valley996

I bought a Durametric for my 1999 996 C2. The problem I have is understanding what the actual values are? Where do I look to see what is "normal" after I check my actual values. I can't find anything on the Durametric cd or website. So far it's a bunch of numbers with no meaning. Any help?

What determines when the torque converter locks and unlocks? When does it lock or unlock?

Check the following link. I made my own filling tank and hose from the instructions in the DIY tutorials. It cost me about $20 and worked great. Hope this helps.

What is strange is that it does the surging while just cruising, not when the car is in need of a shift. I can go to manuel tiptronic and force it to stay in a gear at that rpm and it still surges. Would this still possibly be the torque converter? It also does it in all the gears as long as it is that particular rpm range. It does get worse as it is pulling a hill.

Hope yours is more dependable than mine! Start a Porsche savings/maintenance account!

I can't find an answer at all. I have about 20 different opinions so far. I bought the Durametric and it is nice, but there is nothing to tell you what the readings and values should normally be. What is normal voltage? What is the correct reading for the O2 sensors? What is the correct timing? I can't find anything from Durametric to help out on this. It's like having a brand new book written in Chinese and I can't read Chinese! I have had everything suggested (and I appreciate them all) from torque converter, spark plugs (replaced), MAF (cleaned and checked), TPS (replaced), fuel filter change (may have helped some), serviced the transmission ( may have helped some), checked for vacuum leaks (none found). I am afraid to go ahead and replace the torque converter, because that is going to cost me at least $2,000. This was my dream car and I was so excited to have a Porsche and I have yet to enjoy it. I am thinking I have made a mistake at this point. So far I have spent around $1500 and no fix! Anymore ideas out there. I can't even sell it at this point!

My mechanic suggested my 996 surging problem is the car running too lean. He said it is commonly referred to as a "lean surge". He said this is a problem with BMW and Mercedes as well. Has anyone heard of this?

Loren, Alright, I got my car back from the mechanic today. He changed the plugs and it 'may" have helped a little. He says what is causing my problem is the car is running too lean. He says most likely it is the coolant temperature sensor. He says the sensor is too sensitive and he can adjust the sensor by changing the resister in it. He said he has fixed this same problem on BMW, Mercedes and Porsche. He says the problem gets worse as the car gets warmer. I have not paid attention to this enough to know. He added Techroline to the gas to clean carbon out. He also said the combustion chamber can get allot of carbon build-up in it thus causing the car to run lean. I did clean the throttle body and there was no change. Does this sound like anything you have heard before? Also, will my Durametric tell me anything about this? Thanks

Loren, Will you look over the Durametric readings and see if anything looks bad. Do the O2 sensor voltage look right? Thanks 996.txt

Okay, I did my final flush of the transmission, changed the oil and replaced the fuel filter. I drove the car afterwards and the surge is still there but it is only half as bad as it was. There were numerous bubbles in the fuel that came out of the filter. I assume that was water. I am still lost on the total solution. I do have to replace my motor mounts, the right spilled out the fluid yesterday while I had it up. Loren, I will post my values today, so if you don't mind looking them over, I'd really appreciate that.

Thank you. I'll check it.

Loren, I got my Durametric today. I hooked it up and had no codes. Can you give me an idea how to capture the reading that you suggested. Thanks Is there an option for both of these on the Durametric? 1. Check the throttle potentiometer using Durametric, PST2, or PIWIS tester. 2. Likewise check the operation of the VarioCam actuation.

Loren, I got my Durametric today. I hooked it up and had no codes. Can you give me an idea how to capture the reading that you suggested. Thanks 1. Check the throttle potentiometer using Durametric, PST2, or PIWIS tester. 2. Likewise check the operation of the VarioCam actuation. VarioCam To increase the torque and to improve cylinder charging, the engine has two VarioCam actuators which are installed in the chain tensioners of the camshafts. The two actuators are operated by electromagnetic valves activated by the DME control unit. Functioning When the ignition is switched on, the electromagnetic valves of the camshaft adjusters are supplied with positive potential. If the engine is started, the control unit applies ground to terminal 25 (camshaft adjuster for cylinder line 4 - 6) and to terminal 52 (camshaft adjuster for cylinder line 1 - 3) if the following conditions are fulfilled (VarioCam activated); 1 - Engine oil temperature between -3°C and 133°C 2 - Engine speed > 1,300 rpm 3 - Throttle opening > 5% -or- 1 - Engine oil temperature > 133°C 2 - Engine speed > 1,480 rpm 3 - Throttle opening > 3.9% The ground potential is deactivated by the DME control unit (VarioCam deactivated) if: Engine speed > 5,120 rpm

I know, the more people I talk to, the more say it is a torque converter. I was just in hopes that it would be a little cheaper fix. Does anyone know if it is the torque converter, does the transmission usually stay in decent condition? Can I mostly likely get by with a torque converter only or do I need the rebuilt tranny with it.

Do you think I should replace the throttle position sensor? Also, I will have some numbers from the Durametric this week. Again, thank you.

I should say the car appears and feels like it is shifting okay. I would note that when I pull out fast and floor the gas it shifts smoothly and there is no missing or rpm fluctuations. It's only if I am cruising in that rpm range (1500-2500) or especially when pulling a grade. Also, if I am in the manual tiptronic mode it does it in all the gears in the same rpm range.

I'll do that. I ordered a Durametric yesterday. It will be here Wednesday. I really do appreciate the help. Based on your experience does it sound like it could possibly be the torque converter? I am hoping it is not, because that is an expensive fix!

Loren, I cleaned it and it moves better, but not what is causing my problem. Any more thoughts or suggestions I can work on?

I am asking for help again. I am thinking this may not be a transmission issue. What is happening is the car rpm's are jumping up and down as if I am pressing the gas pedal and letting off, but it is doing it on it's own. I does get worse on a grade. It does it while crusing between 1500 and 2500 rpms, when the car has no need to shift, which leads me to believe it may not be a transmission issue as was though early on. I can use the manual mode of the tiptronic in all gears and it does it in that range. Note: If the car is in Park, there is no problem in that same range when I rev the engine, it's only when moving. Also, as a reminder I have no codes with the PIWIS or Durametric tester. What I have done so far with no changes: 1. Cleaned the TCV ( very dirty, also looking inside of it the flap that opens and closes is not fully opened or closed. Is this normal?) 2. Unplugged the MAF and drove, no changes 3. Cleaned the throttle body. I am sorry for being a pest, but this is driving me crazy. Thanks

Please disregard. I found the topic in the tutorials. Very good instructions.

I have a rattle inside my 1999 996 drivers door. The window also squeaks when going up and down. I am concerned about removing the door panel because of the airbag. Does anyone know how to do this safely? Thanks

Loren or anyone who may be familiar, Can I ask you to watch this video of an Audi A4 with the EXACT same problem as mine? Especially at 1:08 into the video. I just don't want to replace a transmission if I don't need to, and It may turn out to not be a transmission at all. I appreciate any help or suggestions at this point. I just don't want to sink a fortune in a rebuilt transmission and not need it. Thank you

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.

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.