BMW X5 E53 3.0d FL - Steering very heavy, despite almost everything new (comparison vehicle available)

[TheGermanGuyNr1]

Hello everyone,

I need your advice because I’m slowly running out of ideas with my E53’s steering.
(I’m from Germany so i used Google Translate for some Parts)

Vehicle:
• BMW X5 E53 3.0d Facelift
• Same wheel/tire combination as comparison X5
• Wheel alignment done on both vehicles, values according to workshop are OK
Symptom:
• Steering significantly heavier than another E53 3.0d FL that I can directly compare (same equipment, same wheels)
• Centering/return is equally good on both cars - even after cornering, no “sticking” or pulling
• No noises, no clunking, no vibrations
• When lifted (front axle raised), my X5 steers significantly lighter; on the ground it’s heavy again
Already replaced/checked:
• Steering rack new (hardly any difference before/after)
• Power steering pump new
• Power steering fluid + flushing new
• Servotronic valve on steering rack new (no difference)
• Steering column universal joint new and correctly installed
• Tie rod ends checked (supposedly OK)
• Sway bars new
• Steering column inner transition lightly treated with silicone/penetrating oil (only minimal subjective improvement)
Servotronic/Electrical:
• Read out with diagnostics: Servotronic values/status in control unit 1:1 identical on both X5s
• Servotronic connector unplugged → steering becomes even heavier on my X5 than with connector plugged in

→ Servotronic is basically working, so it’s not completely dead
• No relevant fault stored in control unit
Comparison to the other X5:
• Same wheels/tires, similar equipment
• Return behavior of both vehicles practically identical; mine possibly even slightly slower
• BUT: The other X5 feels 2-3x easier to steer, especially when maneuvering and in city traffic

I don’t know what else to do. No one could help me further. Not even professional BMW workshops.
Thank you in advance

[LOW4LYF]

Have you tried to recode the GM Module or replacing the Servotronic Sensor?

[ptpending]

unless the replaced parts are from bmw, they can be not working even if they are "new"
there is no servotronic sensor here, only valve which is controlled by GM module if servotronic option is coded
so i would test what voltage is applied to this valve on both cars
and also would try to measure steering fluid pressure on both cars
if this not possible, the other way is to swap parts by part to another car to see if something changes
steering pump
steering rack
gm5 module
and of course i'd check the option list for both E53 to be sure that both cars have servotronic

[TheGermanGuyNr1]

Originally Posted by ptpending

unless the replaced parts are from bmw, they can be not working even if they are "new"
there is no servotronic sensor here, only valve which is controlled by GM module if servotronic option is coded
so i would test what voltage is applied to this valve on both cars
and also would try to measure steering fluid pressure on both cars
if this not possible, the other way is to swap parts by part to another car to see if something changes
steering pump
steering rack
gm5 module
and of course i'd check the option list for both E53 to be sure that both cars have servotronic

Hey, Everthing has been replaced with original parts. I know that it’s only a vale. The valve has been replaced. I used INPA to see how the Servotronic is working and turns out both cars get the same 700mA and 40% PWM. Both cars have servotronic.

[TheGermanGuyNr1]

Originally Posted by LOW4LYF

Have you tried to recode the GM Module or replacing the Servotronic Sensor?

I used INPA and saw that both cars have the same live values for servotronic. By sensor you mean the vale probably, yes it’s new.

[ptpending]

Originally Posted by TheGermanGuyNr1

Hey, Everthing has been replaced with original parts. I know that it’s only a vale. The valve has been replaced. I used INPA to see how the Servotronic is working and turns out both cars get the same 700mA and 40% PWM. Both cars have servotronic.

i understand
but you need to measure at plugs, using the piercing measuring plugs
and measure the pressure which pump produce