2004 e85 soft top issues

[tomjonesBT33]

Folks - new Z4 owner here. Acquired from my brother in law who is in the Air Force and stationed overseas. It's a project car. It's been sitting outside for a couple of years. 215K miles. Body and drive train are in good order but there are quite a few electrical gremlins that I'm trying to work through.

I've been going through the car to clean it thoroughly. I've discovered a few mice nests as a result of it being parked for a couple of years. One issue that just cropped up is the soft top has started acting up. I've searched but been unable to find any posts that talk about the issue that my car is experiencing. I was removing the truck liners to clean out under, behind, etc. I found this:

Before



After


This is the rear wall in the trunk on the left side just behind the driver's seat (US spec LHD). I cleaned this up. Now the top is not working correctly. I may have disturbed an electrical connection or it may just be coincidence - I dont know. But the symptoms are strange. I press the open (or close) button for the top and it moves an inch or so then stops. Release button, wait a second or two and then press again and it moves another inch or so then stops. Etc. I can open or close the top this way but have to repeat the press, hold, release, wait, press process many many times. If I try pressing the button, holding until the top moves an inch then stops, release and press again without waiting a couple of seconds, the top does not move. It almost seems as if something is heating up and trips a temp circuit that causes the motor to stop working. Then if I wait a couple of seconds it cools enough that pressing the button makes the top move again briefly.

I've had the car a couple weeks now and the top had been working fine until this. Any thoughts? Any way that I can power the motor directly to rule in/out a motor issue?

Thanks for any advice.

 

[tomjonesBT33]

UPDATE:

I read/reset the error codes in INPA. Nothing related to the CVM convertible top ECU. But after that, I was able to automatically lower the top though it was slower than usual. However the top will not automatically close. The motor runs but does not lift the top back into a closed position. Sounds like the hydraulics are not building pressure? Again, is there a way to test the motor independently of the circuits, eg directly applying 12V, etc? Or can the hydraulic system be bleed and replenished with new fluid?

 

[srhutch]

Sounds like you have the usual issue with the roof. Common problem. The motor is probably submerged in water.

It can easily be removed and relocated into the boot after cleaning the motor out in diesel or similar.

Tons of info on here. If you were in the UK there are 3 or 4 people that do the job for around £150.

 

[ph001]

Also, if you have the motor running but without much movement of the hood, this is almost certainly because the brass bypass plunger on the motor is stuck in (it is activated by the bowden cable with the little red handle on in the boot). Either way, you need to pull the motor through into the boot to free it up.

 

[tomjonesBT33]

the brass bypass plunger on the motor is stuck in (it is activated by the bowden cable with the little red handle on in the boot).

This makes sense. If the cable is stuck in the partially ‘manual’ state then it would not allow hydro pressure to build in the pump. I’ve pulled the red handle a few times so far to manually open/close the top when I’ve had the battery disconnected. The cable does not slide freely. There is no solid feel or tactile feedback to the cable movement.