Doors

Doors

Due to the body design of each E30 model, doors are not generally compatible between different models. However, doors from identical models of different ages are also interchangeable, but attention needs to be paid to the internal mechanisms, including the wiring loom and window mechanisms.

The front doors of each E30 are model specific, and therefore cannot be interchanged. For example, those fitted to a 2-door are too long to fit a 4-door, while Cabriolet doors lack the window frames needed for a 2-door. However, front doors of a 4-door are interchangeable with a Touring.

The rear doors of 4-door models and Touring models are not interchangeable due to the differing shape of the window frames. However, interior window mechanisms and all interior trim including door cards and handles are interchangeable between the two models.

Learn more about removing and replacing doors

Components

Windows

Pre-facelift electric window mechanism

The internal window mechanisms changed during the facelift, meaning cars up to and including 1987 models have different glass, mechanisms, looms and motors (if fitted) compared to 1988 and later cars. This means that if you are considering installing electric windows to your vehicle, it is important to have the correct mechanism and loom for your model.

Facelift electric window mechanism

If you are planning on installing rear electric windows to your car, be aware that the appropriate wiring for the loom is installed. Look on the B-pillar of your car and locate the small plastic removable panel; inside this should be the plug to which you will connect the door loom when required.

Learn more about retrofitting electric windows.

Wing Mirrors

Wing mirrors are interchangeable across the entire E30 range.

The wing mirrors are electrically operated by a thumb switch on the driver's armrest, mounted to the door card. Power is given by the loom to a motor inside the wing mirrors which controls horizontal and vertical tilt. Some mirrors were fitted with a heating element, but this is automatically controlled and requires no switching by the driver.

The wing mirrors are mounted directly to the door frame using two 8mm bolts. To access them, use a flat bladed screw driver to gently prise off the plastic trim triangle from inside the door. Unplug the four-pin socket, then hold the mirror while loosening the bolts.

Locks

E30 locks are a very simple barrel design, and can be removed, dismantled, repaired or recoded fairly simply. They are held in place with a C-shaped clip what presses the lock barrel against the inside of the door skin. This clip can be pulled sideways and removed with a long screwdriver and some nimble fingers, after removing the door card.

If there is a problem with your locks, learn more about repairing your door locks. Main article: Central Locking

Electrics

All electric elements of the door are controlled by a one-piece loom, which connects to a plug in the A-pillar (front doors) or B-pillar (rear doors). The loom plugs are different between pre- and facelift cars, but the essential wiring is the same. From the plug, the loom provides power and control to the:

• Door locks
• Door lock heater (if fitted)
• Wing mirrors
• Electric windows (if fitted)

The door pin switch, which senses the opening or closing of the door, is separate from the door loom.

Trim

The two main trim elements of the door are the weather seal, which seals the gap between the door and window, and the bump trim, which runs along the middle of the panel.

To remove the weather strip, simply lower the window and use a flat screw driver to prise the weather strip upwards, being careful not to bend it.

To remove the bump trim, remove the 10mm plastic screw from the door jamb and then pull the strip firmly away from the door. It is held on with two plastic clips, which can only be removed from inside.

Common Problems

Rust

Due to the nature of the door skin, most E30 doors develop rust along their bottom edge, despite the seam sealer applied there by BMW. Surface rust can be rubbed down, filled and repainted, but more serious rot requires the door to be reskinned properly.

Sticky Windows

The glass for the windows is raised and lowered by a simple mechanism bolted to the bottom edge of the glass. The sides of the glass then run in two channels, which can accumulate dirt and debris which will affect your windows. If your windows are not raising and lowering probably, learn more about adjusting your front windows.

Electric Windows not working

The electric windows fitted to E30s are a simple mechanism involving a cable and winch system (pre-facelift) or a scissor-jack mechanism (facelift), driven by an electric motor. If unused, these electric motors can become rusty inside causing them to seize up. However, the most common fault of electric windows is simply dirty switches.

To troubleshoot, use a flat screwdriver to prise up two window switches from the centre console, and swap them over. Now test the windows. If they work, the fault is the switch, which is usually dirty contacts. These can be cleaned up with sandpaper and Contact Cleaner spray.

If none of your electric windows work, check the fuse. If your electric windows only work with the door open, but not with the ignition on, then the fault lies in the switching mechanism that diverts power from the ACC (accessories) to the IGN (ignition) circuit, and is governed by a small blue relay under the dashboard.