Convertible Top Problems: Guidance Appreciated

Hello fellow Rennlisters Recently acquired a 99 996 cabriolet. Having an issue with the convertible top. Earlier on today, and once maybe a week ago, I went to close the top and it did not close all the way so I had to manually pull the top forward slightly so that it would clip into the correct place. So today I dropped the top and drove it. When I got to my destination, I had to provide some assistance again to close. When I attempted to open by turning the key in the door as well as using the rocker switch, the rear compartment opens up, however the top does not move at all. So I searched and saw that the engine compartment needs to be shut completely. I double checked and closed it again to be sure. Still, same issue. When I attempt to open, hear a few clicks and rear compartment opens, but nothing. Convertible top light is also flashing on the dash. Also, windows don't move up after they come down initially for the unsuccessful open and the interior light seems to get a power drain. Any suggestions appreciated

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Do a search on convertible Hydraulic fluid or it could need re-alignment.

I found that my headliner was binding one of the little "wings" and preventing them from moving hence the rest of the procedure was halted. If you are low on fluid it is a fairly simple fix. Do a search to find the tutorial. Here is the link but you need to be a member to access. http://www.renntech.org/forums/tutor...d-step-by-step The hardest part is getting the correct fluid. It is a synthetic hydraulic fluid. I used the VW fluid. It was about $18 for the bottle. You do not need a syringe. I used a short piece of rubber tubing and inserted it in the bottle while holding it by the top. When it was inserted enough I put my finger over the top to create suction and inserted the tube into the resoivoir and released so the fluid would flow. Like you did with a straw in your soda as a kid. One of those flexible straws may even work. Just put a rag under it as you only know it is full when it starts weeping from the hole. It is an easy fix. Hope this helps.

OK, so I am attempting the fluid level fix. Does that screw take ages to come out? I have been fiddling with it for 10 minutes and it still is just spinning, not coming out. I will keep at it, just think hopefully there is not something that will prevent me from removing the screw. Also, some posts state I can use Pentosin CHF 11s from Auto Zone. Is this OK to use? Hope to provide further update when I can get that damn screw off !

As jwex16 mentioned also check the alignment of the "wings" on each side. I had mine get stuck after I was messing around with the screw that tightens the hardtop. Using an allen wrench will get you access to the screw and you can move the wings accordingly. If they touch any part of the top during the movement process the car will stop everything in it's tracks.

I just topped of my hydraulics last week using the directions from Renntech. It was very straightforward, and my top operates great now. The next time, I will get a curved dental irrigation syringe for the job. The tubing method was a bit clumsy. Put down lots of rags to catch spills.

So I managed to get the screw off the system pump. I lost the washer however in my quest to prevent the screw from dropping into the abyss. I did some calling around but nowhere carried the Pentosin hydraulic fluid. I am a bit weary of using anything else that was not endorsed by RL folks either. Ended up making a call to the dealer. he said they have 250ml bottle for $34. Well, I had another look and the fluid was actually right at the max mark. (And the top had been replaced last year from PO). SO I played around with the rocker switch a bit more. And everything seemed to work So I put it back together. However, I am now faced with two more isues: 1. The windows that are rolling up/down very slowly. Possibly a weak battery? 2. When I try to close the top using the key in door lock, the windows do not go up after top has closed. So one thing has led to another. Well, this was the fist time I had attampted anythign on the P Car, so have some mixed feelings. Maybe I fixed something and messed up something else?

It sounds like you may need to do a system "hard reset". From what I recall, make sure you have the radio code, then disconnect the battery. You may be able to do a search this forum to find out specifics. May be something about it in the owners manual. Also, others have posted ways to reset windows. Good luck!

I tried the reset method of disconnecting the battery and then putting it back on. Radio code was no problem. Drivers side window is very slow to move up or down, compared to passenger side. Possible a regulator issue? The thing is the windows worked just fine until I started having issues with the convertible top. I may take a drive out to get my battery tested, in case that may be a factor. Doesn't hurt. And I get to go for a spin . If thats not it, what are the next steps to troubleshooting? Or head over to my Indy? Prefer to get these things worked on myself as $$ are hard to come by nowadays.

If you did not already buy and install another washer do it. Low battery could cause some of your problems. Are you opening and closing the top with the engine running or off? The top and windows are big energy consumers. I have a new healthy battery and even with the engine running you can see the power draw in the light and voltmeter.

I have been trying the top both with and without the engine running. I'll be pickuing up a washer soon and getting the battery tested also. Maybe I need to take it for a spirited drive and give the battery time to build up some energy. Worth a try, since I just need a reason to go for a spin.

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Funny you mention that. I look for every opportunity to take mine out. The other night, I took my 996 out at the request of my better half to the 7-11 to support her habit, something I haven't done in the prior 30 yrs of our marriage. With the sweet sound of the Fister D's it's poetry in motion.

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Looks like she supports your P Car habit, least you could do is return the favor

So another update in the event there may be other suggestions: - Checked the hydraulic level, it is full. The top was replaced by PO about a year ago so I expect whoever they used to get this done must have ensured this was topped up. - Located Pentosin at the MB dealer, but is it worth it if the fluid level is at the top? - There is nothing binding the wings form what I can tell. - The top works occasionally and on occasion does not. Tried it this morning, no luck, using both key in door and switch. This afternoon both methods work. What the hell is going on? Why is it so tempremental? Driving me nuts! My concern is that I dont want to get stuck somewhere if it starts pouring and I cant get the top to close. Any other ideas appreciated. I may end up taking it to the Indy at some point.

Intermittent parking brake switch? Is the parking light on the dash coming on when the top does not work?

Parking light is on at all times when the handbrake is engaged.

Hi AckyE, any update to your posts last year with your Cab issue? I have similar problems that have gotten worse over the past few days. Was it your battery, a micro-switch or something else? Any direction on the resolution to this problem is appreciated. Cheers Jason

Jason...I had the same problem and it was the e-brake sensor. Even though the dash light showed the e-brake was on, the same was not true of the conv top system. Replaced the sensor and all works fine. Good luck!

It has seemed to work OK after my last post. I have had the car in storage for the winter and am itching to get it back out to drive. I'll have to test the top once it's ready for the summer, and I'll post any updates. One more month and I'll be rolling

You may want to bone up on manual operation of your top, should it get stuck on you when you're out and it starts raining. It's pretty straight forward, and there is a cranking tool ready for you behind the back seat. Good luck!

Funny thing is that I am experiencing the same issue... "intermittent" convertible top operation. After having the hardtop installed for the last 2 winter months....now we are steady at 70-80 degrees during the day....struggling with this issue (do not want to get caught in the rain). By the way...the clam shell always opens....but the top sometimes closes...sometimes does not....

So my update: I brought the car out of storage and first time I put the top down was the day after I had taken it for a nice ride. I used the key in the door method. All worked well until it came time for the clamshell to come back into place. It did not budge. So I started the car and used the switch. Nothing. So I has my wife select the switch to cloe the top and had to manually raise the convertible top about 6 inches an and then it started moving. Then reversed the switch, everything worked fine. Next time I went to close the top everything worked. But when I tried opening the top, same thing, clamshell would not move so I followed the same procedure to open the top as described. Now what is my next step? Any ideas?

I tried again,,,it refused to close the first 5 tries...then I inadvertenly pushed one of the 2 flaps/wings and all of a sudden it started working. I wonder if those 2 flaps can be lubricated...

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I have a 99 C2 996 cab and IMHO you have two very small problems here. Where the top engages into the front slots. There are scews behind there that need to be tightened. My top would not engage fully and would go into reverse because of it. So I tightened them up (mine were loose on the left side) and all worked from then on. OK the other problem I found when I first discovered that I could lower and raise the top from standing outside the car using the door key was that I flattend (or almost) the battery showing off the action to my wife in the garage. Since I had previously been messing with wiring on another part of the car, I first thought that I had caused damage to the working part of the top. NOT SO... I put my battery on charge overnight and everything worked just fine including the windows.. Try that and I think you will find that there is nothing wrong with your car.

ANy ideas for when the allen screw head is sheared off? Yes, I know, not good. Can't lift the top now with the switch (rain tomorrow!) as the rear only lifts about 1/2" and stops. Motors are all new, top is new... worked fine for a week but no go. Went to manually close the thing for the first time, and no screw head... looks like it sheared off into the hole behind the rear deck. Ideas?

I just had the same problem. Had to replace both top cylinders due to leaking. Refilling the reservoir is a temporary fix and you could get stranded with the top down. The indy mechanic used rebuilt cylinders, still $400 apiece plus labor for a total of $1400, this did include an oil change also. I found out later any hydraulic shop can rebuild the cylinders for $75 apiece. Top works great now.

FWIW, Pentosin CHF 11 is widely used by all of the German car manufacturers in Power Steering pumps, etc.; or any application requiring a high performance hydraulic fluid. So having a bottle handy on your garage shelf is a good idea...in spite of its high cost. relinuca

I had a similiar issue. Everything is a sequence. If the rear compartment opens, then the Parking brake switch is working. My driver's side wing did not open. I greased it. Now it works fine. The previous owner had to do the same.

We don't have a Porsche dealer in Daytona BEach but BMW and VW stock the Pentosin fluid. NAPA carries it also but they were out.

Hey guys, I need some help. I have a 2001 911 996 cabriolet. The front and rear windows work when the top is up. Upon lowering the top, however, the rear windows do not work and, to make matters worse, the top will not deploy. Any ideas?

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The rear windows do not operate with the top down by design. If you simply must put them up, put your finger in the latch switch above the rear view mirror (where the latch engages) to fool the system into thinking the top is up. Then operate the rear windows. There we many possible causes for the top general malfunction. Give some more details.

Thanks for the info! I'm still having trouble putting the top back on though, it's been acting up for two weeks now. Although the "convertible" light on the dashboard comes on, nothing happens - the top will not come back up. It seems to me that the only way the convertible top will come back up is by turning off the engine, taking out the key, letting the car rest for a half hour, then trying again. Could it be that something is out of sync or misaligned and gets reset when turning the car off then back on? How could this be corrected?

There are several switches that must be engaged before the top will move. The first two I would check out are the at the e-brake handle (you did pull up the e-brake, right?) and the engine lid compartment. The emergency brake must be engaged, and the engine lid must be closed.

Resurrecting an old thread.... When I purchased my 2002 Cab last year, I already knew that cab top would only close within 4-6" of windshield, after which I had to give a manual tug. If I keep holding the button without the manual tug, the top gets a bit closer, misses the latch, a bit closer, misses the latch, a bit closer... then latches. Guys who did the PPI mentioned it was probably just a little low on fluid. Well I've added a bit more fluid (it was pretty much full already), but still have the same problem. I'm assuming that I need to go to my porsche indy to get it re-calibrated or is there anything else I could try?

Turned out one of the cables had snapped. Not sure of the exact details, it was corrected at the dealer where I had taken it for some variocam work.

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Might be a problem with faulty hydraulic cylinders. Are they leaking?

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Broken hinge, couple threads with the same problem, frisbee91 will have all the links. Right beside the latching mechanism there should be hinge that tells the top if its is done latching or not. Its either broken or the spring inside came off. I have a picture of the proper spring mouting, its little tricky took me 20 mins to go through various combinations. If you need new hinge you need a new mechanism. $500 on ebay if you lucky $900 Oem or 1200 at the dealer.

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So first off, I didn't see any leaks around the cylinders, and the reservoir seemed pretty much full. It also doesn't have a problem latching directly, its that the top doesn't get close enough before the latch tries to engage. The top moves within a few inches of closing, then the latch extends, grabs air, then retracts. if I keep holding the button the top moves a little closer, the latch extends again, this time hits just short of the latching points, and retracts. Third time, it hits properly and closes. Of course if I pull in the last few inches it works on the first try. I guess that's why I thought it's a calibration issue.

Hmm. I guess I'm not sure what causes the the top to stop at the end of the cylinder stroke. I assume it just reaches a mechanical limit, versus engaging some sort of electrical switch. Perhaps the top mechanism needs some sort of mechanical adjustment. The "calibration" involves resetting the limit switch sequence, and is thus primarily an electrical/software calibration, versus a mechanical adjustment. I would look into the top mechanism and see if anything is binding or catching that is preventing the top from fully extending. Let us know what you find out.

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I'll have a look and see if there is anything binding, I might try a bit of lube as well... maybe it's seeing some resistance which it's interpreting as the end of stroke.

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Broken off hinge causes that to do, its a weird logic. Never figured it out (like what makes it start latching 6 inches before?) but if you hold the hinge up on your top you can replicate that behaviour. https://rennlist.com/forums/996-foru...l#post11665298 Just hold the plastic up while the top is closing. As I said in my thread my half was broken and my spring was out of alligment. Glued the half fixed the spring, half broke but it is working ok with only half as long as the spring it pressing it down. I do not want to spend $500 for new unit. To the OP, do you have that hinge in place? if you do does it move freely or is it "pressed down". If its pressed down then i don't know what I am talking about. If it moves freely you need to open the mechanism and reset the spring.

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The thread you linked to has the symptoms dead on. But that hinge is in place and has pressure on it. MAybe there is something else loose in there, though no rattles etc. Before I take it all apart, I might try to blow a bit of compressed air in there and see if maybe it's a dirty contact or something.

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taking it off with a power drill is a 1 min job. But you might be right, something might be preventing from making contact, dust or something lodged in there. if you look at the last picture of the thread link on the top left there is a wire switch with 3 wires, blue red and black. shorting 2 of those could further help troubleshoot if nothing else works. I would short black and red and then black and blue. Your car think the hinge is in the up position. you need it to think its in down position till its ready to latch (aka lodge against the window) and then it needs to be up and start latching. edit: hold the hinge down while its closing, maybe the spring is weak.

You guys rock. I'll attach a pic in a bit, but the hinge you are talking about presses against a metal spring which pushes on a switch. That spring wasn't making complete contact with the switch. There was a small set screw to adjust, and a few turns of that screw fixed the problem!

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cool, the big mystery is what makes it latch 6 inches from the top. why isn't it latching sooner, ( i guess that would destroy things around it). why does it even attempt to latch with the hinge in up position? is it based on a timer? is there a micro switch somewhere else that waits for the top to be in 90 degree angle...or hydraulics in certain position. i am assuming it's the red or blue wire. the red wire sends signal to attempt latching and blue wire sends back position of the hinge. it must be a backup system. hinge is up but the top is down something is wrong lets put the top up and start latching at some point (what point?!?) . better to have top at least 90% up then nothing if its raining. this allows the top to be closed with some help even when the hinge is broken. so the engineers figure the hinge is a week point from the getco and put backup in knowing it will break for many of us. its one of the last 911 convertible top mysteries left for me to solve .

I've attached a few pictures As promised You can see how the "H" shaped hinge is pressing against a metal tab which holds a switch closed. In my case, the metal tab was probably bent a bit too much, so the switch was not being held closed. This is a close up of the switch in the fully open position (would look like this when hinge comes in contact with roof line, telling the hooking mechanism to begin Here is what it should look like in the fully closed position. This is when roof is partly retracted etc. Here is the set screw I adjusted in order to get it to work again. - Any novice could do this in 5 minutes tops. Just need the Torx screwdriver and a small hex key.

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cool pics thanks for posting, wish I had them when I was trying to re set my spring would have saved me 20mins.

I brought my 99 986 in for a ebrake switch replacement and picked it up yesterday. Got in this morning and attempted to put the top down. It got half way and stopped dead. Nothing! No movement either way. I'm not bright enough to know what to do - especially how to get it to move manually. I called my mechanic who told me that I can't do it myself and that he'd come for it in the morning. Reading through the thread I'm wondering what went wrong. It's a relatively new top which was just recently checked out by the local Porsche dealer and a few 100 Dollars later (suprisingly inexpensive) I got it back. They did tell me that the senor or actuator for the windows to go back up when the top closes needs replacing but that I can do that manually so they didn't bother replacing it. That would have been about $900. What are the steps one should take to check the top when it does these things? Thanks for your help.

Pentosin is available at a number of O'Reilly's Auto Parts chain stores. Go to their website to check availability near you. I got mine for just under $20. Note you might have to ask the clerk as my store hid it in the stock room. You can also have them send it.

OK, resurrecting a dead thread. I hated to start a new one just for this. I recently picked up a 99 C4 and sometime the top works fine and sometimes not. It appears that what is hanging it up is the wings/flaps (is that correct terminology?) some times do not come completely up, or down. When trying to move them manually they seem to be be locked in place. Today it got stuck with the top all the way down but the clam shell would not close all the way. The right wing flap was still up. Top would not go up or down. I reached in trying to not get my hand cut off and flipped the micro switch on the flap and badaboom it went right up with no issues. So now stupid question time. I see the flaps ride on a couple of nylon clips on metal tracks. Is there any way to lube them? I also see but have not messed with it that my Durametric has a convertible top option. Can this be used to diagnose or fix anything? Any advice on what to look for in there? Am I just stuck in taking it to someone that knows what the heck is going on? Any other advice or things to try would be appreciated. I read most of the thread I could find and no I have not pulled the top and checked the fluid yet. Bad Me I know but the top was serviced about 5K ago, not that that means anything. Marc

I had the same issue a while ago. Those wings/flaps are spring loaded and swivel on small plastic gears. If the springs have lost there tension they do not lift the wings/flaps enough. You can put your top in service mode where the wings/flaps are folded vertically before the top fully closes so they are exposed. I pulled the springs on each side apart so they are set with more tension and also took a clean paint brush with some spray cleaner and brushed them good. A lot of dirt and grease accumulates on them and causes them to stick and not spring up as they should so the micro switch doesn't engage and the top stops working. Then a good coat of white grease on the gears. If you notice that the flaps are sort of sagging when the top is fully open, that means the springs are worn and are not putting enough force for them to pop the wings/flaps up. The springs may be able to be replaced, on mine I just, as I said, pulled them apart to increase the tension. Kind of like pulling a coil spring apart to increase the tension. Before I fixed the springs I had my wife or a second person pull them up as I operated the top so as to engage the micro switch. One springs were corrected and gears cleaned and lubricated, all has been well.

Thank you very much for the information. The springs seem to be fine and the flaps move, folding wise, very nicely. But as you say I need to grab them and try and pull them up or push them down vertically when trying to operate the top. I think I need longer arms. I will try and get down in there to see if I can see any gears and try some white lube on things that I can reach. Thanks again.

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Curious... LoMax, do you store your Cab in a garage daily or leave it outside? I keep my in the garage and it usually operates fine, but I've been noticing that it sometimes struggles to open and enclose the top. I'm wonder if this is a sign that it will need to be serviced soon. Anyway, just curious. Thanks!

It has been stored in the garage since I got it but as motorcycle riding season is coming it will be spending more time in the driveway.

Well since I resurrected this dead thread here goes another one. I am going to open things up and lube everything and check the functions. I would like to check the hydraulic fluid also. I went to two Porsche dealers today and neither of them had the hydraulic fluid or a new washer for the filler plug. They could not even fine the washer, REALLY come on Porsche. So this is an open call to any of the vendors here to PM me on some hydraulic fluid and a new washed for the fill plug. ARGGGGGGGG! Off to the garage now to see what kind of problems I can cause. Update, Looks like it is service shop time. BTW: the pump was full of fluid and it looked good. Everything on the top works just fine but the lateral flaps are not activating, thus it is hanging the top up for opening and closing. If I manually open or close the flaps then the tops works flawlessly. As they did work once upon a time I am hoping that a full re-sync will fix it, if not then it may be flap motor time. Durametric will clear the codes showing "time out" but will not sync the top functions. Whee get to spend more time and money. It looks like dealer time as there are no Indy's open on Saturday and that is the only day I have off. Drat. Marc