(Power)steering failure

dangerdred · #1 14th October 2022, 11:15 PM

Apologies...it's a little long.
On my way home tonight, I was doing a right-hand turn to merge out onto a dual carriageway, and as I turned to join the initial merging lane, I turned the steering wheel and the next thing the wheel wasn't turning and the car was going to go straight out into the traffic. I braked hard and luckily there was nobody behind me. My power steering was gone completely so with literally all my strength, I managed to turn the steering wheel to straighten the car up and roll it along the merging lane a bit towards the hard shoulder with my hazards on. I killed the ignition and started again but it was still the same. I wasn't far from home but as I started driving down the road all the windows suddenly fogged up as if something was going on with my AC.. On the way, any 90 degree corner I had to take I had to take it really wide, and even still would end up the far side of the road as I came around. Thankfully I got it home in the end and when I turned it off and got out, all the fans under the bonnet were going like billio. I went into the house and came back out 5 minutes later to do a scan. The battery had gone right down with 1 bar on the MMI screen gauge so I thought maybe the fans had depleted the battery. Anyhow, are fans any clue as to what's going on with my steering? When I was doing the scan I inadvertently started the engine, but when I saw it was charging the battery I decided to leave it run. Then I noticed there was a loud whirring sound coming from under the bonnet and when I lifted it, it sounded like a fan was rubbing off something, but as I shone my light in I could see the belt going around and everything looked OK except for the noise. Could it be a seized pulley or something? I'll try and have a better look tomorrow in daylight. Any ideas?

kele · #2 15th October 2022, 07:44 AM

If you have lost all the power steering fluid, you don't want to run the pump without fluid. That would squeal without fluid and fail. I would start by checking the power steering fluid. If low or zero, then look for where the fluid might have leaked. Hopefully it is just a perished hose that you can splice and re-join. Perhaps on the bend behind the fog light position Quite common...

steamship · #3 15th October 2022, 09:40 AM

Check out the following thread. I've linked to a specific post in it which sounds exactly like the problem you have, but worth reading the entire thread after that as several other scenarios are mentioned. As you mention, it could be a seized pulley or tensioner has gone if the belt is still fine:

https://www.audiworld.com/forums/a8-.../#post24766237

dangerdred · #4 16th October 2022, 01:13 PM

It was very hard to see the fluid level so I poured in a little more to see, and it came to the brim almost immediately, so looks like there's no fluid shortage. With the battery having been depleted I took it out and charged it overnight and put it back in the car yesterday without ever switching the car on. I went out today when checking the fluid and turned on the ignition and the battery was again down to one bar? I'm at a loss as to what's draining my battery but does this point to a relay or something electrical?

steamship · #5 16th October 2022, 02:34 PM

If you charged the battery prior to putting it back in the car and never started it, and the MMI now shows just one bar, either the MMI is misleading or something is obviously draining it. That's usually some module that doesn't 'go to sleep' when the car is locked, so best thing is to scan the car and see if you can identify any potential causes (door handles are a prime candidate). Also check module 61 (battery regulator) for errors. Do you have a multi-meter to check the voltage on the battery?

dangerdred · #6 16th October 2022, 03:38 PM

I have a multimeter yes. I went out now to test the voltage on the battery and it's at 12.2V. I got into the car and turned on the ignition and now I see two bars on the MMI!. When I checked the fluid earlier I started the engine for no more than 30 seconds after I saw that the system did indeed have fluid and to check if I still had my PS issue (which I did). If the running engine charged the battery from one to two segments in that short time and now a couple of hours later the two segments (12.2V) are still in the battery then the battery drain must indeed be very slow.
The engine still turns and starts no problem with the battery at one bar on the MMI. but I'm thinking I can't have had this drain all along or my keyless would have stopped working long before now, so I'm al a loss where all of a sudden this battery drain has come from.

I'll need to charge up the battery again before a scan or I'll be getting errors all over the place.