35is knocking from front when cold

[jonkoxe11]

Hi all
A bit of a strange one for you.
After the car has sat for a while, at least 12 hours, when I drive away I get a distinct knocking / looseness from the front. I would normally put this down to worn anti roll bar bushes or drop links. However, after about half a mile it goes away. It is if something warms up or some slack somewhere is taken up.
It only happens after the car has sat for at least 12 hours.
As mine is a 35iS I am thinking it might be the adaptive suspension but before I go replacing a load of stuff I thought I would ask.

Thank you.

 

[B21]

Could be anything in the suspension system but does sound more to do with the shock absorber…

I had something similar which was attributed to some worn damper bushes..

The reason this appears when the car is cold is the damper oil is cold and transmits a bit of extra stiction to any rogue bush etc..once the dampers have moved around a bit the oil inside thrn is warm and the damping effect on stutter bumps etc is more muted..

That’s what the Ohlins guy said..

 

[Pondrew]

That’s what the Ohlins guy said..

I'm amazed he could speak English TBH. :roll:

 

[jonkoxe11]

Could be anything in the suspension system but does sound more to do with the shock absorber…

I had something similar which was attributed to some worn damper bushes..

The reason this appears when the car is cold is the damper oil is cold and transmits a bit of extra stiction to any rogue bush etc..once the dampers have moved around a bit the oil inside thrn is warm and the damping effect on stutter bumps etc is more muted..

That’s what the Ohlins guy said..

Thank you for this info. Makes sense. I will start the process of eliminating the easy (cheap) bits first before I face the replacement struts issue. Where do we go for good quality bushes etc? I am new to BMW ownership so unfamiliar with the aftermarket suppliers network

 

[B21]

Lemforder, Meyle HD, TRW are tier 1 suppliers…Autodoc is a general go to company for BMW quality parts…

There are other suppliers often very good but with maybe NVH trade offs

 

[flybobbie]

My car has weird noise from the front when the weather is warm around 25 degrees going over speed humps.
Sounds like a rubber bush twisting.
Same every year when weathers warm.
Could never pin down the cause.

 

[jonkoxe11]

Update. I took the car for it's annual MOT and it has failed on the shock absorbers. Leaking oil badly. I am fighting with the warranty company at the moment to pay up for replacements (RAC Warranty from the dealer appears worthless). As I feel no matter how much screaming and shouting I do it will be up to me to pay. So, there appears to be a large cost differential between those chinese suppliers and BMW direct with AeroSUS sitting somewhere in the middle.
So my ask is. How do I beat the RAC into paying. Then if not possible, where to get the new shocks?
Thank you

 

[B21]

If I was in the market for replacement adjustable dampers I'd go with the Aerosus assuming at least a year warranty..they MAY be a German front end to Chinese products but I wouldn't entertain the risk of going direct..

I see the rears are out of stock with no delivery date..

 

[Deepseaskateboard]

Update. I took the car for it's annual MOT and it has failed on the shock absorbers. Leaking oil badly. I am fighting with the warranty company at the moment to pay up for replacements (RAC Warranty from the dealer appears worthless). As I feel no matter how much screaming and shouting I do it will be up to me to pay. So, there appears to be a large cost differential between those chinese suppliers and BMW direct with AeroSUS sitting somewhere in the middle.
So my ask is. How do I beat the RAC into paying. Then if not possible, where to get the new shocks?
Thank you

Warranty disagreements usually involve reading the terms and conditions you signed and see if you are covered for these.

If you think you have a case, you can show them the contract wording, if they disagree and you still think you are right you will have to use the ombudsman or similar.

Car warranties are usually pretty air tight.

Good news is, you should be able to get them refurbed somewhere in europe, lots of posts on here about a company which refurbs them.

 

[jonkoxe11]

Latest update.
Totally failed to get warranty to pay up. Every time I caught them out they just changed their response to something else. Utterly useless.

So..... I bit the bullet and got on with the job in hand. Replace both front shocks as cheaply as possible. After some research it would appear that Aerosus is a German / Euro front for the same Chinese parts listed on eBay. So I took a punt on a pair that was from a new seller that could ship from a UK warehouse. They arrived in a couple of days and on inspection seemed well made. Like most pattern parts they are not quite right so a little fettling was needed on the lower spring plate to get the rubber to fit correctly.
Also from eBay I purchased new top and bottom rubbers, dust gaiter, spring plate and top mount. Could not find bump stops so reused existing which were in good condition.
Replaced drop links from GSF while I was at it.
Amazon provided the necessary tools, spring compressor and hub spreader.
Job was fairly straight forward, took me about 8 hours to do both sides. Spring compressors are terrifying to say the least. Passed the MOT and now back on the road. Happy days.
All in I spent £300 for everything. I suspect the Chinese Shocks will need doing again in a few years but you know what they say, buy cheap, buy twice.... :rofl: BMW wanted £750 per side so I can do it 5 times and still be quids in.

Sorry no photos. It was p**sing with rain and cold so I was not in the mood....

Some links for reference if anyone else in need:
https://www.ebay.co.uk/itm/315907206919
https://www.ebay.co.uk/itm/315839339283
https://www.ebay.co.uk/itm/174796904583
https://www.ebay.co.uk/itm/194194813507
https://www.ebay.co.uk/itm/184878514299
https://www.ebay.co.uk/itm/185591945986
https://www.amazon.co.uk/dp/B008LL2ECW?ref=ppx_pop_dt_b_product_details&th=1
https://www.amazon.co.uk/dp/B0D1K7G8KR?psc=1&ref=ppx_pop_dt_b_product_details
https://www.gsfcarparts.com/products/droplink-stabiliser-front-lh-za048173
https://www.gsfcarparts.com/products/droplink-stabiliser-front-rh-za048174

 

[B21]

Latest update.
Totally failed to get warranty to pay up. Every time I caught them out they just changed their response to something else. Utterly useless.

So..... I bit the bullet and got on with the job in hand. Replace both front shocks as cheaply as possible. After some research it would appear that Aerosus is a German / Euro front for the same Chinese parts listed on eBay. So I took a punt on a pair that was from a new seller that could ship from a UK warehouse. They arrived in a couple of days and on inspection seemed well made. Like most pattern parts they are not quite right so a little fettling was needed on the lower spring plate to get the rubber to fit correctly.
Also from eBay I purchased new top and bottom rubbers, dust gaiter, spring plate and top mount. Could not find bump stops so reused existing which were in good condition.
Replaced drop links from GSF while I was at it.
Amazon provided the necessary tools, spring compressor and hub spreader.
Job was fairly straight forward, took me about 8 hours to do both sides. Spring compressors are terrifying to say the least. Passed the MOT and now back on the road. Happy days.
All in I spent £300 for everything. I suspect the Chinese Shocks will need doing again in a few years but you know what they say, buy cheap, buy twice.... :rofl: BMW wanted £750 per side so I can do it 5 times and still be quids in.

Sorry no photos. It was p**sing with rain and cold so I was not in the mood....

Some links for reference if anyone else in need:
https://www.ebay.co.uk/itm/315907206919
https://www.ebay.co.uk/itm/315839339283
https://www.ebay.co.uk/itm/174796904583
https://www.ebay.co.uk/itm/194194813507
https://www.ebay.co.uk/itm/184878514299
https://www.ebay.co.uk/itm/185591945986
https://www.amazon.co.uk/dp/B008LL2ECW?ref=ppx_pop_dt_b_product_details&th=1
https://www.amazon.co.uk/dp/B0D1K7G8KR?psc=1&ref=ppx_pop_dt_b_product_details
https://www.gsfcarparts.com/products/droplink-stabiliser-front-lh-za048173
https://www.gsfcarparts.com/products/droplink-stabiliser-front-rh-za048174

Thnx for the write up and the deep dive