I recently purchased a 2015 LX, 6MT. It has 62k on the odo. Everything with the car is great so far. However, when I’m at a stop and the car is in neutral, I can hear a quiet sort of “whirring” noise coming from the engine bay (I’m assuming it’s the transmission). When I push the clutch in, the noise stops. It’s not loud enough to be heard outside of the cabin or even in the engine bay itself, only when I’m in the car. I’ve tried to take videos of it but it cannot be heard on video. I’ve seen a few other posts that claim this is normal for Manual Fits. However, I’ve also seen posts that say it is not normal and is a possible input shaft bearing issue. Could anyone with a 6MT weigh in on this for me and give me some potential piece of mind?

Thank you!

 

Mine (2019 EX MT6) occasionally makes somewhat loud whirl with clutch engaged, but just occasionally. No idea why.
Certainly with clutch engaged, there are more things rotating, so well, who knows?

2015 is now 7+ years ago, so if it hasn't been done yet, you should change the transmission fluid.
Most people recommend sticking to Honda fluid. I put AMSOIL manual synchromesh transmission fluid (MTF, 5W-30) in mine.

Drain plug is basically (completely?) identical to motor oil drain plug, with 14mm inner diameter crush washer (94109-14000).
Fill plug is bigger, with 20mm inner diameter crush washer (94109-20000).

I also replaced the drain plug with a magnetic one.

 

Is there any chance that this could be the radiator fan cutting in and out?

 

Not unless radiator fan behavior is tied to clutch pedal activity

 

Throw-out bearing, I'd guess.

 

I haven’t changed the transmission fluid yet, nor do I think it’s ever been changed. I’ll get it done tomorrow and report back!

 

Here’s a video with the noise itself.

 

+1
At 62k, you more than likely have the original fluid in there.
According to the "severe service" manual from Honda, the trans fluid should be replaced every 3 years or 60kms (37.5 k miles).
At this point, you are well overdue for a change.

 

Trust me, I’m aware. Like I said, I just bought the car used maybe 1.5-2 weeks ago. Changing transmission fluid this evening.

 

I checked mine (2015) and maybe makes a bit of noise but not really unless I concentrate intensely . I changed out the MTF with Honda fluid about 2000 miles ago (60000 miles).