Errr noise

This has been a bit confusing, including for the dealer. The car is '03 996 C4 Tip, when put in gear or into P or when the engine is turned off, it would make an 'errrr' noise. Also only happens when the engine is warm. It's been like this for some time now. The dealer couldn't find out whats wrong, and they would've been hunting for fault codes etc. The only guess was valve body or servos filling up, and they suggested to replace trans oil, although the oil was only three years old. Another 996 owner ('98) which would have different transmission to mine had the same problem, here's the posting @ another forum I forgot to record the noise just now, would do that when taking the car out again (next weekend).

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Ok, the fluid is reasonably fresh. Is it the right fluid? Is the fluid level ok? Are there any leak signs at the Tip? Shifting a Tip into P after the engine is turned off is not the normal sequence of steps. I do not have a Tip equipped car but if I did I'm a firm believer in following the recommended sequence of steps and I would not do what you do. If you tell me the noise only occurs once when shifting the Tip from D to P after you have turned off the engine I would offer the WAG the noise is from some portion of the Tip hydraulic system bleeding down. In D the clutch packs are pressurized some -- which is why the car wants to move forward when you take your foot off the brake. When shifted to P then the fluid that is holding the clutch pack in partial engagement is released. What you hear could be the noise this fluid makes. If you shifted to P with the engine still running the engine noise would drown this out. If you tell me the noise occurs over and over again as you move the shifter from D to P after having moved it back to D again I would offer the WAG it is some electrical system that is being activated. If the Tip behaves otherwise, if the fluid level is ok, I'd advise you stop shifting from D to P after you turn off the engine, but instead do this shift before you turn off the engine.

Thanks Macster. To answer your questions, the dealer did the fluid replacement, and there is no leak. Sorry I wasn't clear on the original post, I would shift from P to D or to R, or from D to R back to P, all with the engine running, and the noise would happen. I also meant to say that with the engine running, I would shift to P and when I turn the engine off, that would trigger the noise too. If listening hard, the noise would be audible with the engine is running.

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Ok, then the noise is something that essentially came out of the blue, and can't be attributed to operator error, and doesn't appear to have anything to do with the fluid level or condition. However, I note the dealer did suggest a fluid service. My limited 1st and 2nd hand knowledge of Tips (and automatics in general) is when they start to make noises, start to act up, that is generally bad news. My automotive tech friends/advisors have impressed upon me the best time to prevent (if they can be prevented) automatic transmission problems is with properly scheduled fluid/filter changes. No need to get all crazy with Tip fluid servicing, just if the fluid/filter service is scheduled at say 90K miles at least have it done at 90K miles. Better yet would be to have it done sooner. One can get any service interval mileage number if he asks enough people but the consensus is if one wants to be real proactive to cut the 90K number in half. A good number of people wold offer that reducing that 90K miles by 1/3rd, to 60K miles, is sufficient. (FWIW, I have changed the transmission fluid (5-speed) in my Boxster at anywhere from 90K miles to around 60K miles and so far the transmission seems to be holding up very well.) However I know you can't go back in time and do this. And maybe it was done, by you or the previous owner. Furthermore, even with more frequent fluid changes some transmissions are not just going to last as long as others. So, where does this leave you? You can listen to the dealer and its recommendation and have a Tip fluid/filter service done. A word on this: My sources tell me that often at least in the case of a Tip, that a fluid change when there are symptoms, seems to hasten the Tip's demise. Now I wonder about this. No one can know what the outcome would have been had the fluid not been changed. IOWs, the Tip's demise would have occurred anyway and within the same time frame, too. If I were in your shoes I would have a positive outlook and assume the fluid change would help, or at worst have no negative effect. But you have to be mentally prepared for the possibly worst of the worst and that is the thing just up and croaks in seeming a short period of time. Whether the fluid change played a role -- I doubt it but can't say for sure -- or not no one can say. Thankfully, I have not actually had to have a transmission worked on, but a few times with my Boxster I have faced the possibility of having to have a manual transmission worked on due to its behavior. But before committing to this I have been willing to throw a fluid change at the behavior, or even more recently a brake/clutch fluid flush and bleed, and lucky me the fluid change, or the clutch fluid flush/bleed, made the behavior go away. So, getting the Tip a fluid change is one thing to consider. Another is you can get a second opinion. (My opinions do not really count as a 2nd opinion as I am not a professional mechanic. Our conversation is more a friendly exchange of ideas/thoughts.) My info is Porsche techs do not rebuild Tips. They perform fluid services on them, swap them out (most often under warranty), but they do not open the cases and work on them internally. If there is any rebuilding to be done, it is done by an indy transmission shop, one that specializes in Tip transmissions. Thankfully what I hear is these shops are common and a number of them do a very good job. (In the event a rebuild is called for the tech may be asked to drop the Tip so the rebuild shop can pick up it and then afterwards install the Tip back in the car.) The Tip is made by Z-F and Porsche is not the only car maker to use a Z-F transmission. These indy transmission shops see a lot of Tips/Z-F transmissions and if the thing is salvageable a good experienced shop should be able to bring it back up to snuff. So, what you can consider doing is researching to find the best Tip/Z-F shop in town or in your area. Pay it a visit and get its opinion as to what is going on. What you are told, or not told, will determine your next step.

Before you toss fluid at the noise or even consult with a tranny shop, are you sure the noise is coming from the transmission? Could the noise be coming from say the dash? Or from some other area other than the tranny? Have you or a tech positively determined the noise comes from inside the transmission?

Thanks again for your comprehensive replies Macster. 1. I will need to get second opinion, unfortunately that the other crowd would be an indy who isn't open on Saturdays and since I tend not to drive the car on weekdays (difficult to park it safely), I haven't had the chance to catch-up with the indy. I actually had the car in with them a few months ago to replace the voltage regulator, but since the noise only happened when the car is warm I forgot to get them to check the noise :-( 2. The dealer had to replace the transmission oil three years ago just after I bought it due to a gasket leak. They had to manufacture a replacement gasket themselves. There is no leak under the car at the moment as I had been spending a lot of time under it to fix ( a coolant leak 3. The noise only happened when the selector is moved to/from D, P or R, or when the engine is turned off. It doesn't come from the dash, and remember the dealer told me that they haven't got a clue but the tech thought that it might be "valve body or servos filling up". It sounds like coming from the rear of the car. 4. I put a link in the original post to another forum post where the OP had the same noise. His was a '98 which had a different transmission to mine.

Reviving this thread, especially no one still knows the reason, and I at last managed to remember to get the sound. To recap, on Tiptronic regardless whether it's the new or old gearbox. Only happened when the gear lever was moved from N or P to R, or D. Or the car's turned off and on P. Only happened when the car was really warm, and after a spirited drive. Never occurred after it's first started on the day, or when it's cooled down. The video captured the noise on the following seconds : 3, 8, 14, 19, 23 and when it's turned off at 31. I put my phone on the ground just below the B-pillar, on the right side of the car. http://youtu.be/NPEScjeTEPo

That is a very distinctive noise. My advice would to be to get the car on a lift and let a tech listen. An indy tech, as I take the dealer techs have heard the noise and can only offer "valve body or servos filling up". In fact I'd almost give the indy tech a miss and visit a trusted automatic repair shop in your area that specializes in Tip's. These are used in Audi's, VW's and possibly other cars. Anyhow, as for the dealer techs, they have taken this as far as they can. At this point if the car was under warranty they'd probably be on the phone to the factory sourcing a replacement Tip. My point is by listening the tech can id the source of the noise and from this have a better idea. Even if you know where it is coming from there's not a whole heck of a lot one can do. There are no wear parts of the Tip. There is the fluid and filter and that's about all the servicing one can do. I do agree with the "valve body or servos filling up" diagnosis, sort of, without being able to offer a better one. It does sound like fluid rushing from someplace under high pressure to someplace else. That's unusual, to state the obvious. That the transmission appears to operate just fine though I have to wonder if perhaps that man made gasket has failed and instead of an external leak this time the leak is internal? That's all I got.

Thanks Macster, I knew you would come through :-) In fact, I posted yesterday about a slow oil leak/seeping from the transmission oil pan. https://rennlist.com/forums/996-foru...n-leaking.html I suspect if the oil pan isn't tighten correctly/gasket leaking it might introduce a not very tight compartment causing outside air to get in to the system. The only way to get to a tip/gearbox specialist would be through the indy as this is a small town, and it's easier to get referral from them.

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I've not seen the insides of a Tip. But I've seen the insides of a Chrysler automatic. It is rare that a gasket just seals one thing, like the pan. If the gasket is leaking to the outside it can be leaking internally, too. The leak is probably not due to the pan being tightened correctly. Well, this is a possibility but more likely would be the home made, tech made gasket is at fault. It is up to you -- and after you consult with a trusted Tip repair shop - but it might be worth having this leak addressed ideally with a real OE gasket and not one fabricated, unless this is the only way as the OE gasket is no longer available. At the same time another proper Tip fluid service would be done with I must stress full attention paid to doing this right. If the above doesn't then have the noise gone then I think you are faced with something more involved regarding the Tip. Your trusted Tip shop should be able to advise you what this might be.

Thanks, got appointment with the indy next Wednesday, we'll see what they say...