Piston Slap: Earth Dreams of Carbon Buildup?
TTAC commentator KCFlyer writes:

Dear Sajeev,

I have a 2015 Honda Fit LX manual, purchased new. From day one I noticed a slight momentary hesitation under moderate acceleration when the engine was cold. I took the car to the dealer after a few weeks but they could not duplicate the problem. I dropped it off again and left it overnight, hoping a cold engine would allow them to experience the issue. No luck.

Fast forward 57,000 miles. Same problem persists and is reported to dealer via phone several times. The check engine light comes on. Dealer says the code means an #3 cylinder misfire. They say the fuel injectors are clogged and charge $1,300 to replace all four injectors. Honda of America throws in $1,000 of goodwill money because fuel injectors are not covered by the 60,000 mile powertrain warranty.

Two weeks later light comes back on. Same code. This time another dealer pulls the head and finds carbon buildup on all four piston heads. They clean up the engine, clean the throttle body and declare the vehicle fixed. Total charges paid for by Honda of America under goodwill claim except $217 for the throttle body cleaning. That was yesterday and I will know within days if the original problem persist.

Tech rep was awesome. He recommends I get the fuel injectors and throttle body cleaned every 30,000 miles. My question, what caused the carbon buildup? Does the buildup damage the engine even if later cleaned up? Should I dump the Fit? It is an awesome commuter. I average 44 mpg summer and 39 winter.

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  • FreedMike I guess some folks are just bound and determined to drive around with a grenade in their steering wheel.
  • FreedMike Bit dear, but these might have collector appeal, particularly one with 20,000 miles (assuming that's not a doctored figure) that hasn't had the full "whip" treatment.
  • Adam4562 I have Bluetooth in my car , the name comes up and I answer . It goes through the speaker. I’ll text on a stop sign or red light . If it’s really urgent hill pull over .
  • Dukeisduke I'll pick up my phone and look at a text or something else while at a red light, but when the light turns green, the phone gets put down.
  • Dukeisduke Haven't some cars been recalled multiple times (replacement airbags being recalled).