Need Help.
This weekend I tried to unlock the car using the key in the drivers door. When I unlocked the door the rear locks actuated but the lock quickly popped up but immediately went back down. Sounded and looked more like it cycled. Just a quick up and down. I tried again and they stated cycling several times on their own, stopped and then nothing. I was then unable to lock the drivers door using the key after that. The passenger door lock always had an issue, but this never happened. any Ideas? Thanks in advance for any help or suggestions.
Oh, I am working on a 1993 XJ40

 

The car has a central locking system, so under normal conditions locking and unlocking the driver's door locks and unlocks the rear doors too.
From your description of the issue, it seems the driver's door actuator/switch/lock is where the problem lies.

Larry

 

When the actuaries encounter too much resistance from the latches, they “keep trying” a number of times to try to lock.
The best fix is remove all the door cards, lubricate the internal latch mechanisms with spray white grease/ Lithium Grease. Work the mechanisms manually as you spray to help move the lubricant around. You should find the latches operate far easier, and even the out door handles should open with less resistance/ effort.
It’s not a “quick fix” so it does take time and effort, but it will almost certainly fix the issue, and likely save your outer handles from breaking too.

 

I did need to disassemble the door trim for clean/lube every few years when mine did that same thing.
I lubed dozens of customer cars for that reason.

Sometimes you can get a spray can of penetrating oil and lower the windows so the spray can be directed at the latch assy.
The plastic curtain might be in the way?

Some oil will likely drain out the weep holes in the bottom of the door.

 

That’s a good short cut idea. If you are short on time.
Though the door cards don’t actually take that long to remove/ put back. If you use a powered drill/ power screwdriver, it saves time on the screws etc. It’s well worth the time investment to do it thoroughly. Chances are it will only need doing once. Every 28 years! So the lube will outlive the rest of the car.

if you own an early model 3.6/2.9, this job is even more critical. As those outer door handles are not strong, abs very prone to snapping.
ever 3.6 xj40 I have ever seen has had broken door handles at some point in its life. Regardless of mileage.
the later cars have stronger handles, but I have still seen a good number break. Specifically because if stiff latches.

 

Sounds like mine...big resistance to the lock knob travel up and down...the actuator is getting power and trying to move but wont shift the linkage. The linkage seems loose as well whichwould put things out of wack. Sprayed oil in there no change will have to have a go with lithium grease!!!

 

when you say you sprayed oil in.
did you remove the door card to gain full access?
if there is play in the the outer handle, you should be able to adjust it out. It’s really not a huge job to remove a door card. Well worth the bit of time and effort.

early models- this job is absolutely critical if you don’t want to spend money on replacing outer door handles. They will break if forced.

 

Yes door card was removed. Will do it again have a proper look see how I go. Mick

 

Which year is your car?

 

91 sovereign vin 658822

 

Ok good. The handles are stronger on 90-94 models. It’s still well worth doing a proper job.

 

...same problem on a '93 XJR. I had to remove the panel and lubricate the actuators. Both.

 

Indeed. I think they all need it by now.

 

I like White Lithium Grease in a spray can for lubricating the door lock linkage, latches, etc. It leaves a thin grease layer that is longer-lasting than penetrating oil or machine oil.

Also, another issue to check for is that the upper edge of the plastic interior door trim panel (door card) tends to warp in the sun, which can cause the chromed plastic ferrule around the door lock plunger or "button" to bind, sometimes adding considerable resistance to movement of the lock button. You can remove the ferrule ("lock button surround") and test to see if your actuators work more freely without it. If so, one solution is to lubricate the inside of the ferrule with dielectric grease. A more effective and permanent solution is to carefully heat the door panel with a heat gun and reform it so the top surface is more horizontal.

Cheers,

Don