The E85 Z4 Roof Motor problem is well know now seeing as the earliest Z4’s (2003) are almost 13 years old.
The Roof Drain’s get blocked with leaf matter, general roof moss, and atmospheric dirt which washes off the roof into the drain pockets.
Then the drain pockets fill up and submerge the electric Roof Motor in water, as well as cause corrosion issues on the Hydraulic Pipes.
When the drain pockets get full of water, it overflows into the chassis members behind the seat & seat belt area’s. This water then makes it way into the cabin and runs over the Airbag Satellite B-Pillar Modules, as well as wet the carpets behind the seats.
The water can also accumulate inside the Sill’s and sometimes at low speed be heard ‘sloshing’ backwards and forward until a plastic jacking pad is removed to let the trapped water escape.
If you cannot clear the blocked roof drains with compressed air, rods, or borescope camera/equipment, then it’s best to remove the Roof assembly where a screwdriver is usually required to break through the blockage and allow water to escape (then test with a hose to make sure the drains are flowing water underneath the car in front of the rear wheels.
If your Z4 Roof has stopped working, or making a spitting/fluid noise and clear oil is found near the roof, then it’s likely the Roof Motor has failed, or a Hydraulic Pipe has ruptured (both due to water corrosion).
These parts are all available from your BMW Dealer, and most garages, and BMW Specialists, and Main Dealers will be able to carry out the repair.
If you have Z4 Roof problems, and need us to look at the issue, please call into our workshop in Bristol, or call to make an appointment on 01179 781889.
“Specialists for BMW Vehicles”