DCT clunk when slowing to a stop

M

matsmith749

Active member
Site Supporter
This is my second BMW 35is with a DCT box - never noticed it in my 1st one, but this car has a definite 'clunk' from the gearbox as you approach a stop.

It's every time you approach a stop, off the gas, car shifts down from 4th / 3rd etc nice & smooth, but just as you are at 5mph or so approaching the stop there is a clunk that sounds muted, but similar to a loose item in the boot shifting. You hear it, and feel it.

Gearbox operation seems fine - my question is, how typical is this? Should I be concerned? I have read the manual & it says to expect noises from the DCT.

Car is under BMW warranty & going in for a service tomorrow, does this need to be raised?
 
Mine makes the occasional clang, but rarely. I would ask if you get it regularly especially as you have a warranty.
 
Could be slop in the drive train

I had something similar when rocking on off the accelerator at modest settings

I replaced the guibo and rear support bearing

The guibo looked in pretty ok condition when removed less so the rear propshsft bearing

Otherwise maybe bushes in rear subframe / suspension

Is it worse on different road surfaces?

I’ve got the DMF looking like it’s going but that’s not yet making an obvious noise
 
B21 said:
Could be slop in the drive train

I had something similar when rocking on off the accelerator at modest settings

I replaced the guibo and rear support bearing

The guibo looked in pretty ok condition when removed less so the rear propshsft bearing

Otherwise maybe bushes in rear subframe / suspension

Is it worse on different road surfaces?

I’ve got the DMF looking like it’s going but that’s not yet making an obvious noise
Click to expand...
Id agree with the drive train conmment, prop centre bearing etc.
Can you clarify is it a metallic noise or softer?
 
It’s a clunky - like a tin of beans hitting the back of the boot. Muffled - but solid.

Will see what they say at BMW tomorrow
 
Had a call from the BMW dealer - they cannot hear the clunk.

On my way down there this afternoon so I can 'demo' it
 
So yeh - went to demo the noise & it didn't make it. Agreed to just monitor for now & report back if it gets more obvious :)

On another note, this BMW dealer went to town on checking the car over whilst it was in for a brake fluid change. They found £1100 worth of issues that should have been resolved as part of the AUC selling process by the other BMW dealer (I bought it 2 hrs away from where I live).

Happily they have agreed to pay up & the car is getting all sorts of tweaks prior to me getting it back.

Weirdest was that the bonnet struts are 'past their use by date' - apparently they are good for 5 years on a z4 & then should be replaced. Something to do with the pedestrian safety systems.

Sounds like nonsense to me & they were working fine, but hey-ho, replaced at BMWs expense :)
 
matsmith749 said:
Something to do with the pedestrian safety systems.
Click to expand...
these are different than the bonnet struts. They are under the corners of your bonnet on each side near the windscreen and push it up if you hit something to deflect it. Ouch! :D
 
Yep - but it’s not the explosive charge that they replace.

Part number on the invoice is
2x B51.23.7.285.823 N/STOCK Gas spring

It’s the actual bonnet gas struts - from what I was told, the explosive bit does not expire. In the event of a slow speed collision, the ecplosive charges fire, which shifts the position of the bonnet hinge.

This then allows the lifting of the bonnet, but that is performed by the standard gas struts.

I'm learning - but not 100% convinced.

Have I got it wrong?
 
You must log in or register to reply here.
Back
Top Bottom