mpcevat

I have a 996 C4 Cabrio Tiptronic MY 2000 ROW (European spec), with just over 130,000 Kms done. Last week the Lock-up Clutch failed. I took the car to an OPC, but it seems they don't have transmission specialists employed. First option the workshop came up with was to change the torque converter unit and if that would not work replace the gearbox. Obviously all at my expenses. I'll safe you my opinion :censored: . On this forum I found a few alternative solutions :renntech: that I mailed them to look at first: ATF to low or old, i.e. compressible because there's too much water in it; MAF sensor faulty; bad wiring between DME and Tiptronic. They have checked these, but all seems well. Now they want to take the car to a transmission specialist while at the mean time they mailed the symptoms to the service network at the factory (reason I don't do that myself is that the OPCs here have fixed service prices; I don't pay for all the extra hours, just for the solution and parts). Still I don’t believe the torque converter unit or gear box are broken. Can anybody help me with following reasoning: the engine runs as beautiful as ever :) gear changes go just as smooth as always, both up and down through all speeds what should happen at speeds over some 60 Kmh is that when the input and output speed of the torque converter is about equal, the lock-up clutch is engaged that does not happen: the revs change immediately when I press or release the accelerator; normally when the lock-up is engaged, the revs are more or less fixed with the driving speed only until brake or kick-down is used; the remaining slip in the torque converter means that the engine runs at over 2500 RPM for just 100 Kmh, which is absurd if the torque converter unit would be broken, this would imply some part came off internally; the unit then would run out of balance, which immediately is apparent; it does not resonate at all at any speed between 1000 and 5000 Rpm My conclusion is that the next things they should look at is the solenoid valve that directs the ATF through the torque converter. It should reduce ATF pressure behind the clutch plate, through which it closes (re page 14 in http://www.autoshop101.com/forms/AT02.pdf ; I know that's from another brand, but it is the same ZF technology). Any other (better) ideas where to look and documentation to look at? Your help would be appreciated! Cheers, Marco

Hi, I have a 2001 996 C4 cabrio tiptronic with a CDR-23 installed. I would like to replace it with a second hand PCM1 16 bits version I bought through ebay. I must have spent about an hour searching for a topic there used to be on Renntech about this mod. It contained extensive guidelines on installing the PCM1, a list of required parts and lots of pictures. There is one on PCM2 on http://www.renntech.org/forums/index.php?showtopic=7068, but I'm looking for the older version. Could somebody please direct me to this topic again? Or has it gone lost somehow...? Thanks in advance, Marco from Zeist, the Netherlands

On my 2001 996 cabrio tiptronic I replaced the plastic stuff Porsche installs off-factory with a set of dual cones wide band Pioneers that fits in the dash, a pair of MB quarts 1.5" tweeters that fit next to it, same Poineers in the rear and a pair of original (but second-hand) 6" Porsche woofers on a 300W JVC mono amp on the subwoofer output of the CDR22. To get the speakers in the dashboard, I reused the frame that the Porsche speakers came with; just some drilling to get the holes in the right place and glue did the rest. Because the original door panels for subwoofers are quite expensive, I modified the standard panels: removed the storage compartment and made a speaker cover to fit behind the hole. To pull it flat against the door I could not use the standard plastic clips, since there is to much tension on it (it stood about a quarter of an inch open). I needed to use a long screw that fits in the catch where the clips normally go, so no drilling required. All speakers in their original places, completely invisible and the sound is A1. My Porsche dealer found me two very small Porsche badges to cover the screw heads. Total operation took about half a day to complete.

Dear Loren, Thank you for that Technical Bulletin. It proved very helpful in the sense that it made clear there was something (very) wrong. I did seem to miss the plugs, wires and CD Changer holder that was specified in it. Also the doors were pre-wired, but now I took everything apart, it seems that at the other end of the connector (body side) there are no wires either. One phone call later to the nearest Porsche dealer I found that my Porsche did not have the option code for the basic Radio Preparation Kit. It looks as if the previous owner had no audio system installed at all (deaf?). So after about a full day of hard labour I have a 100w amp installed below the passenger seat, wired the connectors between body and door, and hooked it all up to the TraficPro 4600. It all works fantastic. Last thing left is to install the grills I made to cover the M490 subwoofers in a "non-Hifi" door. If that works, I have everything installed without drilling a single hole and without it showing (except, of course, that the door pockets will be covered with a mesh and cloth). Thanks for your help. :thumbup: Marc Cevat

Hi, Nflight, adjusting the door is not an easy job. The Porsche workshop manual spends some 15 pages on the subjects of window and door adjustments alone (996 manual, Group 5, body). Simple hints wouldn't do. It might therefor be a good idea to order the manual on CD from www.workshopmanual.co.uk at some 10 UK pound. Success, Marc Cevat

Loren, Thanks for you reply. I checked today and think that I must have the only 996 which must have the amplifiers mounted somewhere else. I attached a photo that shows what you find in the trunk of my car. Any further ideas where I could look? Thanks, Marc Cevat

I just installed some used M490 sub woofers in the doors of my 996 (non-hifi covers; still working on the grills). The speakers just simply connect to the existing wiring. I have problem locating the other end of these cables! I assume that would be the location where the M490 amplifier goes, but I don't know where that is and the workshop manuals do not give me any clue. Can anybody please help me? Marc Cevat Netherlands mpcevat@xlmts.com