If a door in your BMW 4 Series squeaks when opening or closing, it is not only annoying, but can also reduce the longevity of the door. We discuss in this article how you can eliminate and prevent such squeaking noises in your vehicle.
What causes a squeaky door in 4 Series?
The squeaking usually comes from the door check or the hinges. 4 Series doors have a relatively thick layer of grease from the factory, but the lubricant degrades due to the frequent opening and closing of the door over many years. If the lubricant is no longer available or only insufficiently available, metal rubs against metal – and this leads to a squeaking noise.
How to fix a squeaky door in 4 Series
There is a quick remedy for a squeaky door in 4 Series. Since the lubricating layer is missing when it squeaks, it only has to be relubricate with a new agent. Slowly open and close the squeaky door. If you listen carefully, you can localize the noise. This way you know which hinge needs to have its smear layer restored. This is where you apply the new lubricant – but it is recommended to lubricate all door checks/stops and hinges on all doors of your vehicle.
Use white lithium grease spray
In majority of the workshops, white lithium grease is the product of choice for lubricating the doors. White lithium grease is a thick spray grease that provides long-lasting lubrication without dripping or running. The product is particularly suitable for reducing the friction of metal parts and thereby keeping the connections smooth.
How to apply white lithium grease
- Fully open the door that is making noise in your 4 Series.
- Clean the door hinges first if they’re dirty.
- Spray some white lithium grease into the hinges and the door check.
- Open and close the door a few times so that the lubricant can get inside as much as possible.
- The squeaking noise should be gone.
- Clean any excess lubricant with a dry cloth.
Do not use penetrating oil
Do not spray penetrating oil like a regular WD-40 on door hinges, it will remove the existing grease and then evaporate quickly, causing squeaking noises again after some time. At minimum use silicone lubricant, but white lithium grease is recommended.
Replace the door check assembly
If lubricating the door doesn’t eliminate the squeaking noise in your BMW 4 Series, you may have to replace the door check assembly. The internal components of the door check may have corroded or worn out and making a squeaky noise.
Warning: If you choose to replace the door check yourself, be careful not to fully open the door after the door check has been removed. If the door swings open fully due to strong wind or human error, it can cause damage to the body and paint of your vehicle.
Using engine oil as a lubricant
If you don’t have white lithium grease and don’t want to purchase one (its only 10 bucks), you can use engine oil to lubricate the doors of your 4 Series. You may have some lying around your house from your last oil change, you don’t need much.
Prevent squeaky door
Small care measures are enough to prevent the doors from squeaking in 4 Series. Regularly remove dust from the hinges with a vacuum cleaner and check a few times a year whether there is still a sufficient layer of grease. When the lubricant is almost gone, you should apply more before the door can start to squeak. It is generally recommended to lubricate the doors once every year or a couple of years.
Lubricate the door latch
It is recommended to lubricate the latch on each door of your 4 Series at-least once every few years for smooth operation and longevity. You don’t need to get a separate lubricant for this purpose, you can use the same white lithium grease to lubricate both the door hinges and latches.
Lubricate the hood and boot latches
While you’re at it, lubricate the hood and boot latches as well. It will ensure smooth operation and improve the working life of the component.
If a door in your BMW 4 Series is making squeaky noises when opening or closing, you should always start by lubricating the hinges and the door check/stop. If that does not work, then consider replacing the door check (if the noise seems to be coming from it).