Help. S.O.S. Bizzare Power Steering failure - Resolved

[Audioslave686]

I had an unfortunate accident at VIR some time ago. Bumper and some suspension damage. Not too bad, given the circumstances.

Immediately after the accident, the power steering stopped working.
It looked like a PS pump failure as the power steering pump was overheating and making a grinding noise.
After getting home, I also noticed the Servotronic wiring got damaged by the wheel (picture attached).

I replaced the PS pump, bled the system, soldered in the new piece of wire, and checked all the steering-related fuses. – No change.
No power steering, the new pump starts to overheat after about 20-30 sec on idle.

Looks like a blockage in the system, but the fluid flows all right when the engine is off.

Next step I replaced all the ps hoses. No change.
Used this opportunity to upgrade the PS cooler to Do88. Again, no change.

I got my hands on a used steering rack.
I tried to replace the Servotronic solenoid separately, no change.
I replaced the whole steering rack with the solenoid, no change as well.
Double-checked the wiring to make sure I did not mess anything up. Everything looks good.

Now I have a whole new power steering system except the steering rack, that still does not work.
At this point, it looks like an electrical issue. However, I’m not receiving any steering-related codes.
The only codes I see are:
A6CF – AUC sensor
A8C5 – headlight related.

Has anyone experienced anything similar?

I’m looking for ideas on what else should I check.
Any advice is greatly appreciated.

[amrazM]

you bought a brand new pump? is the belt routed the right way? there may be initialization in ista for AFS on the e90, I havent used it before but the AFS initialization is there for other cars. the steering rack you purchased did not come out of a crashed car I presume? is your power steering not working at all?

[Audioslave686]

Originally Posted by amrazM

you bought a brand new pump? is the belt routed the right way? there may be initialization in ista for AFS on the e90, I haven't used it before but the AFS initialization is there for other cars. the steering rack you purchased did not come out of a crashed car I presume? is your power steering not working at all?

yes, the PS pump is new as well as the rest of the system, including the PS reservoir. the belt is fine, I double-checked it at one point.
the steering rack - I reinstalled the original as it looks completely fine and acts exactly the same as the other one.

The power steering is not working at all. not even a bit...
i got zero improvement vs how if felt right after the accident.

that's why I'm leaning towards something electrical. Thank you for the hint of AFS initialization.

[RocketyMan]

Reading through the post...I didn't see much mention about checking the bajo bolt with the check valve. It is possible that the check valve is not performing appropriately.

If it was "electrical," then all it would be doing is allowing the line pressure to vent off. This would effectively just give little steering assist but allowing the line pressure to return to the reservoir.

Here is the bajo bolt with check valve.
https://www.realoem.com/bmw/enUS/par...&q=32416781261

17 Banjo bolt with check valve M14X1,5X27,4 1 32416781261 $10.02


As a side note, AmrazM is correct about the PS pump itself. There is a superseded pump that spins "opposite" direction. You need to verify by P/N the correct one as the belt routing is in fact different.

What P/N is your old, ORIGINAL pump vs the new replacement part?

[Audioslave686]

great point on banjo bolt. i'll swap both just to be safe. thank you!

i returned the old pump as a core so, won't be able to double-check the P/N,
the new P/N is the same as realOEM and the pump performance did not change to worse (if it is even possible in my case...)

[RocketyMan]

Originally Posted by Audioslave686

great point on banjo bolt. i'll swap both just to be safe. thank you!

i returned the old pump as a core so, won't be able to double-check the P/N,
the new P/N is the same as realOEM and the pump performance did not change to worse (if it is even possible in my case...)

You have to understand (more like interpret) tho what realOEM has in its description of the listed P/Ns.
For instance, you need to confirm the P/N in this case because it could be a counterclockwise pump and your vehicle is configured for clockwise.

I guess the next step would be to confirm your accessory belt configuration. Do you have a clockwise or counterclockwise configuration? Do you have a picture? Then...what pump P/N exactly are you putting in?

P.S. The banjo bolts are two different sizes, and only ONE has the check valve. So there's no point to replace both.

[Audioslave686]

Originally Posted by RocketyMan

You have to understand (more like interpret) tho what realOEM has in its description of the listed P/Ns.
For instance, you need to confirm the P/N in this case because it could be a counterclockwise pump and your vehicle is configured for clockwise.

I guess the next step would be to confirm your accessory belt configuration. Do you have a clockwise or counterclockwise configuration? Do you have a picture? Then...what pump P/N exactly are you putting in?

P.S. The banjo bolts are two different sizes, and only ONE has the check valve. So there's no point to replace both.

the car's production date is 10/10
here is the pump i installed
https://www.fcpeuro.com/products/bmw...zf-32412283002
same part number as per realOEM.

already ordered the banjo bolt. i really hope it is my issue...

[bigjae1976]

I was going to say banjo bolt w/ check valve. Its a ball check in a relatively fragile housing. Could have be damaged some how which wouldn't necessarily be noticable unless you really looked at it.

[RocketyMan]

Originally Posted by Audioslave686

the car's production date is 10/10
here is the pump i installed
https://www.fcpeuro.com/products/bmw...zf-32412283002
same part number as per realOEM.

already ordered the banjo bolt. i really hope it is my issue...

Okay. As per your vehicle's production date, then it would be correct to have the couterclockwise pump like the replacement you ordered.

Let us know of any update you find on your banjo bolt with the check valve.

[Audioslave686]

Originally Posted by RocketyMan

Okay. As per your vehicle's production date, then it would be correct to have the couterclockwise pump like the replacement you ordered.

Let us know of any update you find on your banjo bolt with the check valve.

i definitely will.
fingers crossed

[Audioslave686]

it was a freaking banjo bolt!!!

RocketyMan, i owe you a drink!

pictures of the failed banjo bolt.
the ball should not stick out that much...

[RocketyMan]

Awesome!! Thanks so much for reporting back with pictures. This is very helpful for anyone perhaps experiencing the same problem.

[Audioslave686]

Originally Posted by RocketyMan

Awesome!! Thanks so much for reporting back with pictures. This is very helpful for anyone perhaps experiencing the same problem.

yup, cause no way i would catch that without comparing to the good banjo bolt side by side

[bigjae1976]

Originally Posted by Audioslave686

it was a freaking banjo bolt!!!

RocketyMan, i owe you a drink!

pictures of the failed banjo bolt.
the ball should not stick out that much...

Attachment 3303075

Attachment 3303076

Dam...that's the second one I've seen this month. I saw one on an E46 M3. Glad you got it fixed. I'm pretty sure this was causing a couple of other people headaches too.