Driver's window fault

[Ripmax]

*sigh* another fault has developed, this time with the driver's window. The motor is struggling to lower the window by the usual amount when I open the door and it's barely clearing the rubber seal. It's the same when I close it; it's really struggling to wind itself up into the seal. To be sure the window's low enough before closing the door I have to open it manually a bit first . A few times it has got itself stuck in a loop: it tries to close itself, fails, winds itself down a bit, tries again, fails... This has conspired with the failure of my central locking to prevent me from locking the car at all at times (locking the car with the key initiates the window mechanism, which then gets itself stuck in the above loop). I've been having to close the window from inside with the button, climb out of the passenger door and leave it unlocked. This started on Xmas eve - probably the worst time of year to break as garages are shut for days. Any ideas? I've lubricated the mechanism and runners but this has made no difference. What usually causes this?

I'm taking the car to an independent Porsche garage tomorrow to see what the diagnostic machine makes of the central locking fault, which is irritatingly intermittent. It usually breaks itself after 45 min drive so fingers crossed it does that in the morning. So far it's randomly fixed itself after hours or days parked on the drive. The central locking started playing up before the window so I don't think the two issues are related.

Since I bought the car in October ('99 996 C4 with 81k and full Porsche service history) the oil pressure sensor has failed and now the central locking and drivers door window mechanism. Although used to owning old cars over the years this is my first Porsche and I'm beginning to be disappointed with the build quality. Thankfully it's not my only car.

 

[Gordon Attar]

The sensor that effects the window lowering and raising the window slightly when opening the door is the door latch sensor, part recently cost me £81+v when recently replaced by Northways, mine was not always lowering when opening the door. I believe it also can have an effect on the central door locking or vis-a-versa.

Did the car come from a trader with a warranty!? If not then , you should expect some wear and tear faults as the car is 13 years old.

 

[Richard_Hamilton]

Does the window work smoothly on the button? If you get the window half way open, can you pull it up and down a bit if you grab it by hand? If the motor is struggling, and there is some play in the mechanism, it may well be the window regulator (cables) which are failing. If so, it needs changing, but I don't think it is related to your locking problem. The car would lock, no matter what position the windows are in. As Gordon says, that is most likely one of the microswitches inside the door lock assembly.

 

[Ripmax]

Tks for your responses. The window does work smoothly all the way up. The window is trying to lower itself when the door handle is pulled but it only achieves about half the normal distance, which is barely enough to clear the door seal. I've just been looking at the workshop manual and it refers to an adjustment valve - "Adjustment valve for window lowering function approx. 13mm". Do you know where this valve is?

 

[Ripmax]

No, you can't move the window by hand - it's solid...

 

[Richard_Hamilton]

I'm not aware of a valve. Are you sure that doesn't read 'value'?

 

[Ripmax]

Defo says valve...

 

[Diesel130]

ORIGINAL: Ripmax

Defo says valve...

If Richard isn't aware of a valve, you can be sure there isn't one ... suspect Porsche made a typo!

 

[Ripmax]

No doubt. It misses out a step to take the door trim panel off too.

 

[Richard_Hamilton]

That's a very old manual, but it is a typo they have carried forward to much later versions.

Is it the plastic screw in the door pocket they missed out? Seems to catch most people out.

 

[Ripmax]

It's not at all obvious that screw's there in the workshop manual I have. They refer to a compression screw, which may or may not be it. If you peer closely at the picture the plastic screw is shown but I missed it the first time I tried to remove the panel.

I took the car to the garage but the central locking was working, typically. They connected it to the ECU and looked in the log but it was full of alarms linked to the central locking and window failing - too many to know what was the root cause. The feeling is that it's the driver's door lock though. While it was there they lowered the height of the driver's window and that seems to have fixed that issue.