Strange noise behind passanger seat

[NSXDOC]

Hello all,
I am on my second NSX. I just got a 2005 and love it! What is interesting is that both my 91' and the 05' made a light sound when traveling above like 20 mph or so. It is not directly related to acceleration and the car has to be moving. It sounds like it comes from just under the window behind the passage seat. The noise is kinda rattling but also kinda like when you need a ground loop for a car stereo (winnyish).

 

[Thunder]

can you better describe the noise? noise of shock? continuous or intermittent? metal or different?

 

[NSXDOC]

The noise is kinda high pitched it changes pitch with speed but not acceleration.
I can only hear it when the radio is off (the noise is fairly faint). What is weird is that I heard it in both my 91' and now in the 05'. I don't notice any problems I just though it was more than coincidence since I heard it in both. When I had my 91' worked on i had a suspension expert in the car and he did not know what it was.

 

[EdinKali]

Almost sounds like your amps are picking up the ignition pulses. If the wrong spark plugs were used you may get some electrical interference that that amps may pick up.

 

[NSXDOC]

Ya I thought that but the radio is off and it is only with speed not increased RPM's. I was really trying to pay attention last night while i drove to Denver. There is actually 2 noises. The Winny high pinched noise with increased speed, but also a noise that is like a metal point being pulled across glass or a chalk board. This 2nd noise is only on rough roads and is heard above the increased general road noise only louder and behind the passenger seat.

 

[arista5]

Ya I thought that but the radio is off and it is only with speed not increased RPM's. I was really trying to pay attention last night while i drove to Denver. There is actually 2 noises. The Winny high pinched noise with increased speed, but also a noise that is like a metal point being pulled across glass or a chalk board. This 2nd noise is only on rough roads and is heard above the increased general road noise only louder and behind the passenger seat.

to me it sounds like a brake pad sensor by your decsription.
does it go away when you tough the brakes?

 

[docjohn]

Ya I thought that but the radio is off and it is only with speed not increased RPM's. I was really trying to pay attention last night while i drove to Denver. There is actually 2 noises. The Winny high pinched noise with increased speed, but also a noise that is like a metal point being pulled across glass or a chalk board. This 2nd noise is only on rough roads and is heard above the increased general road noise only louder and behind the passenger seat.

could it be a main relay fiziling? could you have a idler pulley bearing going bad.

 

[pgilliam1]

Hello all,
I am on my second NSX. I just got a 2005 and love it! What is interesting is that both my 91' and the 05' made a light sound when traveling above like 20 mph or so. It is not directly related to acceleration and the car has to be moving. It sounds like it comes from just under the window behind the passage seat. The noise is kinda rattling but also kinda like when you need a ground loop for a car stereo (winnyish).

Since it was common on both cars and not causing problems, I'd say that's the way it should be. It's when the noise stops that you're gong to have problems. Happy Motoring!

 

[Acura NsX Pilot]

Just leave the radio on :biggrin:

 

[KrayziE RussiaN]

I say it's a gremlin! Just don't feed it after midnight and don't drive in the rain!

 

[silverNEEK]

I have an odd noise on my 04, sounds like it is behind the passenger seat, kindda tinging metal like rattle, very low and usually not noticeable. Not associated with the radio. Not sure if that is what you hear, I have not tracked down the noise yet.

 

[OLDMNSX]

I seem to have those same noises when I go from the garage into the house. They usually come after I have worked on my car for anywhere from 5 minutes to 5 days. The noise usually goes away when my wife goes out of town. Do you think that there is any relation between my wife being home or not?

Brad

 

[Nick675]

For everyone with this issue it is the computer behind the passenger seat on the firewall. If you pull the long trim that goes across the driver/passenger below the rear glass and look dead center behind the passenger seat you will see the metal cover of the computer there causing your trouble. I had the same issue. Just use some duct tape and go back to driving. Have fun.

 

[nsx_2k]

Is the noise coming from the metal clip of the upper rear bulk head cover tapping the computer? If so, your recommendation is to cover the computer with duct tape to reduce the chatter between the computer & cover?

 

[Nick675]

Is the noise coming from the metal clip of the upper rear bulk head cover tapping the computer? If so, your recommendation is to cover the computer with duct tape to reduce the chatter between the computer & cover?

The computer has a thin metal lid to it and buzz's against itself. Just put some tape either between the metal lid and computer or tape around it so it doesn't move.

 

[BobK]

Can you hear it if you open the engine lid and bring the revs up? I had that kind of noise (whining) and it turned out to the idler pulley bearing as someone else stated. My guru pressed out the old bearing pressed in a new one and in less than an hour I was back on the road for around $100 bucks.

 

[alum04org]

I have an odd noise on my 04, sounds like it is behind the passenger seat, kindda tinging metal like rattle, very low and usually not noticeable. Not associated with the radio. Not sure if that is what you hear, I have not tracked down the noise yet.

Yes! We have two Suzuka built NSX's, a late 2004 and an '05, and both have this tinny rattle. My service tech (reputable Acura NSX mechanic) could not hear it on a lengthy test drive in the 2005 - working too many years around air tools :frown:. So he went underneath, 'cause I thought it might be a heat shield that needed a tune up. (What do I know?)
Still there.

For everyone with this issue it is the computer behind the passenger seat on the firewall. If you pull the long trim that goes across the driver/passenger below the rear glass and look dead center behind the passenger seat you will see the metal cover of the computer there causing your trouble. I had the same issue. Just use some duct tape and go back to driving. Have fun.

The computer has a thin metal lid to it and buzz's against itself. Just put some tape either between the metal lid and computer or tape around it so it doesn't move.

BIG thank you, Nick. After going through the above, this was my next best guess - something on the cabin wall behind the passenger's seat - as sometimes it seemed that we could almost eliminate the tinny rattle by adjusting the passenger's seat back against the "bulkhead." Will pursue this.

 

[NSXDOC]

THANKS GUYS! This is such a great forum! I really appeciate the replys. :biggrin:

 

[alum04org]

I have an odd noise on my 04, sounds like it is behind the passenger seat, kindda tinging metal like rattle, very low and usually not noticeable. Not associated with the radio. Not sure if that is what you hear, I have not tracked down the noise yet.

Thread revival time! NSX's built Suzuka (39 at end of 2004 M Y, and all known 2005's as they were produced at Suzuka, as well).

For everyone with this issue it is the computer behind the passenger seat on the firewall. If you pull the long trim that goes across the driver/passenger below the rear glass and look dead center behind the passenger seat you will see the metal cover of the computer there causing your trouble. I had the same issue. Just use some duct tape and go back to driving. Have fun.

Yep.

Is the noise coming from the metal clip of the upper rear bulk head cover tapping the computer? If so, your recommendation is to cover the computer with duct tape to reduce the chatter between the computer & cover?

The computer has a thin metal lid to it and buzz's against itself. Just put some tape either between the metal lid and computer or tape around it so it doesn't move.

Yep.

Yes! We have two Suzuka built NSX's, a late 2004 and an '05, and both have this tinny rattle. My service tech (reputable Acura NSX mechanic) could not hear it on a lengthy test drive in the 2005 - working too many years around air tools :frown:. So he went underneath, 'cause I thought it might be a heat shield that needed a tune up. (What do I know?)
Still there.



BIG thank you, Nick. After going through the above, this was my next best guess - something on the cabin wall behind the passenger's seat - as sometimes it seemed that we could almost eliminate the tinny rattle by adjusting the passenger's seat back against the "bulkhead." Will pursue this.

UPDATE 6-10-2016: Inserted a mouse pad! Hillbilly fixed. :redface:


Yep, and now resolved on both Suzuka produced NSX's :wink: :smile: :biggrin:

For the record, I break most everything I try to take apart. Justin at Source One handled the 2004 Imola. Brian (sca037) handled the 2005 LBBP today. The following pics are in reverse order -