Tipronic transmission gear slips

[zft325]

HI guys im new in this forum, I have a 2001 boxster S the car runs great except sometimes when the gear shifts from 2nd to 3rd i experience a sort of slip(the Rpm goes high and the car dosent move until 3000rpm) i changed the fluid still the same. This also happens sometime if im in slow trafic going from 2nd to 3rd shifting. can anyone help me with this problem? it feels like when your being a clutch driver on a manual transmission thanks :huh:

[jimyboyle]

Mine's is a 1997 2.5 and does exactly the same. Also changed the fluid to no effect. I am sure there is another post somewhere on the site saying it is a quirk with the box and not a desparate problem. Still annoying though, for some reason mine does it on the same section of road, coming uphill to a roundabout near my house , slow down and as you try to move off the engine revs shoot up and then it engages with a clunk. Perhaps connected to the enging loading on the hill. Maybe it just does not want to go home.

Jim

[zft325]

hi jimmyboyle, yup we have the same problem. i hope someone from here with an experience can help us. its really annoying, i have a mechanic look on it and according to him there is probably a valve or something thats not working properly. btw where are you from? im from the Philippines and as you know we only have one dealership here. most of the indy shops have no experience with porsche's repair. ive been looking for a thread on this matter but cant find any here.

[Loren]

You need to find a shop wiht a PST2 or PIWIS tester and have them run the Tiptronics diagnostic program and check for faults.

[zft325]

hi loren you think its just faults in the ecu?

hi im trying to check also on other porsche model if they experience the same problem

[Loren]

There are very good diagnostics for the Tiptronic transmissions used on 9x6 series Porsches.

The Tiptronic has it's own control unit separate from the engine ECU. A 5 minute test with a PST2 or PIWIS tester will tell you what if anything is wrong with the Tiptronic transmission. It will tell you if there is (or has been) a stuck valve or even if the fluid level is low.

Any other diagnosis is just guess work.

[zft325]

ok i will look for a shop who has that and will post results, thanks. still waiting for a kind soul who may have had that problem:) hehehe

[Loren]

ok i will look for a shop who has that and will post results, thanks. still waiting for a kind soul who may have had that problem:) hehehe

Sorry, it's not that simple - even the same symptom can be different problems - so on one car it may be low fluid level and a bad valve on another.

[zft325]

update on the diagnostics, everything is clear. no fault. the fluid level is just right on the level. i will get another diagnostic next weeek. i think i need another opinion

[airfighter]

When you stop, is the engine going to stall? My problem started as yours, then the engine started to stall 2-3 times when i was stopping, and finally the car came to a complete stop. I had to overhaul the tranny, in an independent mechanic, for 4000 euros (1 year warranty, from him) . Porsche dealer, here in Greece, wasn't helpful, cause they told me that the only the can do is to take the damaged tranny and put me an overhauled by Porsche for... 8000 euros (with 2 years warranty)!!!

So pay attention to it, i really feel ugly...4000 euros today is equal with $US 5700.

[zft325]

wow thats a price to pay for an overhaul, anyway if your asking if my engine stalls? nope. not at all its working fine and no problem,its just the transmission. i will now try the valve. i will let an expert in transmission take a good look at it next week. will update you. still looking for someone who might know the problem. thanks

[carlosvquezada]

My transmission does the same thing between 2nd & 3rd. I have noticed this does not seem to happen when I drive the car harder. I.e. when my foot is heavy and the shifting program takes my RPM's up higher before changing gears the problem seems to go away. Like someone said earlier it feels almost as if you were driving a manual transmission and shifted to too high a gear for your speed.

Further, when I am finger shifting (and thus usually taking the car to higher RPM's) I don't notice the problem either.

One thing I did notice (and was wondering if anyone had as well) was that when the transmission shifts from 2nd to 3rd gear the car seems to throttle up without me pressing down any harder on the pedal. As the transmission shifts from 2nd to 3rd, the RPM's will go up about 500-1000 RPM.

1998 Boxster 2.5 Tiptronic US

1978 Catalina 22

Edited August 22, 2009 by carlosvquezada

[Alex Walker]

Same problem on my 97. Aggravating as hell.

[zft325]

hope we can get answers on this thread:) im hoping guys, well atleast i know its almost a common problem.

[Alex Walker]

No more info here?

[JeTexas]

I've never been inside a tiptronic, so I'm not completely sure of how they work, but in your generic automatic transmission there's bands. If a band breaks, you lose that gear.

A quick, generic explanation from http://www.familycar.com/Transmission.htm#...on%20Components

Bands - A band is a steel strap with friction material bonded to the inside surface. One end of the band is anchored against the transmission case while the other end is connected to a servo. At the appropriate time hydraulic oil is sent to the servo under pressure to tighten the band around the drum to stop the drum from turning.

It could be that the friction material on that band is worn. It could be that the band just needs adjustment. It could be that it's on it's way out completely.

That's just my guess though. Like I said, I've never seen inside a Tiptronic, and I haven't worked on an automatic transmission since the mid-90s.

[zft325]

its with an indy shop now, ill update you. really cant stand that slip.

[Alex Walker]

I was planning to do the same. I'll be interested to hear what they say and how much $$$. Thanks

[zft325]

ok, i get alot of opinions from porsche ppl here. heres what i heard from them since i started on this transmission problem venture. 1. something to do with a valve inside the tranny, 2. a problem with the gear orings and clutches, 3. try to run it temporarily on manual mode(using tiptronic only) for several hundred kilometers. btw ive tried changing the trans fluid which is soooo expensive! so i guess that ruled out the fluid issues. anyway its in the shop and im awaiting for their diagnostic on the problem. i hope they get it this time or else ill just buy a new tranny just to get rid of this irritating problem, any of you know whether the tranny of the regular boxter matches on the S version?

[wvicary]

Before going to great and expensive lengths like changing the transmission, is there any chance you could test drive a another vehicle to see if it displays a similar fault. If the fault doesn't occur in manual mode but only the odd time in automatic mode then the mechanical portion of the transmission should be sound.

In my experience when a component fails inside these units it stay failed, not operating correctly some of the time and then fine again. When a sealing ring for the clutch pack or friction material is broken/worn it's finished and displays the same fault all of the time. Sticking valves will cause intermittent problems as will the pump and are much harder to fault trace. It could be a fault in the software adaption.

If no codes are found I would verify the operation of the engine throttle position sensor and readapt the transmission ECU. Disconnect the battery for a minute or two, re-connect, turn ignition key on for one minute without starting the engine, shut key off and then restart vehicle and road test. It's simple enough to complete and cost nothing. Just my two cents and my experience comes from the VW/Audi area. Hope this is of some help.

[Alex Walker]

Anyword from the shop on the tranny?

[carlosvquezada]

Before going to great and expensive lengths like changing the transmission, is there any chance you could test drive a another vehicle to see if it displays a similar fault. If the fault doesn't occur in manual mode but only the odd time in automatic mode then the mechanical portion of the transmission should be sound.

In my experience when a component fails inside these units it stay failed, not operating correctly some of the time and then fine again. When a sealing ring for the clutch pack or friction material is broken/worn it's finished and displays the same fault all of the time. Sticking valves will cause intermittent problems as will the pump and are much harder to fault trace. It could be a fault in the software adaption.

If no codes are found I would verify the operation of the engine throttle position sensor and readapt the transmission ECU. Disconnect the battery for a minute or two, re-connect, turn ignition key on for one minute without starting the engine, shut key off and then restart vehicle and road test. It's simple enough to complete and cost nothing. Just my two cents and my experience comes from the VW/Audi area. Hope this is of some help.

As I've mentioned in other posts readapting the trasnmission ECU alone seems to help. How would one go about verifying the operation of the engine throttle position sensor? Also, I've seen instructions (from Pedro's Garage I believe) for cleaning the throttle body. Do you think doing this might help the ECU adapt better and thus alleviate these shifting problems?

[zft325]

hi guys. just got my car at the shop. they tried to connect a computer while running the car and everything seems fine. no errors or whatsoever. tom i will bring it back on a different test. im still looking for answers. the technician said it might be a sensor, he will check tom. inform you whats next.

[carlosvquezada]

F.Y.I. - I wanted to let everyone know that two months since I first posted on this topic, I ended up blowing out the torque converter in my tranny I will now be having my transmission rebuilt.

I don't know what to suggest, since looking inside a transmission is not cheap, but thought it might be helpful for others to know. I would be curious to hear any updates from others who were having similiar problems.

Btw, KBL Transmissions in Midway City, CA quoted me a rebuild with a 1 year/12,000 miles warranty for $2,700.

[Alex Walker]

I've actually found that my slips have kind of subdued. They don't happen as often as they did back when I first posted about it. I'll probably end up having it checked out anyway just to be safe.