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Have you considered changing out the Tiptronic ECU. They are cheap as they dont seem to fail much but from a simplistic way a good place to start perhaps before diving into the pulling of valve bodies. The Tiptronic ECU is in the back hatch area on the passengers side behind the wheel well and side carpet. These cars also suffer a number of electrical gremlins surrounding bad grounds. Maybe also check the grounds in that area on the car as well. If you wanted to go this route to check the ECU I have a couple of them and would be happy to lend you one for testing if you pay the shipping each way. If so send me a PM with your address etc.. Probably $10-15 shipping unless you want 2 day service or something. Good luck with your troubleshooting.
Have you considered changing out the Tiptronic ECU. They are cheap as they dont seem to fail much but from a simplistic way a good place to start perhaps before diving into the pulling of valve bodies. The Tiptronic ECU is in the back hatch area on the passengers side behind the wheel well and side carpet. These cars also suffer a number of electrical gremlins surrounding bad grounds. Maybe also check the grounds in that area on the car as well. If you wanted to go this route to check the ECU I have a couple of them and would be happy to lend you one for testing if you pay the shipping each way. If so send me a PM with your address etc.. Probably $10-15 shipping unless you want 2 day service or something. Good luck with your troubleshooting.
Update 13 May 24.
I had to put the project on hold for several months as I worked thru some health issues.
On Saturday the 11th, a friend who is well versed in transaxle cars spent 5 hours with me as we R&R'd the old transaxle and installed the "new / used" transaxle.
With his help, the process went smoothly (having a lift and a lift table did not hurt).
The trans is now filled with fluid and seems to work.
I'll install the axles and take it for a test drive later this week.
Yes, I'm R&Ring the fuel filter also and fixing a torn CV boot
Stupid question but transmission problems following a 6 hr high speed drive makes me wonder if 10-15 year old transmission fluid couldn’t be the problem? I have a buddy who made a career out of buying 99-2010 Mercedes with “transmission problems” and solving them by replacing the Autozone crap with OEM MB fluid. Benz’s are notorious for this issue, but it’s made me a believer of a complete fluid change on every vehicle I ever buy. Brakes, coolant, PSU, oil.
Stupid question but transmission problems following a 6 hr high speed drive makes me wonder if 10-15 year old transmission fluid couldn’t be the problem? I have a buddy who made a career out of buying 99-2010 Mercedes with “transmission problems” and solving them by replacing the Autozone crap with OEM MB fluid. Benz’s are notorious for this issue, but it’s made me a believer of a complete fluid change on every vehicle I ever buy. Brakes, coolant, PSU, oil.
That was NOT the cause / fix in my case.
As I dug thru service records, the PO had tried this route at least 2X before listing on BaT.
Cheers
I won't go into detail, but after discussion with the seller and BaT, we agreed on a satisfactory resolution to the transmission issue.
I will say that BaT far exceeded my expectations and I give them Kudo's for EXCELLENT customer service.
I’ve never had to deal with an issue regarding a purchase at BAT, but my understanding is they are very accommodating if/when the seller misrepresents the car (purposely or maybe accidentally). Glad you were able to get some satisfaction.
I hope you get all the issues worked out, they are fantastic cars.
Initial testing is positive.
the trans selects all 4 speeds now, both automatically and in tippy mode.
I still need to take it for a longer drive, but I'm hopeful.
Connecting trans cooler lines = NOT FUN! Connecting trans cooler lines = NOT FUN!
I've been a busy boy.
~ 2 weeks ago I had a "catastrophic" coolant failure (while I was at the gas station fueling and celebrating the transaxle swap success).
It turned out to be a heater disc valve that basically failed at the adhesive joint.
While I was in there I:
Installed a new Cam Position Sensor and mating 3 pin connector to resolve the crumbled to dust 3 pin connector at the distal end of the CPS harness.
I installed a new knock sensor #1.
I took the cam / valve cover off to ease access to the CPS, so I installed a "valve cover gasket set deluxe" https://944online.com/valve-cover-ga...et-968-deluxe/ from 944 online to brighten up the cam cover washers. I also bought a few new fasteners to replace the ones that I struggled to remove due to fastener head rounding.
I also inspected the cam lobes, valve springs and cam chain tensioner pads to ensure nothing obvious was wrong.
Maybe most importantly I confirmed that the balance shafts were correctly timed. The PO had R&R'd all associated hardware ~ 2500 miles ago, but my local transaxle guru felt that they were not timed correctly (he noted a vibration @ 3500 RPM.). Good thing I checked. Timing was not correct. I'll try to add an image below. I followed the info from the WSM and this site https://www.924board.org/viewtopic.php?t=38866 to time the pulleys. Initially it was daunting, then as I dug into it, rather easy.
I installed new balance belt pulley fasteners ($2.00 each) since the previous "mechanic" had rounded the edges.
I changed the Oil and Filter since the filter was so easy to access.
I installed a new Porsche upper radiator hose. The PO had cheaped out and installed a piece of crap URO hose that rubbed the alternator pulley.
I installed new Porsche hoses on either side of the failed disc valve.
I stopped there, since I want to drive the car and further test the transaxle.
Here is a drawing of original balance shaft timing. I ended up rotating the lover shaft ~ 110 degrees CW to enable the timing mark on the pulley to align with the timing mark on the cover.
I made a Rookie Mistake when after timing the balance shafts when I installed the power steering and AC / ALT belt.
When re-installed they shrieked at every cold startup.
I re-checked belt tension and all seemed well.
I did a bit of reading and realized I had not "taken note of original rotational direction" when removing the belts.
I have no idea if I re-installed correctly of incorrectly as compared with original rotational direction.
so
I installed new belts and now all is quiet as it should be.
Cost me $45 and 90 minutes.
removed faded / yellowed paint protection behind the front wheels
I took advantage of the hot sunny weather and removed the faded / yellowed paint protection film behind the front wheels.
I let the car sit in the sun and 90 degree heat for an hour.
Both strips came of in < 2 minutes, passenger side in 3 pieces, drivers side in 4 pieces.
Back to the shade and let the car cool so I could remove adhesive residue with this.
Very easey peasey when working with hot / pliable vinyl
I took advantage of the hot sunny weather and removed the faded / yellowed paint protection film behind the front wheels.
I let the car sit in the sun and 90 degree heat for an hour.
Both strips came of in < 2 minutes, passenger side in 3 pieces, drivers side in 4 pieces.
Back to the shade and let the car cool so I could remove adhesive residue with this.
Very easey peasey when working with hot / pliable vinyl
No paint came off when you removed the adhesive residue?
Those adhesive protection pieces only last a few years.
04-27-2023, 07:14 AM
