Started car this morning to go to work and all was ok, no faults/problems at all. Started car again a few hours later and when moving off i could hardly turn the steering wheel, it was very heavy and required a lot of effort to turn. I then reversed the car back into my car space and turned off the engine for a few minutes (hoping it would clear any fault upon restarting). When i did restart and attempted to drive/turn i felt a momentary juddering through the steering wheel and have what i can estimate to be 50% of the full power steering back. However its still far off the previous feather light steering that i had when stationary.

Ive used the search facility to familiarise myself with the potential causes but am slightly confused as to why ive only got '50%' of the power steering back. Ive looked at the following;

1) Fuse 15 and 41 - all removed/checked and ok
2) PAS Fluid - light honey colour and at the top mark on dipstick - so all seems ok here
3) Serpentine belt - nice and tight on the pulleys (belt is only 12 months old) - so all ok here
4) PAS Pump - cant see any leaks in this area but i dont know how to test it. Cant really hear it working as engine noise is too loud
5) Servotronic - all wires look connected but i dont know how to test it.
6) BCM - the area around the bcm is bone dry, no evidence of any water ingress......but i dont know how to test this unit.

Another thing ive noted is that i can no longer hear that power assisted hum that you usually get when you turn the steering wheel.

Would any one have an idea as to why ive only got 50% of my power steering back and what the fault could be.

Appreciate all replies!

Mine doesn't make any humming noise when I turn the wheel... maybe yours was telling you something!!!

I'd guess the pump is failing... Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Servotronic is the most likely faulty item and usually the first to be changed

I think I had a similar fault. I was trying to wire in a dash cam, and chose what I thought was a suitable fuse to piggy back from. Got the cam working, but found that steering was then much heavier. Like you thought I had a direct issue, I disconnected it, and problem went.
I can't remember what the fuse was, (in glovebox) but I think I referenced it to the servotronic. So, you might have maybe a blown fuse?
Easy to check too.

John, he said he checked the fuse.... I thought if the servotronic gave up you lost all the assistance... I could be wrong though, mines never had a problem (that's jinxed it) Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Cheers for the comments....

...haylands: the hum/whine noise im referring to is the one you hear on full lock (ive heard it on other RR/7 series BMW too)

....john; ive checked fuses 15 and 41. Are there any others to check?

How do i check/test the PAS pump and servotronic are working before i buy and replace these with new parts.

Is there a component within the steering box/column that could be causing "50%" Power steering loss?

I've a servotronic valve for sale if needed.

UPDATE: Each time the car is started now (after being switched off for a few good hours) i can feel a momentary judder through the steering wheel as i turn it for the first time (when moving off). During this phase (which lasts about 5-10 seconds) the steering is very heavy. It then lightens up slightly to what feels like only 50% power assisted steering.

(However, if the car is re started after a short while , the steering wheel judder doesn't happen).

Any thoughts?

Hi Zane,

I have the excat same problem and I believe that mine started after I changed the auxillary / alternator belt. I will do some research.

regards

John

UPDATE: been driving around with the power steering/juddering problems and then something really odd happened today on start up.......no juddering and it was back to 100% PAS....normal featherlight steering!

Could it have been a mechanical issue like a blockage in the PAS fluid lines/pump having unblocked itself......or an electrical gremlin having corrected itself???

No doubt i'll be back tomorrow complaining its reverted back to heavy steering. These RRs do have a mind of their own!

 All my spelling errorz are belong to me!

2024 RR Velar
2021 AM new Vantage

I had a similar issue of humming noise when turning the wheel

MY Indie said there was a LR service bulletin about it ,
I think he drained fluid and relapsed it with another type ,
they might have replaced a bush in there to.
I could call them and ask about the service bulletin if you wish
let me know

damn spell checker
should have read "replaced"

There is an edit button over here somewhere..................................................................................................^^^^^^^ Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Blackstoun.......that would very much be appreciated if you could.