Power steering just suddenly

[o2bad455]

Originally Posted by getty150

No codes, no leaks, no whining....just NO Steering.

SYMPTOMS: We just encountered the same loss of steering assist without any warnings or other symptoms on our '08 E83 X3 N52 M-Sport (USA Spec). The power steering (PS) simply stopped assisting after stopping for gas on the way into a congested city, which almost made us overshoot an exit ramp and then made tight curb-side parking unexpectedly challenging. There is no noticeable fluid movement in the reservoir with the engine running, but the belt's good, pulley's not wobbling, no noises or PS leaks.

CONTROLLER?: I thought it might be a steering controller fuse, but fuses 66 and 69 both seem to be fine. Is there any possibility that this could be a controller issue? If I understand correctly, although it seems not to be well documented, the steering controller supposedly actively adjusts the amount of assist. Anyone know if it adjusts to zero assist under any circumstances, even if just in a failure mode? In the meantime, I'll try to get a scan.

RESERVOIR?: I just read that the reservoir has a non-removable filter. If it got plugged somehow, could that cause the issue?

PUMP?: If not the controller or reservoir filter, I guess we'll be ordering a new PS pump. But I've truly never had a hydraulic PS failure anything like this before. It makes me wonder: Are these PS pumps' impellers made of plastic? If so, is there a metal impeller version or upgrade available?

FLUID?: I will say that the fluid had been right at the min mark when cold and about halfway to max mark when hot since we got the X3 a couple of years ago. When on a long trip this past summer, I decided to top it off to full when hot using steering fluid from a small yellow bottle with green label that specifically said it was for BMW. I'll see if I can find the still mostly-full bottle... But perhaps I should have left well-enough alone! After pump replacement, exactly which readily available fluids can we or can we not use?

[RocketyMan]

Originally Posted by o2bad455

SYMPTOMS: We just encountered the same loss of steering assist without any warnings or other symptoms on our '08 E83 X3 N52 M-Sport (USA Spec). The power steering (PS) simply stopped assisting after stopping for gas on the way into a congested city, which almost made us overshoot an exit ramp and then made tight curb-side parking unexpectedly challenging. There is no noticeable fluid movement in the reservoir with the engine running, but the belt's good, pulley's not wobbling, no noises or PS leaks.

CONTROLLER?: I thought it might be a steering controller fuse, but fuses 66 and 69 both seem to be fine. Is there any possibility that this could be a controller issue? If I understand correctly, although it seems not to be well documented, the steering controller supposedly actively adjusts the amount of assist. Anyone know if it adjusts to zero assist under any circumstances, even if just in a failure mode? In the meantime, I'll try to get a scan.

RESERVOIR?: I just read that the reservoir has a non-removable filter. If it got plugged somehow, could that cause the issue?

PUMP?: If not the controller or reservoir filter, I guess we'll be ordering a new PS pump. But I've truly never had a hydraulic PS failure anything like this before. It makes me wonder: Are these PS pumps' impellers made of plastic? If so, is there a metal impeller version or upgrade available?

FLUID?: I will say that the fluid had been right at the min mark when cold and about halfway to max mark when hot since we got the X3 a couple of years ago. When on a long trip this past summer, I decided to top it off to full when hot using steering fluid from a small yellow bottle with green label that specifically said it was for BMW. I'll see if I can find the still mostly-full bottle... But perhaps I should have left well-enough alone! After pump replacement, exactly which readily available fluids can we or can we not use?

I would start a new thread and then just reference this one as it's over a year old. Perhaps those members aren't on the forum as much...