Strange Noise M35 Arx

[[[d a n n y]]]

It's really hard to explain this noise..

it only happens on half throttle 3-4K rpm

it makes this grinding noise...

like a chair being dragged along a wodden floor.

and the noise is audibile from outside and it's really loud..

[zei20l]

exhaust vibrating on something?? some other component vibrating on something???

is it coming from the back or front? low/high speed?

[[[d a n n y]]]

low high speed doenst matter as long as im in the 3-4K rpm in any gear half throttle

front half of the car

[mxfly]

I'd say wheel bearing, either right or left. I had the same problem and it gets louder as speed increases. Does that happen to yours?

[zei20l]

probably a belt slipping or something is vibrating because its not tight enough. does it happen when you free rev it?or only while youre moving?

if you can get someone to rev the car, you might get a better indication of where its coming from. i rekon exhaust or something simple like that. airbox, anything thats connected to the engine thats come loose slightly.

[[[d a n n y]]]

only under load

and no it doesnt get louder on speed

it's not constant..

only at 3-4K rpm only half thorttle then when i full throttle it it goes away

[zei20l]

yup, something is loose, sounds like a harmonic resonance thats causing something to vibrate

is it metallic sounding?? might be a blown gasket too, but unlikely

[[[d a n n y]]]

yup, something is loose, sounds like a harmonic resonance thats causing something to vibrate

is it metallic sounding?? might be a blown gasket too, but unlikely

hm.. not quite metailc but it sounds like sumthing rubbing against the chassis or sumthing at high speed

u can feel the vibration inside the cabin too

[mxfly]

OK my next guess is a loose belt.

[zei20l]

ahhh in the cabin, ok loose/broken engine mount..... get a mechanic to check it out, do up bolts. or hop under the car and start torquing bolts up

[[[d a n n y]]]

lol already did all that

yeah feel the vibration inside and hear it

and also the noise is there from outside too

checked all belts cuz of that i spend 1.3K on a full service staright after i got my car

but the noise was still there

im ruling out diff problems too cuz i changed the syncro and all that setting around and the noise was still there

it's gota be sumthing mechanical

[zei20l]

actually 3-4k........... check the fan too. maybe the viscous coupling is fooked?

[[[d a n n y]]]

if the coupling was gone would it be making noise all the time

[zei20l]

are you sure? the get faster with RPM, and also with heat

[[[d a n n y]]]

speed increase doesnt make a difference at all

it's just the RPM

so im guessing engine side not diff g box side

[iamhe77]

I know that sound.

It started after my turbo was done, but only sometimes and under full boost (yep around 4k).

If I take my foot off the accelerator, the noise disappears. Then it says gone when I put my foot back down.

My mates RS is starting to do it (so he says, I haven't heard it).

It is not possible to replicate as it happens to me us at random times.

No Danny, I do not know what it is!

Thought it might be an oil supply prob to the turbo, nothing to do with belts

[Clowndog]

I am getting the same sound, and have done since i got the car about 2 months ago. hasn't gotten any worse tho, and doesn't happen alll the time. You're right about the rev thing - it happens to me at about 3 grand, only while pulling through torque at higher gears. if the auto kicks back, or I use manual mode, then it doesn't happen. feels like about 3rd or 4th gear. It's really hard to say the sound is consistant tho, I think it doesn't really happen all the time.

[zei20l]

how about a blockage in the exhaust??

[iamhe77]

how about a blockage in the exhaust??

Doubt it.

[Jetwreck]

only under load

and no it doesnt get louder on speed

it's not constant..

only at 3-4K rpm only half thorttle then when i full throttle it it goes away

Sounds like Turbo time!!!....sounds sort of like a slipping clutch or a rattling sound?.....only under load? Is it there all the time? Does it do it under full throttle?