Piston Slap: Beached Shark, Broken Diagnostic Tree?

Sajeev Mehta
by Sajeev Mehta
piston slap beached shark broken diagnostic tree

TTAC reader Tiburon Guy writes:

Hey Sajeev: Long time reader, first time e-mailer. I have a 2001 Hyundai Tiburon that I inherited from my wife when we got married (dowrys are making a comeback!). It has 70,000 original miles and I’ve maintained it properly. Recently a problem arose that the dealer could not point out nor could my personal mechanic (ASC Certified) determine the cause or solution to.

It’s an automatic transmission. Sometimes when starting the car, pushing the release button on the shifter is downright impossible. It’s stuck and won’t engage, which means I can’t shift into gear. After a few moments of wiggling and pushing and jerking (and crying on my wife’s part) it will give and we’ll be on our way.

This doesn’t happen all the time though, it’s once every month or so. Any idea what could cause this and if so, what can I do to fix or prevent it from occurring? We are the only owners of the car and have not raced or abused it. I’ve hunted the forums on the Hyundai fan sites and I can’t find anyone with the same issue.

Sajeev writes:

These brake-shift interlocks are a simple design: you push the brake pedal, the brake switch takes note, then a solenoid on the shifter releases it’s grip and you move out of park. And a competent wrench should find the offending part rather quickly.

The brake switch is simple, check if the brake lights illuminate when you touch the pedal. There’s probably a fuse, so the owner’s manual has you covered. Test the solenoid with a factory service manual (on-line or on paper) or pull it out of the shifter and stick 12v of juice at it. And removing the shifter might be a good way to check for binding in its mechanism. Let’s assume (hope?) this diagnostic tree was followed.

But if everything passed muster, perhaps the parking spot is the problem? Many cars are harder to move from park with a transmission “loaded” by the forces of an uphill parking space. And sometimes the transmission makes a terrible sound when the shifter finally moves out of park. The only solution is to engage the parking brake before going into park. And reverse the operation when you return: start the car, put the autobox in neutral or in gear, and release the parking brake.

More to the point, I suspect you can Cliff’s Notes my writing, post it on a Hyundai enthusiast forum and get a straight answer in a matter of hours. That’s my ultimate recommendation.

Bonus! A Piston Slap Nugget of Wisdom:

There is significant mechanical waste in modern cars, items that neither improve the driving experience nor make the car any safer. I suspect failed brake interlocks cause more stranded motorists, grey hairs, and unnecessary repairs than any potential lives saved from accidentally hitting the wrong foot pedal after start up.

Plus, the extra dollars added to a car’s MSRP are better spent on a fancy dinner with that special someone. And with that, I’d like to thank 60 Minutes for giving us this electrical pain in the ass, and make the obligatory hyperlink to Paul Niedermeyer’s excellent article on the Audi 5000.

(Send your queries to mehta@ttac.com)

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3 of 19 comments
  • Disaster Disaster on Mar 08, 2010

    This might not pretain to the 2001 models, but the 2003 Tiburon made the Consumer Reports "Least Reliable" list, with 161 problems per 100 vehicles. In comparison, the 2001 Toyota Echo only had 35 problems per vehicle.

    • Don1967 Don1967 on Mar 08, 2010

      Actually, this might not pertain to anything at all.

  • Don1967 Don1967 on Mar 08, 2010

    Regarding Sajeev's first remark about parking on slopes, I agree and further suggest angling the front wheel solidly into the curb until the vehicle virtually stops on its own. Then engage the parking brake, then shift into Park. Many vehicles - and almost certainly a 9-year old Tiburon - lack a sufficiently strong parking brake to prevent gear binding on slopes.

  • Slyons My guess is they keep the 2.0 liter they have now with minor tweaks, and shoehorn in the 48V mild hybrid system that just debuted in the CX-90. Should allow for all the regular fun of wringing out the 4 cyl and bump the fuel mileage up at least a couple points. I don't think we'll see a major evolution of the drivetrain until the next next model (NF?).
  • 28-Cars-Later " as long as internal-combustion engines exist?"So... forever until society collapses, rebuilds, and then the Hunger Games begin?
  • Jeff S It would be a neat project but the 6k should include the parts car.
  • Kcflyer Why oh why does every manufacturer slop the roof so much on vehicles that are supposed to be utilitarian? Especially a three row people mover. Let the rear roof square off like an old volvo wagon for cripes sake! And get off my lawn. And don't give me the mpg noise. I'd happily give back a couple mpg for some utility in a "utility" vehicle.
  • Varezhka KISS, just like Miata always has. No exotic powertrain options, a simple 2L NA with MT with similar power output as Mazda3 and CX-30 would best match the car; as much as I have always dreamed of a rotary powered RX-5.That said, the Miata that I actually liked and driven the most was NC. It was just practical enough and comfortable enough over long distance that I can actually use it as my DD/road trip vehicle without losing the lightweight nimble feeling. ND as nice as it is lost some of that IMHO.The only other thing I'd like would be the new MazdaConnect which is so much nicer, and a less angry face.