Good bit of homework if your right, i donât know where the parts are located on the car but if there not that hard to get to it looks like it can be a fairly easy fix if all goes well.
Iâm not a pro but by the sounds of it your rack or pump must be on the way out, thatâs what i was saying earlier about the fluid turning grey, itâs because thereâs metal grinding away in the pump or rack.
Maybe have a good flush through while the parts are off to see if any remaining bits come out where the filter does its job.
Donât take what i say as gospel though; you donât want to damage anything.
Ring a power steering place and ask if they think itâs a good idea.
The PAS pump was replaced under warranty last August due to a squeal on full lock, so I would of thought it was highly unlikely the pump was at fault. The fluid was not in too bad of a condition when I replaced it, just seemed darker than the usual green.
I believe the rack requires removal to remove the solenoid/strainer from the system and I hear this is a pig of a job to do as well.
It would seem to be that this is an electrical issue, not hydraulic. The system physically isn't firing up under load so no matter how much you 'flush' the system, its not going to fix it unless you've got the route key source. You need to know if that solenoid is firing, there's 2 ways of doing this, either check for a voltage over the pins on the plug when the car starts up and runs, the other is to physically feel the valve, a solenoid will make a positive knock when it moves.
Does anyone know what starts the system up? IE are there any other sensors in the system?
The solenoid is definitely firing as after a restart when the engine/fluid is warm the servotronic functions perfectly fine. It is only if I leave the car for a couple of hours and return that it will fail.
Funny you should mention the voltages etc. as last night I performed a few diagnostic tests with a multimeter where the control module (pictured below) sits in the relay junction box.
As I performed these checks after I got home from work last night, the car was warm so the servotronic would function correctly if I was to start it up.
Firstly, I removed the control module and checked for supply voltage to the module on ignition which should have been ~12V. Supply Voltage = ~14.5V
Secondly, I checked the resistance across the pins going to and from the solenoid on the rack. The resistance should have been between 5-20 Ohms. Solenoid Resistance = ~8.2 Ohms.
I also noticed that when starting the car on removal of the control module, the steering would have the same feel as it does with the module normally connected on cold start. I reconnected the module with the engine running (probably not advisable and yes I understand the risks involved in this) and the steering assistance was back again.
I can't really come to conclusion off all of this and perhaps I should try doing the same tests on a cold start condition (perhaps solenoid resistance short circuits or supply voltage isn't available in this condition). It may also be the control module itself at fault, but I can't understand why that would be temperature/condition related as it functions perfectly fine under certain conditions.
Thanks for taking the time to read guys and I really do appreciate your input. Really want to get down to the bottom of this, the worst thing is that I have not yet come across anybody or something online who are in the same situation so it's good to see your interest in this issue.
Thanks again,
Azeem.