Whining noise from VTEC?

[Klas]

Hi.

In the end of last season on my way to a track day I got a whining noise at high revs but did not investigate further. After maybe an hour on track the rear O2 sensor whent bad so I drove home carefully at low revs. The oil was at top mark on stick, maybe little over even and oil pressure ok all the time.
This winter I changed the O2 sensor and installed a baffle in the oil pan.

When starting up after a winter idle/service every thing seemed ok, after the engine was warm I started to rev and sadly the noise was still there. If I engage a gear and accelerate moderately I can hear that the whining start when VTEC engages and at 6.200 revs the sound is very distinct. The higher the rev the higher the volume of the whine.

The sound is the same no matter what gear used.
No engine codes.
I only tested to rev with the engine warm.
Oil level have been little over top marker all the time (I track a lot).
Air filter was a bit wet (15% of the area) from oil.


Have any of you had the same symptom?
What in the VTEC system might cause this sound?

Regards
Klas

 

[C-speed]

Can you record the sound for us by chance? There's nothing in the VTEC system that would cause a whining sound. Only spinning things would whine, like the timing belt, tensioner, water pump, etc...

You sure its not noise coming from your speakers?

 

[StmpoRaceProducts]

I dont beleive anything in the vtec function would cause a whining sound.
Sounds like something connected with your belt drives, t-belt tensioners, surp belt tensioners, a/c tensioner etc.

I may have you to beleive its in the vtec function cause its happining at high RPM's. Eliminate vtec. unclip the soleniods and take it for a spin and see if the sound is still present. (dont rev to high) If so, you'll know its not coming from that....and if you get a cel, disconnecte the battery for a sec, it will only be a soft code.

check tensioners and make sure there in good shape.
Vtec being the problem is very unlikely IMO

 

[nsxotic911]

Check your grounds, make sure it's not alternator whine which will be most noticable higher RPM's you go.

Check the ECU mounting, make sure it's not lose. It could be coming from that too. I have some whine/electric noise from the ECU. Not sure if it's normal..

Does it happen if you raise the RPM in neutral?
Hear anything from the individual relays in the switch boxes?

 

[Briank]

Pull off the alternator belt and try it and see if the sound goes away if not then take off the AC belt and try it again.

 

[OLDMNSX]

Pull off the alternator belt and try it and see if the sound goes away if not then take off the AC belt and try it again.

I'm with Brian on this one too!

 

[Klas]

Thank you all by your input.
I don't think the sound can be recorded, I only hear it in the cabin. Outside it's to much noise from the exhaust so I cant here the noise at all from the outside.
The VTEC theory is without any substance I just wanted it to be something around that rev but it is not. The sound start to be noticeable at ~5.600, at 6.200 no one can miss it.
The sound is the same in gear or in neutral, moving or stand still.


I removed the whole radio so it is not the speakers.
I removed the a/c belt and the alternator belt – no change.
I adjusted the valves during winter too so its not that.

Is the fuel pump rev dependent? Could it be that?

Come to think of it, I removed the engine cover last year. Could it be that the sound was there, maybe even should be there but I didn't here it before?

 

[NSXFRIEND]

Possible exhaust leak or lose flanges? Have you changed the timing belt water pump, a squeeling waterpump occurs when it has failed/locking up. Only other thing I can think of is your accessory belt and tensionar. Is the airfilter box OEM if not put it backin see if that solves it.

Keep us posted.

 

[Klas]

Hi!

Almost a year later I managed to disassemble the car to change water pump and timing belt using Gary Kentosh's excellent guide. First question is, from the service manual and Gary's guide the cam gears should point to each other and the flange on the crankshaft is facing up. On my there seams to be an offset. When the pin punches is inserted in the cams the TDC mark does not align and the flange on the crankshaft is at 11 a clock.

I dont understand how this misalignment can be. Should not the pin holes in the camshaft be at #1 TDC and if so how come that all the cam gears is misaligned? The car used to run great and lap times indicate that the engine had good power.

 

[goldNSX]

Having power is not a good indicator for correct installation. An exhaust sniffer test will tell much earlier if anything is wrong.

BTW: what about the noise?

 

[Klas]

The noise is not solved, the car have been on jacks the last year

The emissions is good. From the last Vehicle Inspection all 4 values was good. CO 0.0, CO 2500 revs 0.1, HC 6, Lambda/O2 1.00.

 

[goldNSX]

The emissions is good.

The timing is good then.

 

[Klas]

Fixed!

Fixed! Probably the water pump.

 

[swerve2007]

bad bearing.