Erling G-P

Just curious; does anyone have the background for Porsche's decision to do this ?

My own motor runs, but only opens the hatch in about 20% of my attempts; for the remaining ones, I have to resort to using the key.

Recall reading elsewhere here, that the rear hatch opening motor system is one of the most complex items in the 928s.

Thus puzzled about the reason for selecting such a way to do it - why not just a simple cable pull (which worked just fine in my first-car Toyota)

Cheers,
Erling

mj1pate

Porsche embarked on a benevolence to take care of the growing contingent of Bavarian clock makers. The door lock and rear hatch mechanisms were naturals to put them to work. The result is the entertaining cacophony of whirring, buzzing noises that you hear when you activate these electromechanical marvels. If you lean closely and listen very carefully, you can hear a little fragment of the Pinocchio "Gepeto" tune, played by tiny music box harp...

Mike

Erling G-P

LOL Mike, thanks for that explanation - things are now much clearer for me..

Cheers,
Erling

JEC_31

Erling, excellent point.

This may very well be a case of over-design ("Let's make the world's most advanced hatch opening mechanism!") followed by under-funding ("To make up for the huge cost overruns from the design department we'll use cheap materials").

I do not relish the idea of converting a 928 to cable-pull - that's a lot of planning and tearing into the car, then a lot of bracket fabrication, maybe some welding and riveting.

Alan

Really I don't know - a simple cam actuator with a solenoid drive should have been enough - no parking mechanism required...

I suppose we can be grateful it isn't vacuum actuated though...!

Sometimes it appears the engineers weren't well enough supervised and started "overdoing it"...?

Alan

Richard S

My 1967 Buick Riviera has a vacuum actuated trunk release. It has worked perfectly, never any problems. My grandfather (he purchased the car when new) was always expecting it to quit working, but it outlasted him. Open the glovebox, push the little red button, hear the pssssstaaah of the vac system, trunk opens every time.

Rich

Erling G-P

Thanks for the input guys

"Ein kabel-pull ?? Idiot!! Dummkopf!! Dis is supposed to be unseren state-of-the-art auto!! Wir kann nicht use such ein simple system! Machen something mehr kompliziert bitte !!"

Cheers,
Erling

Nine2Eight

I think it all stems from authorized German Beer breaks at the Porsche Werks.

BrianG

When my trunk opening clock-works retired, I replaced the unit with a simple solenoid operating the stock latch-release flag mechanism, thinking that this would finally resolve my intermittent functionality of the remote trunk release. No dice! Half of the intermittancy problem is actually the issue of the alignment of the two mating parts of the locking mechanism. If they are mis-aligned, the stock flag mechanism cannot move the nylon latch far enough to disengage it from its mating latch-piece.

After messing around with the latch alignment (unsuccessfully), I decided to modify the latch-release flag part by making the flag tab project further. Thank heaven for TIG!! A 50% increase did the job. Releases are now 100% reliable, and I suspect that this modification would have a similar effect on release reliability, even if still clock-works driven.

LT Texan

Thanks Alan. My vacuum actuated locks recently stopped working perfectly. Now the system loses vacuum after about 5 minutes. Can't wait to hunt that one down.

daveo90s4

On my 1990 S4 the pull **** will only activate the motor to release the hatch if one of the doors is open. As a consequence, pulling the **** accidentally (??) while driving will not release the hatch (assuming you're not driving with the doors open, of course!).

So could there be some safety reason for the complicated set up? A simple cable could release the hatch while in motion?

Nah, can't be - more likely simply over-engineering!!

Erling, by placing a 1 Euro coin under each edge of the body-mounted latch plate (near each of the hex head bolts) cured my intermittent hatch release problem. This fix has worked for others too.

Regards

jpitman2

Apart from the hatch and receiver getting misaligned, the bush from the link to the operating arm can break up and produce enough slop to prevent correct operation. I fixed one by making a brass bush (7mm od, 5mm id), and retained it with a 2-56 screw into the arm. Shouldnt be too hard to find a piece of tubing to do the job....
jp 83 Euro S AT 51k

Alan

DaveO - yes they deliberately went to great lengths for that safety feature....

It does make you wonder how much downforce the wing makes - that they are still worried it will fly open...

Who wants to test this...?

Alan

ew928

Alan,
I once drove about 200 miles (upstate NY to NYC) without having the hatch latched. I'd closed but forgotten to latch it with a nice forceful push.
Mostly highway driving. 60-80mph stuff. Only when I got back to bumpy NYC did I hear a strange rattle from the hatch bouncing up on the bad pavement.
And that's with non-collapsed hatch shocks.

You guys shouldn't complain. Hans und Franz could have duplicated the hatch lockdown unit for the front hood. But we all know that 928's are so reliable that owners rarely open the hood.

Erling G-P

Thanks Dave, must see if I can use this trick too. Wonder if it'll work with other currencies, or if it's only Euros that will do...

Cheers,
Erling