Audi A4 Intermittent Lack of Steering Assistance

[Gundog48]

I have an Audi A4 Quattro B7 2007 and have been suffering with a fault that has developed in the last month or so. It started on a cold morning when I came to pull off the drive and noticed that the steering was very stiff, not like I had lost assistance completely, but more like it was 20% of what it should have been. After driving about 100m to the end of my road, I switched off the engine, fired it up again and it was fine. The fault never happens later in the day despite it being parked for a significant amount of time.

Originally, it only ever happened on cold mornings, however as time went on the fault got worse. It now happens every morning and takes a few miles before it stops. A strange fact I've noticed is that I could drive for 5 miles and the fault would not go away, but I could drive for 3 miles then restart the engine and it will stop, which leads me to believe that it is some kind of electronic fault. But if it was an electronic fault, how would it only occur on mornings? When I say cold weather, I mean around five degrees, no extreme low or sub-zero temperatures.

[jdp1962]

I have an Audi A4 Quattro B7 2007 and have been suffering with a fault that has developed in the last month or so. It started on a cold morning when I came to pull off the drive and noticed that the steering was very stiff, not like I had lost assistance completely, but more like it was 20% of what it should have been. After driving about 100m to the end of my road, I switched off the engine, fired it up again and it was fine. The fault never happens later in the day despite it being parked for a significant amount of time.

Originally, it only ever happened on cold mornings, however as time went on the fault got worse. It now happens every morning and takes a few miles before it stops. A strange fact I've noticed is that I could drive for 5 miles and the fault would not go away, but I could drive for 3 miles then restart the engine and it will stop, which leads me to believe that it is some kind of electronic fault. But if it was an electronic fault, how would it only occur on mornings? When I say cold weather, I mean around five degrees, no extreme low or sub-zero temperatures.

Firstly, welcome to the forum.

Niceties over, let's start with the basics; have you checked the level in the power steering fluid reservoir? Are there any signs of leaks? Any signs of the power steering drive belt needing attention?

[Gundog48]

Firstly, welcome to the forum.

Niceties over, let's start with the basics; have you checked the level in the power steering fluid reservoir? Are there any signs of leaks? Any signs of the power steering drive belt needing attention?

Thanks for the welcome! I'm an engineer myself, but this is baffling me! I've checked the basics- fluid is fine- no sign of leaks, and no sign of the belt slipping. By the way, this is a 2.0T FSI. Out of interest, does an ECU control the mechanics of the steering rack?

[jdp1962]

Thanks for the welcome! I'm an engineer myself, but this is baffling me! I've checked the basics- fluid is fine- no sign of leaks, and no sign of the belt slipping. By the way, this is a 2.0T FSI. Out of interest, does an ECU control the mechanics of the steering rack?

Ok, apologies for trying to teach grandma to suck eggs!! I am about as far as it is possible to be from being an engineer.

The only other thing that comes to mind is that if yours has the same steering setup as mine (I have a 57-reg 3.0TDi Quattro), it is the variable assistance "servotronic" system. I've no idea how this works, but maybe whatever controls it (electronic, hydraulic, maybe a combination of the two) is malfunctioning.

Sorry for being no help whatsover. With any luck, someone who knows what they're talking about will be along soon.