A1218

The engine produces a light clatter noise at idle. Is that normal? The Accord has a little over 29,000 miles only.It's probably been like that since new from what I can remember. Maintenance is done in a timely manner and I’ve kept up with everything so far. All maintenance I do myself. I have drained and filled the transmission so far, done oil and filter every time the MM comes on (Mobil 1 fully synthetic or Castrol Edge Fully synthetic), changed the engine air filter, cabin filter, and flushed brake fluid followed by bleeding. Everything was bought from Honda besides the oil. Anyone experience this? I’ve read an article online about excessive clearance from rocker shaft bridge that needs to be loosened and re-torqued? But like I have said it has been like that since new and I have heard it on another 2015 Accord v6. Any ideas? No performance issues whatsoever and it is not related to engine RPMs at idle in the park as I can rev it up all I want with nothing heard at all until it drops back to idling. You start hearing it once it's warmed up only as well. With the gear in drive, the noise goes away and is not heard while driving either. I cannot pinpoint an exact spot where the noise really comes from and the engine idles smooth as well. Cannot feel any odd sensations when putting my hand on it and when putting my ear close to the engine it doesn't even seem like the noise originates internally as well. I attached a clip that I uploaded to YouTube.

I got a U0155 code as soon as I plugged in my code reader to the vehicle.Coincidentally I installed the VCM tuner 2 earlier in the day after the vehicle sat for a few hours. I drove a few times after and there were no codes. I decided to check some live data out to see if the tuner was actually working, but as soon as I plugged it into the port the dash lit up with all the warning lights and check engine light. I cleared the codes and went on the road again after, nothing so far.Is there a specific sequence or way the scanner should be used? I plugged it in with the engine already on and it triggered instantly.I tried it back just now this time plugging the scanner in first then starting the engine and everything was okay.I did reach out to the tuner company and they said this situation is not a result of the VCM tuner.I honestly never used the code reader on the vehicle yet so I would like to know if I’m doing something incorrectly?