A3 to A3 swap

[Lug_Nut]

Spent about 20 minutes yesterday draining the gasoline from the fuel tank.
An hour and a half tonight disconnecting the drive axles from the transmission, disconnecting the three shifter linkages, and disconnecting the two pendulum mounts. I also pulled (actually sawz-all-ed) the cat converter out.
Did I mention that the Cabrio is a 1995? Did you know that cat converters <edit: for diesels> weren't required until 1996?
Depending on when the weather co-operates I'll undo the other three motor mounts and then I'm ready to pull the 2.sl0.
Cost: $3503
Time: 23 hours

 

[shortysclimbin]

Yes, but cats are required for any car that the oem provider equiped them on....

Looks like things are going well. May I suggest doing your tdi motor repairs now while its on the stand? A timing belt change is a quick job. so isn't the oil seals, clutch and CCV vent tube.

 

[k_harley]

As long as they dont peek under the car during inspection, (place I go doesnt) then you can get away without the cat.

Looks good so far! Looks like you will have the next week of bad weather to work on it and not miss sunshine.....but it had better be done by then!

As for those rusty fenders, that happens becuase the debris from the windsheild gets clogged at the bottom and has no where to go. I call it the VW compost pile. You will open the fender liner and find stratified layers of organic matter, with sand on the bottom, then soil, then leaves. Once I even found a plant growing out of one that had been parked for a long time.

Here's a secret, you can use the golf / jetta fenders by just cutting off the bottoms at the body line and add one tab for mounting inside. Far as I know you can only get new cabrio fenders from the dealer to the tune of $120 a piece.

 

[Lug_Nut]

The transmission is still attached to the AHU. The clutch is relatively recent and showed no signs of any slip or chatter while I abused it on my Jetta test drive. I'm leaving it alone.
The CCV tube is still free of cracking / oil dribbling. It isn't that difficult to access in the engine bay anyway.
The timing belt and rollers I might do while the engine it out. I do need to pull the belt cover to see if the Cabrio right side rail motor mount bosses are in the AHU block / head as they are for the ABA. If the mount can be installed on the AHU engine I'll do the belt now. If the mount isn't compatible I'll leave it off and then just do the belt later. It really isn't a problem on the 1Z /AHU with the engine in the car. Having the car in gear, wheels on the road really helps in breaking loose the crank pulley bolts.

I wasn't aware until I really compared that the Cabrio rocker boxes run the full length and the fender stops above the rocker box. So much for $35 chinesium replacement fenders that bolt on... Yeah, I had considered Golf/Jetta fenders, notching the lower end and bending that lower end upward to form the tab, but I'll likely leave that to the body shop to figure out when I have it painted.

Another 2 hours after work tonight. The 2.0 / 020 combination is longer than with the 02A. I couldn't lift it straight up to remove it. I removed the front motor mount cross member to pull it out to the front instead.
That's the ABA 2.0 on the ground by the rear of the car. The AHU is inside the garage.

I've started the wiring extraction. There are three bundles through the firewall, not just one as the Jetta donor had. One is for the ABS, the second main one is the similar engine harness, but the third one, much smaller in number of conductors, I haven't looked into yet.

Still have to remove the underside heat shield and the shift linkage and finish extricating the engine bay wiring.
Then a clean-up and start re-assembling with AHU bits.

Cost is still at $3503
Labor time is up to 25 hours

 

[k_harley]

Its ABS / Engine / Cooling harnesses

For some reason they seperated the engine and cooling harness like on a passat. Not sure if they did this with all years of cabrio's.

 

[Lug_Nut]

Thanks for that tid-bit. I'll still probably have (want to) pull the two harnesses and install the single TDI harness and transfer a firewall plug.
I also found that the AHU intermediate shaft pulley is right where the Cabrio chassis' right side pendulum mount should go. Looks like that "engine as damper mass" isn't going to work with the AHU in the A3 Cabby. I'll use the three usual mounts and will try with the transmission pendulum mount. If that causes weirdness then that pendulum will also be pulled.
I also found that the cam belt tensioner was not functioning. The notches weren't lined up, there was next to no tension on the belt, and the tensioner is siezed so it can't be adjusted anyway.
Noted, and added to the lengthening list of to-do's.
<edit: installed a used tensioner, from an early, under 60k mile, B4 belt change, that I had kept as a 'spare'.>

 

[Lug_Nut]

Engine wiring harness is out. (The three harnesses are for Engine, ABS, Cruise Control Module, redundant with the TDI ECU). I'll pull the superfluous CCM harness later. The shifter boxes have been swapped. The exhaust heat shield reinstalled. The clutch cable is out. The clutch master is in with the transferred retainer clip in the pedal (not on the '95).

There is a back-up reinforcement plate for the clutch master that attaches inside the firewall. The brake pedal support interfered so I transferred the support from the Jetta. I could have cut and trimmed, but I have the parts car anyway.....

I also am not pleased to discover that the mounting bracket for the throttle pot is not installed in the cabby. The pedal attaches just fine, but there is nothing to which the pot can be mounted. I have to transfer the pot bracket to get the drive-by-wire signal.

Cost is unchanged at $3503
two more hours Friday evening and 3 1/2 this morning for a total of 30 1/2.

 

[compu_85]

Jon, are you keeping the ABS? Is the ABS harness integrated with other harnesses on that car? I'm helping a buddy do this swap into what was a GLX automatic, and I"m not looking forward to removing the whole abs / auto trans harness to delete the auto stuff.

-Jason

 

[Lug_Nut]

Mine is a manual. The ABS harness is a separate stand-alone entity unto itself. I don't know if the ABS and automatic transmission controller wiring is shared/conjoined. The TCM is under the rear seat, the ABS controller in under the hood. I'd expect them to have totally separate harnesses, but I don't know that absolutely.

Compu: Next time a coolant hose splits: Electrical tape around the hose, cable ties or shoelaces to hold the tape, leave the radiator cap/ overflow cap loose, drive on!

 

[Lug_Nut]

I had one last use-it-or-lose-it vacation day left for this fiscal year ending on Friday. Work was delayed pending repairs to the equipment at the office, so I took the day off.
Nice weather actually, total overcast, mid-upper 60's, slight breeze, a good day for outdoors work.
The wiring harness is in and installed in the engine bay, the fuse block is still not touched, but .... The engine and transmission are in and mounted, A/C lines re-installed, radiator installed, axles are bolted up, throttle pot is installed, pedals are installed, clutch slave is installed, shift cables are attached.

Still to do: fuse block connections, fluids, fuel filter, mount the N75, vacuum hoses, intercooler and mounting,....hmmm... I'm probably forgetting something....

Cost is up to $3522 with the 13 mm flex head box ratchet (for the throttle pot bracket) which saved pulling the brake master off for access.
Labor is up to 38 1/2 hours

 

[Lug_Nut]

Another two hours tonight.
Some information: The studs on the right strut tower are shorter. The fuel filter mount, and EGR valve mount, AND the plastic spacer under them won't all fit. I left the plastic spacer out. The only issue I see is that the tower's curve would allow the bottom of the filter to contact the tower if the filter were pushed down as far as usual. I left it raised up about 1/2 inch for clearance at the base to tower and the top to hood. Fuel tank lines are connected, engine lines are connected.
Intercooler and support are in. One rigid pipe left to connect.
Lock carrier and bumper are bolted on. Grille has a new center emblem from the Jetta snapped in. Hood latch and cable is in and adjusted.
The unleaded fuel nozzle restrictor in the filler neck has been cut apart and removed in pieces.

Getting nearer! Fluids, fuse block connections and exhaust are about all that is left.

 

[phazersonstun]

Dude! You are just tearing through this swap! Good job! Got anymore pictures?

 

[Lug_Nut]

I'm working too fast to stop for pictures!
I'm trying to get it running and able to move under its own power for this weekend (Happy 50th birthday present to me), then to finish up before the 4th (Happy 232nd, USA).

The two additional, Cabrio only, pendulum mounts for the 2.0 / 020 combination can't be used with the AHU / 02A combination. The belt end of the block might have mounting locations for the right side mount, but the intermediate shaft pulley covers them. The bosses at the tail of the 02A are not lined up with the welded-on frame attaching point so that left side mount can't be used either. Oh well, I'll just have to live with only three mounts as all the other A3 do.....

The wiring connections to the fuse / relay block have begun. Some items I need to decide how to do include powering the '95 recipient 2.0's in-tank fuel pump (normally full time from the relay in position 12) when the '97 donor TDI ECU doesn't power relay 12 socket (1996 1Z glow plug relay 103 location), but instead uses a remote socket (1997 1Z and AHU glow plug relay 180 location). That and adding a fuel shunt so the pump doesn't over pressurize the TDI's usual 'negative' pressure filter and fuel supply system. The 2.0 in-tank pump's 3 bar capability needs to be knocked down to about 1/10th that for my comfort. If I can do that without buying a regulator, I'll be happy.

I now have a loaner Bentley with 97 TDI wiring schematics and will also have my early edition Bentley open to the 95 Cabrio wiring to join them in holy matrimony. Do you, '95 OBD, take you, '97 OBD II,.....

I'll take some more pictures tonight or if it's still raining, then tomorrow morning.

 

[shortysclimbin]

95 to 97 I do
97 to 95 I do

"you may now connect the bride"

Granted I am sure they already got there premarital crap in order.. you know a little solder here.. wire there... ow tape this zip wrap that...

 

[Lug_Nut]

Here's the fuel filter spacer that is too thick to be used. Notice how little of the mounting studs project through the nuts with just the filter bracket and EGR valve bracket.

Another little surprise: The 95 and 97 have different plug and socket arrangements. Note that a two pin plug has to mate into a three pin socket. Fortunately only two of the three are occupied and by trimming away a bit of a 'keying' projection on the plug I was able to make the connection. The offset of the two plug in the three socket means that one locking tab is useless, but I believe it will be fine.
Depending how I feel about it tomorrow when I resume, I might extract the terminals from one or the other and install in a fully mating receiver.
<edit: This was a bit confusing. The Bentley schematic show this three pin (one empty) and two pin connectors as ends of one wire segment used to send power to the directional indicators in the instrument cluster. The Cabrio had a 3-2 plug configuration, the Jetta had a 2-2 configuration? I had enough length to connect the Jetta donated cluster into the Cabrio body harness, thus the 2 plug into the 3 socket.
I later ran into problems with a ground fault (jump ahead to post #52 if you wish, then come back here) in the right front directional and in the process of elimination I re-installed the wiring that made the adaptation from the Cabrio's 2 pins in a 3 location socket to the jetta's 2 pins in a 2 position socket. Didn't help the short circuit, but I left the connections alone.>

Anyway, this is how the engine bay looks tonight: Full of AHU!

 

[Sprocket]

Very impressive!

 

[phazersonstun]

THAT IS SWEET! That is gonna be a fun cabriolet! What airbox did you use?

 

[compu_85]

Looks like the stock one from the AHU donor car.

-Jason

 

[Growler]

Good job! Bringing it to Fest?

I wanna see this thing. Happy Birthday!

 

[Lug_Nut]

I used the whole AHU donor air box. I could have used the base from the ABA, but the top with MAF are different.
My intent is to have it well sorted before I bring it to the 'fest.
I found out while struggling to make the glow plug relay and fuse connections that the 1997, "V" vin, donor actually uses the 1998, "W" vin glow plug wiring. Now I have to go back and recheck what else is different.

 

[Lug_Nut]

The blending of the different harnesses didn't go so well, apparently.
I have a serious amperage draw with everything turned off. Audible sparks when the negative cable is put to the battery post.
Pulling all the relays and all the fuses reduced the current, but there is still voltage flow somewhere.
Time to take time, separate everything and to proceed through the circuits one by one.....
sigh.....

40.5, plus 6 more (fruitless) hours today, bring the time investment to 46.5
Dollar investment is holding steady.

 

[Lug_Nut]

You sure? I thought all Ventos were 4 doors.

One other difference you will encounter will be the airbag wiring, the 1998 car will have a different connector for the airbag warning light (which is in the cluster of the TDI not on the little filler piece like the 95).

Personally I would remove the airbag system from the 1998 car and install it in the 1995 one, as the 1998 has de-powered airbags.

-J

The 1997 air bag system has the belt pre-tensioner cylinders which the 1995 doesn't have. The controller for the 95 is a 30 pin unit, the 97 uses a 50 pin unit. Rather then deal with those differences I'll be leaving the Cabrio's system intact.

Would someone be so kind as to obtain the A/C cut-out relay (#1 position) production code number? My AHU donor had the key-in, door-open chime module installed in that position. The 95 2.0 doesn't use a cut-out relay so it was vacant in the recipient. The #1 position relay in the 1998 A3 TDI relay block photo I posted in the glow plug sticky in the A3/B4 general maintenance is washed out and illegible.

 

[Lug_Nut]

After some hemming and hawing I decided to completely pull apart the wiring. I came to the conclusion that I'd rather not have that nagging knowledge that the wiring wasn't done neatly, or with semi-secure connections. I'm pulling pins and transferring connectors to eliminate that type of two pin plug into a three position socket 'cheat' that I showed above.
The clusters have been adapted, the cluster wiring has had the glow plug lamp wiring added. The rat's nest under the dash has been neatened and now at least looks manageable. I should have done that from the start.
I'll start (again) to make the connections. Another 6 hours shot, another $8 invested in wire wrap and cable ties.
52 hours
$3530

 

[tdidieselbobny]

Don't forget you can sell the used cat. converter if it's still good,then sell the A3 for scrap and get some $$$.... looks good-seems like all the conversions you do your wife ends up with.....

 

[compu_85]

Jon, if I were you I would install the ETR equipped seatbelts... they make a big difference. If the 95 has the tear out belts like my buddy's 94 does you'll really want them out of there. Look at where the belt anchors to the car. If there is a big rubber cover you can pull up and reveal a section of the belt that is sewn over on itself it has the tear out belts.

I'm looking at getting a 1993 TD Jetta, and will remove the tear out belt on the driver's side.

-J

 

[Lug_Nut]

I have concerns about the 2 door vs. 4 door belt length, mounting point differences between the German Cabrio rocker box vs. the Mexican Jetta rocker box, the Cabrio roll hoop mount vs. the Jetta B pillar mount, the lack of belt pre-tensioner igniters in the Cabrio harness, the lack of output signals from the Cabrio airbag module to trigger the belt pre-tensioners if the pre-tensioners and belts were able to be transferred from the four door Jetta.
Oh, and did I mention that the front passenger Jetta belt is already damaged from the accident that resulted in that car being branded "salvage"?
No, I won't be swapping belt and pre-tensioner items.


And I have yet to see a seat belt (or 50 ton capacity lift sling, or ratcheting tie down, or...) web end that hasn't been folded back and sewn onto itself to make the attaching loop.
There may well be strain evident threads woven into the belt that have lesser stretch properties and break well before the rest of the belt web stretch has reached break point, but these threads are intended to indicate that the main web has exceeded it's design safe limit and should be replaced, even if it looks fine.
Are these lesser stretch threads the "tear-out" that you mention?

 

[compu_85]

Yes, it's a section of the belt that is designed to fail right above the normal folded over attachment point.

What one looks like after it's been used up:

http://www.iihs.org/ratings/controls/image.ashx?rh=123&id=3

The belt tensioners do not connect to the airbag harness on cars without side airbags. They are simply set off by the shock of the crash.

-J

 

[Lug_Nut]

There are only two air bag igniters (N95, N131) connected to the 30 pin air bag module in the 1995 (and through 1999) Cabrio.

There are four igniters (N95, N131, plus N199 and N200) connected to the 50 pin air bag module in the 1997 Jetta. The 1997 Jetta also has two sensors (G179, G180) that are described as "crash sensor for side airbag, driver's side", and "....passenger's side".

 

[oilhammer]

Does that '97 have side airbags in the seats? That was a really rare option on the A3.

Come to think of it, I did not think it was even available as an option until 1998. What is the production date on that '97? 10th VIN digit?

 

[k_harley]

Those sensors are on the bottom of the door jamb. Pull back the plastic trim on the jetta on the floor next to the door, you will see a 18" long black plastic tube with what looks like a cable housing coming out of it. Thats your side crash sensor.

Why not just leave the 95 airbag stuff the way it is? I dont know if I misread something...should not be integrated with engine wiring.

Seat airbabs in a 98? Ive never heard of or seen one until MK4's or MK3.5 cabrio.