Location, location, location

The trials and tribulations of the cars we live with

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Location, location, location

2004 BMW Z4 3.0i Robert Hefferon

WORD ON THE street is that BMW intended the Z4’s convertible roof to be a single unit that dropped straight into the car for assembly, which is all well and good until you hear where the clever chaps decided to tuck the motor and hydraulic pump that power the roof mechanism. I'll spare you any suspense: it’s housed in a ‘waterproof’ casing that sits in the rain channel.

It’s not only rain that washes into the channel but seeds, bugs and general detritus, which all build up and block the rodent-proof grommet. Water fills the void and submerges that ‘waterproof’ housing. About a year ago I had removed the rubber grommet and cleaned the channel but it must have been too late by that point. Once moisture has got inside, the insulating foam saturates and the motor sits there slowly corroding, until one day you hear it take its last breath as you try to close the roof.

I suspected this was the case but the only way to really know was to attempt the tried and tested ‘roof motor relocation’. The pros can get this down to about 45 minutes, despite having to access it from inside the boot, blindly break free zip ties and prise out the housing, while being mindful of the hydraulic hose lines - and all with one hand. It took me a little longer but, once free, it was as I suspected and frankly hoped it would be - soaking wet. Amazingly, after a blast with some WD40 and a couple of days to dry out, it works and now lives tucked into a lovely dry recess in the boot.