

But as cars got more sophisticated, the carburetor went by the wayside, and cars started using fuel injection.  Early fuel injection was still a bit imprecise, but at least there was some sort of computer governing how much fuel and air went into the mix.  That made spark plugs last a little longer, but still, the recommendation was to replace about every 30,000 miles.

Now think about how much computers have advanced from the early 1980s to today.  The same has happened for the on-board computer in your car.  Today’s fuel injected cars not only have a computer governing the fuel/air mixture in each cylinder, but they’ve got sensors monitoring the output of each cylinder to fine-tune the mix as you drive.  Today’s spark plugs can last a very, very long time.  My 2009 Toyota recommends the first spark plug replacement at 120,000 miles!  In my uncle’s Ford F-250 (2008 model, I believe), he’s got 140,000 miles on the original spark plugs.  The dealer said that the spark plug replacement in his truck is complicated and expensive (I won’t go into the reasons why here), so he said he would run the truck until you notice that it’s not running quite right, and only then would he bother replacing the plugs.

Again, checking the service manual is your best bet, and there’s no advantage to replacing the spark plugs any sooner, unless you notice that your engine is idling rough.  Then you might take your car in to figure out if the plugs need to be changed.

To be continued later this week…