Z4 sDrive 35iS rattle noise

[IDD]

Hi all,

New here so I'm sorry if this has been covered before but I could not find anything.

I have got a Z4 sDrive 35iS and it is amazing. My only issue is that it has this awful rattling noise when I stop accelerating. It happens more and more when the car has been put into sport or sport plus (after pops and bangs) or even when putting your foot down on accelerator (when it kicks down to a low gear)

Here is a streamable link to the sound. It is mostly heard towards the end of the clip

https://streamable.com/y5mj0t

Any advise on what it is, how to fix it or even how expensive it would be to take to a garage - would be great.

Some things to note: The car has had an aftermarket exhaust put onto it. I am not sure on when it was done or which exhaust is on it as it came like this when I got the car.

thanks

UPDATE 1:

Had my Dad (a mechanic) listen to the sound and to locate the sound.
It doe sound like a wastegate rattle but the rattle does not come from that area of the car. It sounds more like an exhaust leak which is causing the rattle.
The rattle is based around the front of the car.
When revving the car to listen to the rattle, we noticed a noise almost like silent farting from the front of the car near exhaust pipes.

Will update once I've had it on the ramp

UPDATE 2:

Been on the ramp today and have been told it is the turbo actuator. Not sure on cost to fix as of yet.

 

[Zforbes]

Welcome to this forum and 35iS ownership, you may get a better response by introducing yourself and posting some pics of the car in the newbies section

There are quite a few knowledgeable folk on here and good knowledge of this model.

Not sure you will get a positive diagnosis from the clip posted although I maybe wrong, I'm not aware of an obvious common failure with the exhaust rattle although someone with more knowledge maybe able to help.

If it was mine though I'd be checking out the exhaust gaskets back to the downpipe, turbos first but that's just a guess as a starting point. Had a similar type of rattle years ago on a Nissan 200sx, sounded much more sinister than what it turned out to be.

 

[IDD]

Thanks for that! I have just posted in there now.

I hope its not a serious underlying issue

 

[Chippie]

Hi and welcome to the forum
Sounds like it could be turbo waste gate rattle, see link below

https://youtu.be/JGG-At2Ks-E

 

[Zforbes]

Hi and welcome to the forum
Sounds like it could be turbo waste gate rattle, see link below

https://youtu.be/JGG-At2Ks-E

Sounds likely, what's the mileage?

 

[Zforbes]

Hi and welcome to the forum
Sounds like it could be turbo waste gate rattle, see link below

https://youtu.be/JGG-At2Ks-E

Sounds likely, what's the mileage?

 

[Pondy]

Some things to note: The car has had an aftermarket exhaust put onto it. I am not sure on when it was done or which exhaust is on it as it came like this when I got the car.

Judging by the advisory on the MOT in 2020 and not in 2021, I would say somewhere between these dates.

Did you not get a warranty with the car (if bought from a dealer)?

 

[IDD]

Hi and welcome to the forum
Sounds like it could be turbo waste gate rattle, see link below

https://youtu.be/JGG-At2Ks-E

Sounds likely, what's the mileage?

Mileage is at 111k currently

 

[IDD]

Some things to note: The car has had an aftermarket exhaust put onto it. I am not sure on when it was done or which exhaust is on it as it came like this when I got the car.

Judging by the advisory on the MOT in 2020 and not in 2021, I would say somewhere between these dates.

Did you not get a warranty with the car (if bought from a dealer)?

Hi,

I checked the dealership and this is what they pitch on the advertisements
" All our cars come with a clear Hpi certificate and 3 months warranty. "

I have not had the car for 3 months yet

 

[IDD]

Hi and welcome to the forum
Sounds like it could be turbo waste gate rattle, see link below

https://youtu.be/JGG-At2Ks-E

Sounds very similar but it also happens below the 5k revs that the video mentioned.
Any idea on how much these cost to fix - if that is the issue?

 

[Pondy]

Sounds very similar but it also happens below the 5k revs that the video mentioned.
Any idea on how much these cost to fix - if that is the issue?

Two turbo rebuilds on my N54 (same engine) was about £1,600 two years ago. :|
Don't want to rub salt in but do you know if the two front shocks have been sorted? These show up as possibly leaking on the last MOT. As they are adaptive, they are expensive to replace aswell.

 

[IDD]

Sounds very similar but it also happens below the 5k revs that the video mentioned.
Any idea on how much these cost to fix - if that is the issue?

Two turbo rebuilds on my N54 (same engine) was about £1,600 two years ago. :|
Don't want to rub salt in but do you know if the two front shocks have been sorted? These show up as possibly leaking on the last MOT. As they are adaptive, they are expensive to replace aswell.

Hi,

Yes, I got these sorted out before agreeing to take the car. Only issue I have faced is the rattle - as of yet...

 

[Pondy]

Yes, I got these sorted out before agreeing to take the car. Only issue I have faced is the rattle - as of yet...

That's good then
Personally I would get in touch with the seller, make them aware, then get a diagnosis from somewhere that know BMWs and go from there.

 

[Zforbes]

Hi and welcome to the forum
Sounds like it could be turbo waste gate rattle, see link below

https://youtu.be/JGG-At2Ks-E

Sounds likely, what's the mileage?

Mileage is at 111k currently

Could be why it's not that common on the 35iS then as most cars on here are quite low mileage, doesn't detract from the car though it should give you the same pleasure a a 20k mile car

It would good to feedback on this thread for future knowledge confirming outcome, all too often we read of problems highlighted but no conclusion

 

[Chippie]

Hi and welcome to the forum
Sounds like it could be turbo waste gate rattle, see link below

https://youtu.be/JGG-At2Ks-E

Sounds very similar but it also happens below the 5k revs that the video mentioned.
Any idea on how much these cost to fix - if that is the issue?

I haven’t had to deal with this on mine, I’d just looked into all the potential problems that can raise their heads with these cars when buying mine, if it is wastegate rattle then the adjustment is really only a temporary fix and not a permanent solution, here’s a link to replacing the linkage,

https://www.e90post.com/forums/showthread.php?t=1249306

As you still have a warranty you need to get in touch the seller and hopefully if this is the issue then they can get it replaced, certainly get in touch sooner rather than later and make them aware of the issue.
Other potential problems to be aware of with the n54 are high pressure fuel pumps, fuel injectors and water pumps.

 

[IDD]

Hi and welcome to the forum
Sounds like it could be turbo waste gate rattle, see link below

https://youtu.be/JGG-At2Ks-E

Sounds very similar but it also happens below the 5k revs that the video mentioned.
Any idea on how much these cost to fix - if that is the issue?

I haven’t had to deal with this on mine, I’d just looked into all the potential problems that can raise their heads with these cars when buying mine, if it is wastegate rattle then the adjustment is really only a temporary fix and not a permanent solution, here’s a link to replacing the linkage,

https://www.e90post.com/forums/showthread.php?t=1249306

As you still have a warranty you need to get in touch the seller and hopefully if this is the issue then they can get it replaced, certainly get in touch sooner rather than later.

I actually got this wrong... I just checked when I got the car which was the 12/10/21 so I'm pretty sure I'm out of the 3 month warranty by about 2 weeks.

 

[IDD]

Sounds likely, what's the mileage?

Mileage is at 111k currently

Could be why it's not that common on the 35iS then as most cars on here are quite low mileage, doesn't detract from the car though it should give you the same pleasure a a 20k mile car

It would good to feedback on this thread for future knowledge confirming outcome, all too often we read of problems highlighted but no conclusion

Agreed, once I find the issue, I will post an update on it

 

[B21]

FWIW the tuning app MHD has a ‘waste gate rattle fix’ it can apply to the ECU..it takes the slack up in the actuator arms reducing the rattle..

How effective it is especially on a 110k mile car I don’t know.

MHD is not free.