Two main issues in my new Z4. Please help

[3k1m]

Hello everyone!

I bought recently '03 e85 which (I hope) has two main issues.

First)

Power steering above 10 mph becomes harder to turn and steering wheel always keep a little bit to the left, especially on uneven road. Feels like tramlining. When moving slowly, parking, reversing power steering seems alright. Tyres pressure is correct

Two)

When pressed to drop the roof, windows rolled down, roof moved few centimetres and that's it. I could still hear back motor working but not moving. Worst thing: I put it down manually and could not lift it even by following manual procedure!! Pulled and usecured that red thing in the boot and it was so hard to lift it manually that I almost gave up. Felt like I was lifting 100 kg and eventually lift it up and close it. Day before I disconnected battery for a while but I am not sure if it could be an issue. Also boot shelf was dropped down as it supposed to be. No idea what's going on.

[Number5]

Where are you based?
I may be able to help with the roof issue. Ideally you want the motor relocated into the boot (which I can do) then it’s easy to diagnose and resolve.

[Roberltd2]

Bear in mind that the power steering is designed to have a smaller effect as the speed increases I think I'm right in saying.

[Zulu4]

First issue could be the infamous "sticky steering".
viewtopic.php?t=100725

[zriha]

When pressed to drop the roof, windows rolled down, roof moved few centimetres and that's it. I could still hear back motor working but not moving. Worst thing: I put it down manually and could not lift it even by following manual procedure!! Pulled and usecured that red thing in the boot and it was so hard to lift it manually that I almost gave up. Felt like I was lifting 100 kg and eventually lift it up and close it. Day before I disconnected battery for a while but I am not sure if it could be an issue. Also boot shelf was dropped down as it supposed to be. No idea what's going on.

Sound to me like the problem of the wires. You have a bundle of wires coming from the motor in the boot to the motor on the top (that releases the hooks). As I drive left-hand car, my wires are just above my driving seat. Yours could be then above co-driver's seat.

Try to touch them with your hands above your head, you can easily and carefully stick your fingers between the roof and the interior lining. Then, when you find them, try to put your roof down, when the procedure starts and stops, dangle those wires while still pressing the button, if the roof moves, you have a wires problem.

That's relatively easy to fix, I was to lazy still to do it, but you can basically rewire everything, and give more protection to the wires. As with the time, and opening/closing of the roof, wires can have breaks and small shortages in connection emerge.

[Jamesbradbury]

Just checking you don't have runflats, s**t steering especially along bad roads is very often them.

[Street]

Roof issue:
If you can hear the motor running in the boot you don’t have any broken cables as previously suggested.
It’s more likely that the pump bypass valve is stuck.

The red pull handle is connected to a Bowden cable. This cable levers a brass switch on the pump.
It twists flat to the boot roof and pushes in to ‘enable the pump’. Pull out and twist to keep it out to disable.

If pushed in and it still doesn’t work, you need to get to that pump (might as well relocate it while there) and check it.

There is a pic at the bottom of this thread: viewtopic.php?t=132420