Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
10/31/20 1:10 p.m.

So close, so, so, so close.  

After the prior updates I got it all back together and fired it up.  Well, when I say fired it up it was only for a few seconds at a time.  Why?  Well for some reason, and I damn well knew I had a reason at the time, but I'd like to go back and slap past me up side the head.  I decided before putting the transmission in the car to only fill up the diff and not the transmission itself.  Why the hell I did I really can't figure out as you need to put in 9 Liters of distilled unicorn blood.  The thing is as these sold as sealed for life, there's no easy way to fill them.  You need to pump the fluid in from underneath through this little castle like thing.

Nine Liters is a lot to pump in what feels like one table spoon at a time with this, while under a car that's only 18" in the air.

Also as you can see with the pan above, you can only put a small amount in at a time before it comes out.  So I had to fill the pan, start the engine for 30 seconds so the oil would pump around, but not harm anything.  Then stop it and repeat.  So I spent the last week doing that. 

So now it's full I let the engine really warm up and pump everything around having not been run in over a year.  Then came the next issue.  Once a thermostat opened in the trans cooler circuit, it's shared with the engine coolant, water started coming out from underneath.  Now the trans fluid is distilled unicorn blood, the coolant is pure unicorn piss, but being an idiot who wants to keep his very expensive engine working,  I use the real Porsche stuff.  Anyway, I can find where one end of the hose attaches too, but not the other.  So it's my regularly scheduled call out to AAZCD.  Dude, where does this head too?  I do have the hose, I just can't figure out where the other end goes.  

NOTE.  Don't leave it ove a year after taking something apart before putting it back together.

Here's a pic.  AAZCD will recognize the location, but for mere mortals, this is looking down and back from above the left hand bank of cylinders. 


AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
10/31/20 2:18 p.m.

I'm away from the office at the moment. Nice day for a Fall foliage flight.  Gimme about an hour or two and I'll have a diagram.

AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
10/31/20 4:22 p.m.

Here's your picture:

EDIT ***Labels corrected and pictured from my 2001 Tiptronic parts car. -The wiring harness is removed so it does not obstruct part of the view.

Check this tech article figure 2 for a different perspective:

Is that what you needed?  ...or are you talking about the coolant lines to the transmission cooler?

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
10/31/20 6:49 p.m.

Oh crap, so it's literally the overflow!! It's meant to cone out of there!!

Ever felt dumb?  I have. Like now. 

AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
10/31/20 7:01 p.m.

In reply to Adrian_Thompson (Forum Supporter) :

Well, yes. I feel dumb now. I just looked at a parts car and saw that I labeled the hoses wrong.

The bottom one that you asked about is the drain and dumps by the wheel.

The others are now correctly labeled in correction #3 posted below and now replacing the previously posted picture. (final edit)

AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
10/31/20 7:24 p.m.

While I was taking pics, I got this too. Two coolant lines go from the front right of the engine back to the transmission. They mount just above the sump plate and have a short piece of hose to connect to the metal lines on the transmission. Here's a pic of where the are at the front right of the engine:

I think you have that part figured, but might as well post. Best of luck on a nice drive in the next few days.

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/1/20 1:03 p.m.

I think I have the cooling system buttoned up and all working.  I'm not properly bleeding it yet as that means dropping the nose to get the correct angle, and I want everything buttoned up underneath first.  I'm not putting the under tray and braces on until I know it's all done.

So that brings us to todays question.  With the engine running, in park, the trans indicator lights for '4' and 'P' are flashing alternately.  I can put it in Drive (interestingly I don't need to press the brake so the interlock isn't working) it does engage and the wheels do go round.  Pressing the accelerator in drive does increase the speed of the wheels and you can read the speedo.  But unless I'm not revving it high enough, it's staying in 1st.  Obviously the steering wheel buttons aren't working either, regardless of moving the lever into S.


AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
11/1/20 2:43 p.m.

I have not had that one yet. I'll see if the shop manual has any insight tonight. For now, I'd start with simple stuff: Wiring connections to the transmission snug and clean -  main harness and gear selection switch (near the end of the shift cable). Fuses (B1), (B8), maybe others. Ground wires - without looking, I'm guessing there's just a harness ground in the trunk. There may be another.

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/1/20 4:08 p.m.

That's a good start. I'll look tomorrow. Thanks

AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
11/2/20 7:22 a.m.

I forgot to check the manual last night, but I did remember one thing. I had that happen once when the battery was really low. Your car sat for a long time and if the voltage is down in the 11.x volt range it may be too low when the TCU powers up.

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/2/20 7:27 a.m.

In reply to AAZCD (Forum Supporter) :

Battery was low, but it's been on a battery tender for the last week so I don't thinki its that.

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/2/20 5:25 p.m.

So, been and checked things and ran it again.  

  • Battery is 13.2V
  • I don't see any unplugged harness connections.  Every connection I can see I've also pushed together to make sure it had clicked home, they all had.  The only issue I found was the inlet air temp sensor wasn't fully seated, so I may have saved myself a future issue there!
  • Shifter cable is connected and the sensor moves as the shifter moves the input.
  •  It still alternately flashes '4' and 'P'.  I do see that when you move the shifter it flashes '4' alternately with P, N, R, and D which does correspond correctly with the actual gear the trans is in.
  • All fuses are good.  Well two were blown (B2 7.5A Radio and C8 30A Rad fan RHS) but neither were relevant to this.  

Is there a layout of connections so I can make sure I've located them all?

Is there a diagnostic for the shifter sensor (the rotary selector, not sure what it's called) so I can make sure that's giving the correct output?  Although the fact the correct light flashes as above.

I guess I should trouble shoot the brake interlock isn't working.  Could that contribute?  Any ideas how?



AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
11/5/20 8:36 a.m.

Was the brake interlock working before? I remember that you went through some shift lever issues earlier.

I've been looking through the factory service manual (Group 0 Diagnosis, Part 1) and it is written for use with a 'Porsche PST2' diagnostic tester. It doesn't look like much help unless you have a code reader that can give you transmission fault codes. My Autel MD802 can do that, but most of the simple code readers probably don't.

I don't know how much help it would be, but I can email you pin-outs and wiring diagrams, which may also be available in the back of the Bentley manual.

For true technical assistance, you could try posting at "" or message "JFP_in_PA" there or on the 986 Forum. Most of JFP's posts are not very verbose, but he is Always Correct and usually very patient.

Tom_Spangler (Forum Supporter)
Tom_Spangler (Forum Supporter) PowerDork
11/5/20 8:59 a.m.

Ade, I have the Bentley manual if you want to borrow it.

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/6/20 10:25 a.m.

So it looks like I can access to a Porsche scanner this weekend so I'll do that.  I believe there's a procedure for the multi function switch on the side of the trans.  I need to see at least that portion of the Bentley manual if possible.


AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
11/6/20 11:29 a.m.
Adrian_Thompson (Forum Supporter) said:

 I believe there's a procedure for the multi function switch on the side of the trans.  I need to see at least that portion of the Bentley manual if possible.

I just emailed a message with a link to pics that may be helpful.

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/6/20 1:17 p.m.

In reply to AAZCD (Forum Supporter) :

Got it.


Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/9/20 8:21 a.m.

OK, so progress has been made.  

Jeff (Gearheadotaku) came over with a iCarsoft POR II scanner from work.  It can't do everything, but we hoped it would help along with the info Jon (AAZCD) sent.  Tom Spangler (AKA Tom Spangler here!!) also popped over with Klienes Kabriolett his 01 Boxster S that he recently got and has done some work too.  HE wanted to check his cam phase timing with the same unit, which I think he and Jeff did while I was putzing around doing other things.

OK, so before the update here's my silver 99, Tom's green (outstanding color) 01 S and Jeff's trusty and reliable 00 V6 three pedal Firebird.

Anyway.  Cliff notes version of the next 2-3 hours.  First thing we did was hook up the scanner and try to read codes, for some reason that wasn't working well, but we did clear all codes and that made an instant difference.  Now when I started it there is no alternate flashing lights in P, R, or N.  Only when you put it in Drive does the 'D' light flash, and just on it's own, not alternating with '4'.  Despite several efforts to pull codes, it never did, but on jack stands everything except the flashing and light appeared to be working.  So then I set about putting wheels back on for a tentative test drive.  At this point I didn't put the chassis bracing or undertray back on as I was fairly certain I would have to remove them again.  Also being an incompetent ass I managed to start one of the wheel bolts cross threaded, so until I can clean up the threads I drove it with only four, not five bolts in one wheel.  With a lack of wheel bolt and no chassis bracing there was no hooning going on, just a careful drive around the neighborhood.  Good news.  The car shifts correctly and smoothly, although again no manual mode is available.  So back in the driveway it's time for some googling.   Despite the fact that we couldn't read codes, the almighty (and never wrong!!) Internet said that a flashing 'D' indicates P0710 code which is the internal trans temp sensor.  We'd already double checked the fluid level so we knew we weren't low or anything.  So with the car up on jack stands again, the scan tool could read the temp sensor, it was saying 78C (172F), which seemed suspiciously high for less than a mile drive.  Sure enough, when I grabbed a surface reading infra red thermometer and pointed it at the pan we were reading around 80F (27C).  After sitting idling a while the sensor still read 78C while the oil pan did get warmer.  So, back on the ground and another drive, this time a little further onto a road we could accelerate a bit, and with Jeff reading the scanner.  Yup, this looks like it.  A slight tip in or tip out could make it jump up or down as much as 30C (86F) in a fraction of a second then return.  Again once back in the drive and up on stands it was back to reading 78C while the pan read much much lower.  So right now it looks like its a relatively easy fix.  The temp sensor is part of the internal trans harness so that will cost around $130 to replace.  Here's a pic of it when I was changing the trans fluid and filter a few years ago.

On top of the trans issues I discovered I have some top function issues too.  One bushing is damaged on one of the arms and a 'C' clip has vanished so the right hand actuator keeps coming out.  So that's some more bits and bobs to fix.  

At least I was able to drive to the gas station with my wife and put in a couple of fresh gallons, so in total the car has now driven about six miles in the last 16 months!

So later today I'll start ordering parts and finally get this thing back on the road just in time to put it away for the winter.


Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/16/20 8:42 a.m.

Not sure how my little German soap opera is doing, I seem to be losing viewers, but this is still a log for myself as well.

So what's next in this little melodramatic drama of a simple trans swap?  Well last week I left off with the assumption that the temp sensor inside the trans was kaput.  I don't know if this should have been changed when the trans was re-built, but if not I can fully understand 20 year old plastic insulation and wires having been baked and cooled inumerable times inside hot oil could be brittle and break having been removed and re-fitted.  So I went to order a new one.  As with many Porsche parts the prices vary wildly from $135 to over $400.  I ended up paying $135 for a ZF part (the manufacturer of the trans) from ECS, who also had the 'genuine' Porche part (i.e. the ZF part in a Porsche plastic bag) for $375.  Easy choice!

So having walked away from the car for the week and been busy in the yard on Saturday with potentially the last of the nice weather, I got back to the car yesterday (sunday).  Well the oil pan on the trans is held on with lot's of t27 Torx button heads.  These are supposed to be tightened to 8lb/ft (11Nm) and I was carefull to do them to that a few years ago when I first got the car and changed the fluid and filter.  Well bugger, the guy who re-built it appears to have thrown them in with much uggie duggie action.  Those suckers were all tight requiring a solid grip on the ratchet and a solid 'click' when they broke free.  All but one of them.  This is worrying as the guy how re-built the trans only does auto rebuilds mainly for dealers and specialists, he should know better or just doesnt' care.  Anyway, the last one is trying to round out the torx and I can't get a grip.  I started this seperate thread and I'm going to buy some Tekton torx bits and borrow a manual impact driver.  That'll have to wait.

But wait there's more!  What I didn't mention last week is that while working on the car the other week I went to raise or lower the soft top and JEff and Tom noticed that a) a clip had come off one joint that held one of the rams in to an arm and b) a soft rubber bushing had disintigrated on one of the to ppush rod arms.  Note, these are not joints I touched when replacing the soft top material last year.  So I ordered the parts via Jeff at the dealer and since I was defeated by changing the harness decided to finish off the soft top instead.  It all goes easily until I'm comparing one side with the other and discover another issue.  And this one baffles me.  Stuck Convertible Top - Manual operation... - 986 Forum - for Porsche  Boxster & Cayman Owners

See the arm in the pic below part #4?  Well the bushing I replaced was #27 on the RHS.  When looking at the LHS for reference I noticed that the other end wasn't attached to anything and that the arm was laying down in a grive below another part.  Even more confusing is that the ball stud it's meant to attach to is simply missing.  In the two pics below the first is the RHS attached, the second is the LHS where the ball stud is missing.  Now I've got to get the part and figure out how to access it all.  This pic is taken with the top partialy down through a gap about 1 1/2" wide.  It turns out the LHS pick my phone was focusing on something else, but the ball stud is supposed to be inside the red circle.  

So more parts to order and more time.  Ho hum.

Gearheadotaku (Forum Supporter)
Gearheadotaku (Forum Supporter) UltimaDork
11/16/20 11:01 a.m.

The red plastic part is a common failure point, Porsche only sells the whole arm as a replacement. After market answers may be out there. The ball stud and nut are available, but yours may be rolling around in the drain tray or something. 

Can you ditch the power top stuff and use it manually like a Miata? May take extra steps to deal with the hard boot.

Leave it down and go true roadster? Shop for a hardtop? 

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
11/16/20 12:12 p.m.

Yeah, i think I'l order a new metal ball stud and aftermarket end piece, the plastic one is pretty chewed up.  

I'm not worried about getting the joint back together, it's access it to put the new ball stud on that I've got to figure out.

AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
11/16/20 9:05 p.m.

I have plenty of arms, but they may not all have good bushings. The plastic sockets are available on eBay and elsewhere for about $15 a pair.

What is your issue with access? You should be able to move the top by hand and get to any of the parts by disconnecting the rods and it sounds like most of yours are disconnected for you already.

Otherwise remove bolt (32) from the diagram that you posted earlier and the top will move freely. Here's a video showing how to do it. (Not saying you should convert to manual operation)


Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
12/7/20 10:46 a.m.

Sporadic update.  So I changed the harness inside the trans.  From the discoloration of the connects it looks like it wasn't changed before.  The problem is I still have the same fault.   'P' flashing when in Drive and inability to manually change.  So that still says it's the temp sender inside the trans.  I guess I should have changed that along with the harness.

Pic of valve body dropped showing the temp sensor and something else.

I'm so sick of this right now I may button everything else up and just store it until the spring.  My enthusiasm is entirely used up.

One thing, this is the pan after I pulled it.  That seems like a lot of forign material for a freshly rebuilt trans doesn't it?


Right now I feel like this could be a good next mod.

Famed 'Molotov Cocktail' has survived the test of time - Asia Times

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
3/15/21 9:24 a.m.

OK, so let's get this thing moving again.


Quick update of where we were. Last time I posted I had changed the harness inside the trans, but still had the flashing P light and inability to shift manually. I did putz around a bit after that and got to the point where I still had the flashing light but could drive in D or sport, and I was able to change gears manually with the steering wheel buttons again.  To tell the truth, I don't remember how I got to that point. That's why I should update this damn thread, not because anybody else has a really interested, but so I remember what the berkeley I've done!   So other than the flashing light, I just had the broken linkage in the soft top to deal with. By then it was mid December and freezing cold so I just put the car cover on in the garage and ignored it for the winter. 

Well now it's getting warmer and Tom Spangler has inspired me with the progress on his car, so I decided it was time to get this thing out and finished up. I got it uncovered and thought I'd take it for a drive but it wouldn't start. Now, a couple of years ago I had the electrical ignition barrel fail (Page 4 of this thread) which isn’t uncommon. I ordered a new one, but when it came one plastic tab was broken off. I installed it and it seemed to fix things but they had sent me a new replacement which I never got round to fitting. So I assumed it was just that that it failed so I swapped it out again for the new one. Unfortunately, this time it made no difference. Still no start. Nothing else has changed, and the last thing I did before putting it away for the winter was take it for a 10 mile drive and get some gas, so everything was working. I understand there is another fix that requires replacing more of the lock mechanism, including the part that goes to the steering column. Anybody know about that or have ideas?

Other than that I am now going to order the soft top parts , plus anything I need to fix the ignition barrel. I want to change the two sensors that the internal trans harness plugs into on the valve body. I need to check on part numbers for that. Other than that the only thing I did was clean up the thread in one of the rear hubs. I had slightly damaged 1 Bolt thread when putting it back on the ground last year. I got the correct app and just cleaned it up as it was just the very first thread engagement I had damaged. I damn well want to get this car back on the road and put a few 1000 miles on it this year.

AAZCD (Forum Supporter)
AAZCD (Forum Supporter) Dork
3/15/21 9:35 p.m.

No start... Turn the key and nothing happens? I had an issue with a Tiptronic Boxster where it wasn't quite all the way in Park as far as the switch thought. That car had been sitting for a long time and it may have just been a spec of corrosion in the wrong spot. I may have mentioned it early in this thread, but moving the shifter back and forth a few times and trying to crank in (N) and (P) finally got it working. It happened again once or twice, then never again. No repair was required after that.

Our Preferred Partners