Hi All,

I've begun noticing a slight whirring sound, best way to describe it, during light acceleration only whether the car is warm or cold. Anyone else notice this?

 

Is it drive train related like the noise we hear from the cylinder deactivation? Does it go away if you downshift with a paddle shifter?

 

This happened on my civic Si but only when it got over 100K in 4rth and 5th gear and it has always been serviced.

 

I've not tried using the paddle shifter at the time. I'll certainly try that next time I hear it.

Yes, it sounds like its drivetrain related. I feel a slight vibration through the car when there is cylinder deactivation, this is different though as one cannot feel it.

 

I dont think it is cylinder de-activation. It should be most pronounced at highway speeds when cruising etc. The only "whirring" sound i hear is twice around 20-30 mph that too once when the car goes from complete stop/ cold. I dont hear the same sound when taking off from a stop light etc.

I believe it is some system turning on. I dont know what.

Another rumbling feeling is when I am cruising @ 30-35 mph inside the city. It seems the car tries to get in 5/6th gear as soon as possible and this rumbling is just the selection of a wrong gear. I haven't seen/ felt this rumbling when in S mode.

 

I have noticed a whirring notice on acceleration. I thought it could be the tranny winding up, but have isolated it to the engine. It reminds me of a sewing machine winding up or a jet engine humm, but have accepted that this is just the revs of the engine and the normal purring of the motor.

I'm hoping others hear this as well, or I've got big problems......

 

I just noticed it last night....I had my car for 8 months and never noticed anything, until last night....strange. When I bring it in for service I will tell them about that and the odd wind noise coming from the rear passenger door.

 

Sorry, didn't mean to create problems for you

Let us know what they say. I have a while before my first service but will update when I do take it in regarding this matter.

 

I notice the same "whirring" noise on my 13 RDX as well. Only at relatively low speed, typically when coasting and not under acceleration. Only have about 700 miles on it, so it will be a while before my first service. Almost sounds like a wind related noise, but its not becase it stops when I accelerate.

 

Same here, a whirring or high pitch kind of whine while driving at city speeds. It seems to go away when I take my foot off the accelerator, then returns when I am back on the gas. I thought it might be related to the noise cancellation but that is just a guess. When I turn up the stereo it seems to go away. :-D

 

^^ Could this be the propeller shaft?

 

Hmmm, interesting thought. When the engine is under load some of the power is directed to the rear wheels, however when the throttle is not depressed the clutch plates are disengaged hence the prop shaft is not turning. Alternately, could this sound be coming from the hydraulic pump?

 

Actually the propeller shaft always turns with the front wheels. The clutches that engage and disengage the rear wheels are located in the AWD unit located after the propeller shaft between the rear wheels.

 

GRDX....So what do you think, do you think some of the noise people hear could be the propeller shaft?

 

I had purposely not offered my opinion since without hearing it and the description being somewhat vague makes it difficult. However since you asked I would say it is possible it may be the propeller shaft but it is also possible it may be one of the four axle shafts among other things.

 

So today I took the lead mechanic of my friendly neighborhood Acura dealership for a road test to point out the whirring sound (amongst other things). There was no mistaking the noise under light throttle application, which starts at exactly 50 km/hr. Immediately he told me that he is aware of this issue, and so is Acura. All he could tell me is that they do not know what is causing it, and that the engineers are working on it. He thinks it is gear noise, probably coming from the transmission (just his opinion).

I'm not a mechanic, but I have a pretty good understanding of things mechanical. My guess is that maybe one of the tooth angles on a gear may not be cut at the right angle, or something is not properly aligned (not meshing properly). Just a thought.

 

Keep us posted on your progress!

 

Got a call from the dealer today. They are going to change out the front diff and send it back to Honda for some reverse engineering.