Weird noise on part throttle..

Blackbird

Leaving Skid Marks
Premium Member
Location
NSW
First Name
Steve
Drive
2001 ADM Evo 6.5 Makinen Edition,
2001 Legnum VR-4 Type S Written off,
2000 Legnum VR-4 Type S Manual with 23,489km!!
Ummm ,
Not sure if anyone has had this issue.
Had the car for 4 weeks. As far as a 12 year old car goes... it's perfect. Love my Legnum to bits!
its a 2001 FL VR-4 with 76,000 K's on it bone stock apart from a K and N panel insert.

Now... when I'm driving (usually happens in 5th but have heard it making this noise in 4th once)
I'm crusing along above 60kmh and on part throttle (30% throttle) a noise starts up (sounds like a deep woopwoopwoop, woopwoopwoop) Best I can describe it.

If I back off it stops, if I accelerate harder it stops. happens at all speeds on part throttle. It's not loud, and it can't really be heard outside,, just resonates in the cabin a little.. can't be tyres, I was thinking harmonic balancer or drive belts but they all appear ok?!

The turbos don't make any sounds indicating they are surging or out of balance (all smooth as silk)
The engine has lots of power and doesn't shake, hesitate or anything like that... I'm a little purplexed as to what this noise is?

Anyone else in VR-4 land heard of or had this noise?

Thanks
Steve
 

mookers

puri puri
Location
Frankston, Melbourne, VIC
First Name
Derek
Drive
CL9 Accord Euro Lux, GE Jazz VTi, Evil Supervillain Chair, Homemade Portable Square Drumkit
You've got a part-throttle dubstep generator hidden in your car?

Seriously, the only thing I can think of is that it's a beat frequency coming from your exhaust. But that would require another source of low-frequency noise to interfere with and create the beat frequency - in my car it only happens when I'm driving next to another car that has a similar pitched loud exhaust.

Reducing or increasing load with the throttle causes your exhaust frequency to change, and the beat disappears.

If there's no other sound source, then I've got no idea.
 

Blackbird

Leaving Skid Marks
Premium Member
Location
NSW
First Name
Steve
Drive
2001 ADM Evo 6.5 Makinen Edition,
2001 Legnum VR-4 Type S Written off,
2000 Legnum VR-4 Type S Manual with 23,489km!!
Its an auto....
Steve
 
G

Guest

Unregistered
Have you serviced the Trans? Or are there any sort of vibrations coming from it when it makes the noise?
 

Blackbird

Leaving Skid Marks
Premium Member
Location
NSW
First Name
Steve
Drive
2001 ADM Evo 6.5 Makinen Edition,
2001 Legnum VR-4 Type S Written off,
2000 Legnum VR-4 Type S Manual with 23,489km!!
Trans hasnt been serviced yet.. will do that very soon..
The transfer case does whine a little. The noise is appears to he coming from the right hand ( drivers side )
It resonates through the accelerator very faintly... on a smooth road
Only.

Steve
 

Blackbird

Leaving Skid Marks
Premium Member
Location
NSW
First Name
Steve
Drive
2001 ADM Evo 6.5 Makinen Edition,
2001 Legnum VR-4 Type S Written off,
2000 Legnum VR-4 Type S Manual with 23,489km!!
Mookers,
That is by far the best reply to a noise I've ever heard.. wow!
I just read up on beat frequencies and I do know of the exhaust tones in two different cars as I've heard it before.. sometimes quite humerous to listen to, Never thought I'd come across this in one of my own cars.. especially a stock car too....

Will keep that in mind if it continues once I start looking deeper after I service the thing completely, and if it still remains...
Many Thanks mate,

and indeed to everyone that's chimed in.. thankyou!
Steve


You've got a part-throttle dubstep generator hidden in your car?

Seriously, the only thing I can think of is that it's a beat frequency coming from your exhaust. But that would require another source of low-frequency noise to interfere with and create the beat frequency - in my car it only happens when I'm driving next to another car that has a similar pitched loud exhaust.

Reducing or increasing load with the throttle causes your exhaust frequency to change, and the beat disappears.

If there's no other sound source, then I've got no idea.
 

TommyG

Idling at the Lights
Location
SA
First Name
Tom G
Drive
2001 Legnum
Hey lads, thought I would chime in expressing a similar issue I have been experiencing lately. To best describe the noise it sounds like a helicopter or the sound you get when your rear windows are down! The noise only occurs when in low RPM (between 1500,2500rpm) in gears 3,4, and 5. Had recently replaced the diff with an SAYC which has been looked at and apparently there is nothing wrong with the diff, I have a drivers side front wheel bearing on the outs but I don't believe it could be the wheel bearing. Any ideas??
 

AKKO

2 AYC Bars
Lifetime Member
Location
WA
First Name
Chris
Drive
1998 Galant VR4 Type-V (Facelift)
By way of random noises brake dust sheilds were one I remember scratching my head over... sorry not much help I know.
 
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