Thanks, GAFIT. I somehow did not follow that you were contrasting 2nd gen. with 3rd gen.

 

Glad you asked.

I bought my '13 Fit new, so I am the only person who has ever touched the plugs. I have replaced them once so far. It was at about 55k mi. Far from being loose, all my plugs were tight. In fact, I had to use a breaker bar on one of them. I replaced them with OEM spec NGK, and I used a bit of anti-seize on each. With regard to your other post, I would not use Loctite on any spark plugs.

One last thing: Regular maintenance, like GAFIT has said, is a wise policy. "Regular maintenance" for some people will mean more maintenance than they are doing now, more maintenance than the factory suggest, more maintenance than the Maintenance Minder indicates. Most people hate this idea. Most car guys understand that cars need maintenance.

 

One way to hear that you have a loose plug is that you hear a ticking noise similar to a piezoelectric igniter on a propane barbecue or on a gas stove. Kinda sounds like smacking two little pebbles together. The sound is also at a steady rhythm with the engine.

when I caught mine, it was so loose, I didn’t think my socket was even on the plug. I was able to turn the plug about 10 turns with my finger tips and ratchet extension before it was seated. Retorqued it and have been ok since. The good news is that I never had any rough idle or noticeable loss of power from it, even if there is some combustion blow by.