How To Replace Your E90 Door Lock Cylinder Retaining Screw

The E90 door lock cylinder retaining screw is a 4mm screw that is used to secure the lock cylinder in place on BMW E90, E91, E92, and E93 3-Series models. The lock cylinder can wear out over time and become stiff, leading to handle malfunction. Replacing the lock cylinder is a relatively easy process, requiring only a few tools and steps. Repair kits are readily available for purchase, and the repair process typically involves loosening the retaining screw with a 4mm Allen bit, sliding out the old lock cylinder, and installing the new one.

Replacing the lock cylinder on a BMW E90

Overview:

The lock cylinder in your BMW E90 can wear out over time, causing the door handle to malfunction. Replacing it is a fairly straightforward process and can be done in a few simple steps. Here's a guide to help you through the process.

Tools and Parts Required:

• Plastic prying tool
• 4mm Allen bit
• Flathead and Phillips screwdrivers
• New lock cylinder
• Door panel trim clips (optional)

Step-by-Step Guide:

Step 1: Using a plastic prying tool, gently remove the rubber plug covering the lock cylinder.

Step 2: Loosen the lock cylinder fastener using a 4mm Allen bit. Turn it until it disengages from the door lock. Do not remove the fastener completely.

Step 3: Slide the lock cylinder out of the door. If it doesn't come out easily, use the plastic prying tool to gently lever it out.

Step 4: Install the new lock cylinder by sliding it into the door and tightening the fastener. Ensure it is securely in place.

Step 5: Reattach the rubber plug and any other trim pieces that were removed.

Note: It is recommended to have some door panel trim clips on hand in case any break during the removal process.

Additional Tips:

If you are experiencing issues with your door lock, it is recommended to clean and lubricate the door latch before replacing any parts. This can sometimes restore function and improve the performance of the lock.

Removing the door handle

If you find a recessed slot, you can use a thin screwdriver or Allen wrench to loosen any screws inside. Alternatively, if there is no screw, straighten a paperclip or use a thin tool like an awl to insert into the slot while gently pulling the knob away from the door. This will spring the door mechanism and allow you to remove the handles.

If your door handle has a cover plate, you may need to pry it off with a flat-head screwdriver if there is a notch or cut-out on the side. If the cover plate is round, try turning it counterclockwise with a wrench or by hand to loosen and remove it. Once the cover plate is off, you should be able to access the mounting screws behind it.

Loosen the mounting screws with a screwdriver, turning them counterclockwise, and then pull the handles out of the latch assembly. If you are installing a new handle, you may also need to remove the latch mechanism by prying off the latch plate and pulling out the latch through the side of the door.

Overall, the process of removing the door handle of an E90 BMW is relatively straightforward and should only take around 10-15 minutes to complete.

Using a 4mm Allen bit to loosen the lock cylinder fastener

To loosen the lock cylinder fastener using a 4mm Allen bit, you'll need to follow a few simple steps. Here's a detailed guide to help you through the process:

First, make sure you have the right tools for the job. In this case, you'll need a 4mm Allen bit and a small hammer. It's also a good idea to have some penetrating oil or wax handy in case the threads need lubrication.

Before you begin, inspect the lock cylinder fastener to see if it's dirty or caked with grime. If so, use a small screwdriver to clean out the hex hole, ensuring that any dirt or debris is removed. This step is crucial because attempting to loosen the fastener with a dirty hex hole can lead to further complications.

Now, you're ready to start loosening the lock cylinder fastener. Insert the 4mm Allen bit into the hex hole, taking care to ensure it's fully seated. Tap the Allen bit gently with a small hammer to make sure it's securely in place. You don't want it to slip or strip the hex hole.

Once the Allen bit is securely in place, you can begin to apply force to loosen the fastener. If you have an impact wrench, this can make the job easier. Squeeze the trigger on the impact wrench and apply force in a counterclockwise direction to loosen the fastener. If you don't have an impact wrench, you can use a ratchet wrench, but you'll need to immobilize the door lock first to keep it from turning.

As you apply force, pay close attention to your progress. Keep turning the Allen bit until you feel the fastener disengage from the door lock. It's important to note that the fastener does not come out completely; you only need to loosen it enough for the lock cylinder to slide out.

In some cases, the lock cylinder might be stiff and resistant to coming out. If you encounter this issue, you can use a plastic prying tool to gently lever it out without causing any damage.

Remember to work slowly and carefully throughout the process. With the right tools and a bit of patience, you'll be able to successfully loosen the lock cylinder fastener using a 4mm Allen bit.

Repairing a broken E90 actuator

Step 1: Prepare the necessary tools and parts.

You will need a new door lock actuator, plastic trim tools, a flathead screwdriver, a Phillips screwdriver, a Torx screwdriver, and a 4mm Allen key. It is also recommended to have some door panel trim clips on hand in case the existing ones break during removal.

Step 2: Remove the interior door panel.

Start by prying off the "wood" trim using the plastic trim tools, beginning from the inside edge closest to the hinge. Then, remove the Torx screws holding the panel in place. Be careful not to lose the screws as they may fall once fully unscrewed. Gently lift the door panel, starting from the top corner near the window speaker and working your way around.

Step 3: Disconnect the wiring and Bowden cable.

Once the door panel is removed, you will see the wiring and Bowden cable connected to the door lock mechanism. Carefully disconnect the wiring by squeezing the release tabs and pulling it off. Pull the cable down to unhook it from the mount, and then disconnect it from the door latch.

Step 4: Remove the door lock rod and latch.

Working from the inside of the door, use a trim clip tool to lever off the wiring harness from the latch. There are two attachment points, so be sure to detach both. Pull the latch cable out of its holder, and then slide it out of the bottom of the door latch. Remove the door lock or door lock blank, depending on your vehicle's equipment.

Step 5: Remove the old actuator.

Unclip the wires from the actuator by reaching up from the inside of the door. There are two connections: one at the bottom and one on the side. Gently pull the white plastic end of the exterior door handle cable out of its slot in the actuator. The second attachment point should come off the actuator lever at the same time. Now, remove the actuator by unscrewing the three Torx screws holding it in place.

Step 6: Install the new actuator.

Reverse the removal process. Ensure that both attachment points of the exterior door handle cable are correctly slotted into the new actuator, and confirm that the exterior handle works before moving on.

Step 7: Reassemble the door.

Place the door lock or door lock blank back into position, and secure it with the 4mm Allen bolt. Reattach the door latch by sliding it into place and securing it with the three Torx screws. Reconnect the wiring and Bowden cable, ensuring that everything is properly seated. Finally, reattach the interior door panel, being careful not to damage the trim clips.

Tips and Troubleshooting:

• Take your time and work carefully to avoid damaging any components or trim clips.
• If you encounter difficulty removing the window glass, try lowering it so that about 4-5 inches of glass remains visible. This will provide better access to the clips.
• When removing the door panel, start from the top inside corner near the window speaker and work your way around clockwise.
• Before installing the new actuator, compare it to the old one to familiarize yourself with the placement of components.
• If you break any of the wire guides during the process, you can use elastic silicone as a replacement.
• Always test the door lock function before fully reassembling the door panel to ensure the new actuator is working correctly.

Replacing the door lock actuator

To replace the door lock actuator on an E90, you will first need to gather the necessary tools and parts. The tools you will need include a plastic prying tool, a door panel clip tool, a flathead screwdriver, and a Phillips screwdriver. For parts, you will need a replacement door lock actuator, door panel trim clips, and possibly a new door handle if yours is damaged or needs to be painted to match your vehicle.

Once you have the necessary tools and parts, the process of replacing the door lock actuator can be summarised in the following steps:

• Remove the interior door panel. This will involve prying off the vertical plastic door handle and removing the screws holding the panel in place. Be careful not to break the door panel trim clips, as they can be fragile.
• With the door panel removed, disconnect the door lock rod by pulling it straight out of the latch.
• Disconnect the door latch electrical connector by squeezing the release tabs and pulling it off.
• Pull the cable down to unhook it from the mount, then disconnect the cable from the door latch.
• Working inside the door, remove the wiring harness from the latch by levering off the clips using a trim clip tool. The harness attaches in two places.
• Pull the latch cable out of the holder at the top and then slide it out of the bottom of the door latch.
• Remove the door lock or door lock blank, depending on your vehicle's equipment. This will involve removing a cover located on the side of the door and unscrewing a 4 mm Allen bolt.
• Remove the door latch fasteners, typically three T30 Torx screws. Then, remove the door latch from the door.
• Install the new door latch by reversing the removal process. Remember to check the function of the latch before installing the door panel. You can do this by closing the latch with a flathead screwdriver while the door is open, then opening it using the cables once they are attached.
• Reattach the door panel and trim pieces, being careful not to break any clips.

The process should take around one hour to complete, but it may take longer if you are working on it for the first time. It is important to work carefully and not force any parts, as some components can be fragile and prone to breakage.

Frequently asked questions