Noise Under Car When Accelerating

[Rudycm]

I have an '01, 3.0 with a very weird noise coming from under the car. Its a sharp mechanical-slipping noise that can be heard and felt only when I accelerate moderate to hard from a standstill, whether fwd or rev. Its not a clunk, but more like a clink sound that increses in frequency depending on how much throttle I use and lets up as the momentum of car increases.

Sounds like that straining mechanical noise you hear/feel when fully engaging your ABS, but louder and apperas to come from the bottom rear, middle and other times from the front. I can avoid the problem by being ginger on the throttle. Performance itself does not seem afected though hard to tell. Noise definitly coming from undercarriage and loud enough to be heard by pedestrians.

Can noise be related to self leveling system, or torque converter or transfer case?

Any thoughts?

[deeph203]

Hi there.I have the same car same with you.And I have the same noise.They said that this noise comes from the transfer case.I don't know much more but I think that it has to be replaced with new one.That's what they said to me.But it's only the noise it won't affect anything else in the car.That's all I know.If you hear something else please tell me

[Rudycm]

Originally Posted by deeph203

Hi there.I have the same car same with you.And I have the same noise.They said that this noise comes from the transfer case.I don't know much more but I think that it has to be replaced with new one.That's what they said to me.But it's only the noise it won't affect anything else in the car.That's all I know.If you hear something else please tell me

Thanks for the info. Transfer case was just my best guess per the symptoms described. My concern is that without knowing source of noise other damage may occur.

Was it the dealer who diagnosed it as the xfer case? Do you feel your performance is affected at all?

I ll let you know what else I come up with.

[deeph203]

A technician of bmw diagnosed this problem.Next friday I'm going to take my car there for further informations.I can't understand anything about performance cause I've got nothing to compare with.I mean another car.I feel that the performance is ok.I'll let you know

[deeph203]

Rudy I just took my car from Bmw service.They said that I have to change transfer oil and transfer nexus.If noise remains I have to change the transfer case.They want 6000euros for the case.That's a serious problem I think.I bought this car two months ago from a car shop in Germany with two years guarantee.I'm in Greece now.Anyone knows if I could do anything with the guarantee.I don't know what to do.Any help???

[chubyball]

what is the transfer oil and transfer nexus? Where do they locate?

[deeph203]

Originally Posted by chubyball

what is the transfer oil and transfer nexus? Where do they locate?

I don't know my friend.They said that the transfer case has oil and a wire netting.

[Rudycm]

Jut paid $3200 to repair bad transfer case @ 85K miles.

Do you use sport shifting a lot? or accellerate in 1st gear regularly?
__________________

[deeph203]

You said you repaired the transfer case?You didn't change it?
I don't use sport much and I don't accelerate with 1st gear often.Why do you ask?

[Rudycm]

It was replaced, just meant the problem was repaired. The xfer case was entirely shot by the time I took it in. It was only putting the power to the rear and not the front. Whatever BMW did, my tranny shifts better, it feels stronger and my gas mileage has actually improved.

This is my first automatic car, so i have a tendency to manually up/down shift quite regular in sport mode. Failing any obvious reasons, I was curious how a transfer case would ever fail under normal highway driving on Florida flat roads and if excesive torque starts "as I often do" might strain the gears over time.

Maybe I need to tone down my driving habits. With my style of driving im relentless so if theres any weakness anywhere in the drivetrain Im sure to discover it the bad way. I've toasted driveshafts on my 6 and 3 series several times before....if that tells you anything!