valley996

I have a 1999 996 C2 Tiptronic. I have to replace the transmission and I can't afford the Porsche Dealer quote of $8,300. Any suggestion or do you know anyone in Virginia or North Carolina that is good?

Make sure you really need to change the transmission. Tips do not frequently fail, but can exhibit symptoms of failure. I am not saying the shop doesn't know what they are doing, but just may not have that much exposure to Tips. It would be extremely hard to become an expert on Porsche Tip issues with very limited exposure.

Are there any codes? CEL on? There are numerous things that can cause problems that do not require a new transmission. As an example, pressure regulator 4 can fail causing a CLC lockup not to work. This could be interpreted as slipping since the converter doesn't lockup as expected (about a $500 fix).

Another example, if the brake light switch is intermittent, the automatic downshift does not work properly.

Yet another, if a wheel speed sensor fails (P1710 right front or P1715, left front), then your tip shift buttons on the steering wheel will not work I chased this gremlin through wiring diagrams, fluid change, harness check, etc. Finally found it reading the OBD II section on Tip diagnostics, which is over 100 pages.

After nearly a decade of metro traffic, I have only had the wheel speed sensor issue and intermittent brake light switch issue.

You do have options for a rebuilt unit out there with the updated ZF parts.

http://www.freddiestransmissions.com/html/zf_5hp19.html

http://www.europeantransmissions.com/

http://www.drivetrain.com/parts_cata...smissions.html

Please keep in mind, not all problems throw a light, but will produce a code.

Codes that do not trigger a light :

P0710

P0740 (note this code was thrown by faulty regulator 4)

P1602

P1656

P1704

P1710

P1715

P1744

P1761

P1762

P1764

P1765

P1770

P1828 (short to B+ only, short to ground throws a light)

It is surging between 1500 and 2000 rpms. It does it in all gears and is smooth above or below the rpms. It gets worse pulling a hill. If I am in park and rev the engine it is smooth. It's only while pulling. Here is what the Porsche mechanic said. He said the main line pressure for transmission fluid control loses pressure on and off which is a sign of a weak solenoid. He suggests to replace transmission ( I can't afford!) also, he says I can replace valve body or individual solenoids. Does this sound right?

1. He did a 89757 internal malfunction test with piwis tester - none registered.

2. fluid level - good.

3. tested MAF - good

4. tested for power and ground on TCM module - good

5. removed torque converter lock up wire and test drove- good

6. checked fuel pressure - good

7. no codes in vehicle

8. solenoid circuits are intact and complete

9. no codes on Tiptronic test.

Diagnoses: He said the main line pressure was checked with a piwis tester and it it showed the main line for transmission fluid control loses pressure on and off which is a sign of a weak solenoid. I would like to rule out an easier fix before I spend $5000 for a rebuilt transmission.

I'm interested to see what you find out. I have a similar problem in my 2000 C2 tip. When running in 5th on usually smooth surface I detect the engine RPM move up about 300 - 500 or so. Not quite a full downshift. The shift indicator has not changed. I have 86 k miles on this car and it is my daily driver. I had Autobahn Porsche in Fort Worth replace the fluid at ~ 80k. They said they scanned the car and no problem noticed (if they actually did it). I purchased a Durametric scanner and no codes come up for the Tiptronic. El Acura, did you get any codes to tell you it was the solenoid? I do not have a CEL light.

Hello GranburyChuck.

I didn't have any cel light, and no particular code for the solenoid problem.

The solenoid was working, but was working very very slowly = poor shifting...

The low tranny fluid cause high engine rev and miss shift between 4th and 5th gear

due to the high volume of transmission fluid needed at high speed.

Good luck

I am hoping you can help me. I read your post about the slow solenoid in your Tiptronic. I believe I am having the same problem. I have posted the topic on here under the 996 section as a "surge between 1500 and 2500 rpms. I have had all tests and no CELs. Three mechanics say it is a transmission problem. The Porsche mechanic felt is was a slow solenoid not doing it's job, but not enough to not throw a cell. What did you conclude on yours? Can it be fixed or does the whole transmission need to be replaced?

Does the whole transmission have to come off to replace. I want to rule out as much as possible, before I spend $5,000 on transmission. I really don't want to lose that money and it turns out to not be the problem. Thank you so much for the suggestions, I'm just really lost and don't know what to do at this point.

I assume they checked the Tiptronic fluid level?

Any difference going uphill or downhill?

Fluid level was good. It is much worse going uphill, almost nonexistent going downhill. It does it in all gears if it is in the 1500 to 2500 rpm range. It is smooth above 2500 or below 1500rpms. It does not miss while in park and revving the engine.

I assume they checked the Tiptronic fluid level?

Any difference going uphill or downhill?

They did and the fluid was good. It does get much worse going uphill and almost nonexistent going downhill mainly because I'm not using the throttle or no load on the transmission. It does it in all gears.

Loren,

I found out today the Porsche mechanic did not run the Tiptronic computer test. Could we be missing something by not running the test or would it show up anyway on the main computer check?

Thanks

Yes, that is why the test is there.

Run the Tiptronic tests and you might be lucky and it tells you exactly what is wrong.

Loren,

Nothing on the Tiptronic test. Could this not be a transmission problem? It is smooth while in park revving the engine, but it surges while in gear and moving. Could it be an ignition issue, coil pack, etc?

Thanks,

Aaron

Oklahoma Foreign lists a 99 tip with 50k miles on it for $3000.

Have you spoken to any local indy shops in your area for advise? They may be able to assist.

I have no personal experience with Vertex but know they have been selling Porsche stuff for a long time. I have a 99 tip and if I had an issue I would probably go that route.

Good luck with this issue.

Thanks for the advice. Could the mechanics be completely off and it not be the transmission? It is smooth while in park, but when moving that is when it acts up. I had one person say it could be a coil pack. Is this a possiblity?

Did you look at Vertex. I believe they sell re-man Tips.

I have and I called them yesterday. Does anyone have any experience with them. The cost is $3300 for the transmission. Then I'll have uninstall and install locally.

I had the Tiptronic test done today and no codes. I am at a loss. I am considering a rebuilt Vertex transmission. Anybody have any experience with them?

I would give Oklahoma Foreign a call.

They might have a low milage one in there yard.

http://www.oklahomaforeign.com/

Paul

thank you

I have a 1999 996 C2 Tiptronic. I have to replace the transmission and I can't afford the Porsche Dealer quote of $8,300. Any suggestion or do you know anyone in Virginia or North Carolina that is good?

Loren,

I found out today the Porsche mechanic did not run the Tiptronic computer test. Could we be missing something by not running the test or would it show up anyway on the main computer check?

Thanks

Yes, that is why the test is there.

Run the Tiptronic tests and you might be lucky and it tells you exactly what is wrong.

I really appreciate the advice.

I think the popular opinion is that with stock rim width (7 & 9) you can go to a 225 front and a 275 rear. I was considering doing this until I purchased a set of 18's

Check out Tire Rack as the spec section gives a rim width range for each tire size and you can also talk to their customer service guys. They are pretty knowledgeable.

I really appreciate your advice and time.

Loren,

I found out today the Porsche mechanic did not run the Tiptronic computer test. Could we be missing something by not running the test or would it show up anyway on the main computer check?

Thanks

In need input into tire size I can put on my stock '99 996 wheels...I've got 17" wheels right now with 205/50/17 in the front and 255/40/17 in the rear. Front = 7 J x 17" 55mm offset Rear = 9 X 17" 55mm offset. The front tires look small, but the rear looks good. What size tire can I put on the front to make it look taller, but not wider?

Thanks

Yes, the Tiptronic has a bunch of solenoids.

thank you

PIWIS is a Porsche diagnostic tester and tool. It is custom for Porsches and can diagnose many faults as well as rule out false problems.

Loren,

Does this possibly sound like a solenoid problem?

Thanks

I can't answer that. What is piwis? What are thoughts about it?

Here is what the Porsche mechanic said. He said the main line pressure for transmission fluid control loses pressure on and off which is a sign of a weak solenoid. He suggests to replace transmission ( I can't afford!) also, he says I can replace valve body or individual solenoids. Does this sound right?

1. He did a 89757 internal malfunction test with piwis tester - none registered.

2. fluid level - good.

3. tested MAF - good

4. tested for power and ground on TCM module - good

5. removed torque converter lock up wire and test drove- good

6. checked fuel pressure - good

7. no codes in vehicle

8. solenoid circuits are intact and complete

Diagnoses: He said the main line pressure was checked with a piwis tester and it it showed the main line for transmission fluid control loses pressure on and off which is a sign of a weak solenoid.

Is this possible and what is the cost of a repair?

I would also recommend a dealer visit. Can you feel it dropping out of gear?

No it doesn't drop out of the gear, it just surges while in the gear. It does it in all gears as long as it is in that RPM range. It also gets worse when it is climbing a grade.

Does the car have an electronic throttle? - if so, problem may be linked to carbon build up in the throttle body - not difficult to clean yourself...

I don't know about electronic throttle. I took it to a garage today and he said it was most likely the transmission. He referred to it as the car looking for a gear while in the 2,000 rpm range. He noted that if it was climbing a grade it became worse. He received no error codes so he felt it was mechanical. He recommended going to the Porsche dealership to rule out a software problem. Any thoughts?

You might not have a check engine light but there might be codes in the system. I would have the DME and transmission checked for codes first.

I have it scheduled in the morning. I'll post the results. Thank you for the suggestions. It's my first Porsche!

I have a 1999 996 carrera tiptronic and it has a surge in engine speed between 1500 and 2200 rpms. The tac and engine speed goes up and down, in a steady rhytm. It does not do this while in park at the same rpms. Also, when I am in that range and I mash the pedal there is a stutter, almost like a miss. I know this is hard to explain, but there are no check engine lights. It does this in all gears in the same range. It is smooth below and above the range I have listed. I need help!