It is not uncommon for a modern car door to refuse to close. In this article, we will discuss how this can happen and ways to resolve the issue.
In addition to latch problems, we’ll cover a few other reasons why we might hesitate to lock a car door.
See also: 13 different styles of car doors
How does a car door locking mechanism work?
Door latch designs have been developed for decades. Modern latch mechanisms function to keep the door firmly attached to the adjacent jamb while driving and in the event of an accident, while also allowing the door to open in the event of a collision.
This is accomplished by using a jaw-type lock or a rotating prong lock.
When the car door closes, either of these types of latches will firmly grip a headpin or U-shaped impact bar on the door jamb. Whether your car has a clamp or a rotating tooth latch, we will only use the term clamp for our discussion here.
When you open the car door by pulling the lever or door handle, the locking mechanism releases the jaw and the door opens. The jaw is then held in the unlocked position by the locking mechanism. When the door closes, the jaw hits the striker and pushes it back into the locked position.
Related: 4 Reasons Your Car Window Won’t Roll Up
Reasons why a car door does not close completely
So your car door closes but does not lock and can be opened. Or the door when it is closed but bounces when opened.
#1 – Jaw Lock Closed Engagement
Examine the door latch that does not close. Now examine another door that opens and closes correctly. In this door, you will see what a completely open jaw looks like.
If the latch on the door in question is not in the fully open position, the door will not close.
How to fix
- While looking outside, use one hand to pull on the door handle or handle as if you were going to open the door. This should release the jaw and it should return to the fully open position. Release the door handle. The jaw should remain open.
- Using a screwdriver, try to push the jaw into the closed position. It should move easily to the closed position and snap into place with a ‘click’. Now pull the lever or door handle again. The jaw should click back into the open position.
- Test the operation of the door. If it locks in the closed position and reopens correctly after three or four attempts, you have solved your problem.
- If these steps don’t solve the problem, your car’s door locking mechanism may be faulty. Corrective action will be required by a qualified technician.
See also: How to fix a seat belt that won’t retract
#2 – Jaw does not stay in locked position
Examine the offending door latch. If the jaw is in any position other than fully open, there may be a problem with the locking mechanism.
How to fix
- Using a screwdriver, move the jaw to the fully open position. Then move it to the closed position. It should ‘click’ when closed. Try moving it with the screwdriver. It must be held firmly in this position.
- While looking outside, pull on the door handle or handle as if you were going to open the door. This should free your jaw and it should open. If not, the locking mechanism may have failed. It is also possible that the jaw-locking mechanism is dry and seized due to a lack of lubrication. Follow steps (3) and (4) to loosen and lubricate the jaw.
- You may need help with this step. Ask your helper to hold the door opener or handle as if they were going to open the door. Using a penetrating lubricant such as WD-40, lightly spray the caliper pivot points. Do not overspray. Move the jaw back and forth with the screwdriver until it moves freely. Release the door opener. Push the jaw to the closed position. Wipe up any sprayed lubricant.
- With the jaw in the closed position, pull the door release lever. The jaw should click into the open position. If it does not move or only partially moves to the open position, the locking mechanism may be defective. Corrective action will be required by a qualified technician.
Read also: 4 reasons to get in your car
#3 – Misaligned locking jaws and firing pin
A small previous collision can cause a stuck door which, in turn, causes the latch jaw to not line up with the strike plate on the block. Alternatively, the hinge fasteners may be loose and allow the door to move out of proper alignment.
How to fix
Corrective action will require realignment of the door. This can be a difficult process for a DIY mechanic. In most cases, it will be necessary to take the car to a quality body shop for corrective action.
#4 – Freeze Lock Mechanism
In a modern car, a frozen door latch rarely occurs. But it can happen.
Such an event can occur in this way:
Your car has been parked outside during a storm for some time. Precipitation combined with low temperatures has frozen the windshield and windows. You open the door to catch your scraper and the door won’t close. The locking mechanism is frozen so that the jaw will not open or lock completely when the door is closed.
How to fix
There are three possible solutions here:
- First, don’t slam the door. This could damage the latch jaw. Instead, with the door slightly open, pull the opener lever or handle and release it again a few times. Often the impact of this action will release a frozen locking mechanism. If that doesn’t work then…
- Get in and start the car. Close the door as much as possible. Warm up the engine and turn the front windshield defroster to “high.” Adjust the heating temperature to the highest setting. This will warm the interior of the car, including the door assembly. It may take 15 to 20 minutes to defrost the door-locking mechanism. If that doesn’t solve the problem, there is another option…
- You will need hot water (at home, for example). Start the engine and defrost as described in step (2) above. While the car is warming up, fill a kettle with warm (not boiling) water from the tap. When the car interior and windows are completely warm, keep the door tightly closed. Now, slowly pour the hot water over the back corner of the door above the outside latch handle.
- After each of the above procedures, close the door to see if it has resolved the problem. If the door is still not locked, you will need to contact a service technician to take corrective action.
See also: Best car covers for snow, ice, and hail
#5 – Corroded jaw area
With older vehicles (especially those that are stored outside for long periods of time), a lot of corrosion in the jaw area can prevent the car door from closing and latching.
How to fix
A stuck latch due to heavy corrosion can be corrected by following steps (3) and (4) in the previous section discussing jaw lubrication.
#6 – Locking Mechanism Failure
The lock’s operating mechanism may fail if none of the above steps correct the problem.
How to fix
If so, the locking mechanism will need to be repaired or replaced by a qualified vehicle technician.
See also: 5 Signs of Structural Damage in a Car