Unstable at 50+, sluggish and heavy at low speeds

[Zukunft501]

Hi,

Apologies if this has already been covered and I've missed the thread.

I've recently changed all tyres ( rear two first and front a month later) Driving and steering at low speeds (under 40mph)became heavy, as if i was partially braking thus requiring more revs to get going. On reaching motorway speeds theres a deep thud similar to that of a flat tyre, some shaking in the cabin.

All tyre pressures are as they should be, I've also had all wheels balanced. Following balancing the car drives as should but then the issue returned after a few miles, sluggish heavy and thuds at higher speeds. Also a lot more fuel is being consumed.

Has anyone encountered this issue previously?

 

[mr wilks]

What tyres ?
Are they fitted the correct way ?
Has the car had a alignment recently ?
Any idea when front control arms were replaced ( if at all )

 

[Zukunft501]

Hi,

Car was aligned 12 months ago,
I did have the n/s/f control arm replaced 2 years ago.

As for the tyres I can only assume they were installed correctly as initially driving on them was fine. fronts are 225/40R18 rears 255/35R18 . all run flats.

 

[enuff_zed]

Brakes binding?

 

[mr wilks]

Have you felt all 4 brake calipers for excessive heat after a drive which included spells of braking ?

 

[Zukunft501]

I've not felt the callipers yet, but I'll give it a try. Thanks for the suggestion.

 

[RKM]

Get an infrared heat sensor, very inexpensive, to measure brake temps.

 

[enuff_zed]

Get an infrared heat sensor, very inexpensive, to measure brake temps.

Or an inaglove heat sensor, very inexpensive, one on the end of each arm

 

[Crazy Harry]

Saw the title and thought - yea I'm getting like that. This growing old thing is pants :lol:

Having said that the E85/86 are getting a bit old in the tooth now think the youngest are 10 or 11 and chances are the pads and discs may have been done a couple of times but not the pins. It might be worth changing the slider pins and getting a good lump of red brake grease in the rubber selves. Not a long or difficult job and the only 'special' tool is a 7mm (IIRC) hex key socket or alan key - which you may have already.

pins on ebay
https://www.ebay.co.uk/itm/FRONT-BRAKE-CALIPER-SLIDER-PIN-GUIDE-KIT-FITS-BMW-Z4-E89-2009-EUK1306/383351469469?hash=item594187359d:g:xlwAAOSwBoxeB-tX

and
https://www.ebay.co.uk/itm/BMW-Z4-E85-E86-2003-2009-REAR-CALIPER-SLIDER-PIN-GUIDE-BOLT-KITS-EUK1306X2/383351473914?hash=item59418746fa:g:I50AAOSwf1leB-tc

and the hex key
https://www.halfords.com/workshop-tools/tools/sockets-accessories/halfords-advanced-hexagon-bit-socket-7mm-3-8-drive

 

[firebobby]

Did you have run flat tyres fitted ?

 

[sw4nny]

Hi,

Apologies if this has already been covered and I've missed the thread.

I've recently changed all tyres ( rear two first and front a month later) Driving and steering at low speeds (under 40mph)became heavy, as if i was partially braking thus requiring more revs to get going. On reaching motorway speeds theres a deep thud similar to that of a flat tyre, some shaking in the cabin.

All tyre pressures are as they should be, I've also had all wheels balanced. Following balancing the car drives as should but then the issue returned after a few miles, sluggish heavy and thuds at higher speeds. Also a lot more fuel is being consumed.

Has anyone encountered this issue previously?

Just had a similar issue.
Turned out to be a knacked front off side caliper i ended up having to replace this.
As said above tell tale signs hot disc and smell of burning,
The symptoms got worse as the brakes heated after binding usually after doing around 5 miles from cold start,mine also felt sluggish,you could try getting the brakes hot, put your car on a very slight gradient and if the car does not roll freely then this could another sign of sticking caliper

 

[Zukunft501]

Just had a similar issue.
Turned out to be a knacked front off side caliper i ended up having to replace this.
As said above tell tale signs hot disc and smell of burning,
The symptoms got worse as the brakes heated after binding usually after doing around 5 miles from cold start,mine also felt sluggish,you could try getting the brakes hot, put your car on a very slight gradient and if the car does not roll freely then this could another sign of sticking caliper
[/quote]


That makes sense, as after id had the wheels balanced, the car was fine for a few miles and then the problem started again.


Thanks for all of the replies and advice everyone. She's booked in and will hopefully be back on the road again soon.

 

[wonkydonkey]

Thanks for all of the replies and advice everyone. She's booked in and will hopefully be back on the road again soon.

Did you feel your wheels/brakes to check for any heat differences though? This was going to be my suggestion also.

 

[Zukunft501]

Front passenger side was a lot hotter than the others, she's in being checked as I type.