Mk4 AFP VR6 swap into CE2 MK2
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I know I’m far from the first to do this swap, but when searching for info I came up with limited results.
I’m not going to go into detail on every step, just the big stuff that is different than an AAA mk3/Corrado/Passat VR6 swap. Mk4's are becoming affordable donors and are 10 years newer than most passats and corrados used for donors.
I picked up my donor for $2,000 with 55k.
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Here’s what I found;
Hardware.
The AFP bottom end is the same as the AAA found in mk3’s, passat’s and corrados. I used mk3 VR6 mounts, which bolted directly to the AFP block.
I used BFI green stage 2 mounts in a mk3 2.0 subframe for the rear engine and transmission mount. I used a MMP solid mount on a g60 front cross member for the front mount. Due to clearance issues with the hood and to help level out the engine, I cut ½” off the rear engine mount.
Stock mk3 mounts should work fine though.
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Downpipe.
The stock mk4 VR6 downpipe fits well. I used the single piece downpipe/cat style. Later styles are two pieces. I just had to cut a few inches off the post cat pipe to fit well with my TT 2.5” cat back exhaust.
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Heater core.
This isn’t necessary to replace, but I like the mk4 style hose clamps better. The mk4 heater core fits in the mk2 heater box.
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Tachometer.
Same as any other VR6 swap you can fool the mk2 cluster by doing the following;
http://forums.vwvortex.com/showthre...ing-a-VR6-tach-signal-work-with-a-Mk2-cluster!
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Gauges.
For oil pressure and coolant temp you can use mk2 sensors in the mk4 housings. The mk4, like the mk2, has two coolant sensors, one for the ECU and the other for the gauges. Replace the mk4 gauge sensor with a mk2 sensor and use the mk2 wiring.
I chose not to use the oil gauges in the cluster because I ran out of room on the oil filter housing when I added VDO sensors for oil temp and pressure for my Duo Style gauges.
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Transmission.
I used the mk4 02J transmission with mk3 mounts. I swapped the axle cups with mk4 02J TDI cups which are 100mm vs. the VR6 which are 108mm. This allowed me to use stock 100mm mk2 axles.
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For linkage I used the mk4 02J shift box. With a little trimming of the tunnel and notching the shift box, it bolted together nicely.
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Radiator/Condenser/Fans
I used all mk4 parts because I had them, but they are not necessary. You could use the normal corrado setup used in most VR swaps. I had to cut up the rad support and not use the lower rad support. I welded on supports on the sides that bolt to the condenser to hold it in place. These straps also 90 under the radiator and bolts to the front cross member. The whole setup is kinda like a mk4 rad support now.
The benefits are that the radiator and fans are larger than corrado and newer. The mk4 uses two electric fans. I used the mk4 fan control module and wired in an AC switch and an Aux fan switch. So now the fans turn on with the AC, by the temp switch, and/or by a manual switch.
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This required notching the front cross member for the lower hose to go through. I haven’t decided if this was a good idea or not.
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Speedometer.
The mk4 02J electronic speed sensors unscrews from the gear that goes into the transmission. A g60 speedometer cable screws right in and clips into the mk2 gauge cluster.
Throttle/pedals
I used the DBW mk4 setup. This has been done many times in the past and there is lots of info other there on it. I started with a g60 pedal cluster and cut off the throttle pedal.
G60 on left, mk4 on right
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The mk4 pedal unbolts from the bracket. I cut the bracket off the mk4 cluster and welded it to the mk2 cluster.
And done
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Brakes
I used mk3 2.0 knuckles, g60 rotors and calipers, dual drilled to 5x100 & 4x100. Rear disks.
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And the normal g60 non abs master cylinder/booster/clutch master setup
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Wiring.
I found the following here when looking for a mk4 VR6 ECU pin out.
This is for a 1.8t so some of the wiring and harnesses are different.
http://www.clubgti.com/showthread.p...-wiring-1-8T-gt-Mk2-harness-install-FAQ/page2
My donor mk4 was a 99.5, so some of the later wiring may differ as well.
These are the wires to splice into the mk2 CE2 wiring
T6-brown connector
pin 1 -black or black/purple 15 amp fused switched live 15 to ecu T121/3 (g1 pin 4)
pin 2 - purple/white ecu T121/65 to fuel pump relay ground (g1 pin 3)
pin 4 - red/green 20 amp fused constant positive 30 to ecu T121/62 (Y pin 4)
pin 5 - blue/yellow fused 10 amp from fuel pump relay (g1 pin 10)
T10 - 10 pin connector near battery
pin 5 - red/purple 10 amp fused switched live to injectors (183) ( Z/1)
pin 6 - yellow/black fused 10 amp from fuel pump relay (g1 pin 8)
pin 7 - brown ground (204) (197) (Ground to chassis or battery)
pin 9 - brown/white earth for senders (G1 pin 6)
T10G - Green connector
pin 4 - white/red ecu T121/39 to clutch pedal switch (Clutch pedal switch in car) (I didn’t do this as I used the mk2 starter wiring)
T10 Orange
pin 1 - grey/white to ecu T121/43 (229) ( diagnostics K diag port)
pin 6 - blue/white ecu T121/54 to speed signal in dash wiring (Hall speed sensor on clocks W pin 1)
No modifications needed on the Blue connector for the drive by wire pedal setup.
And here is a spreadsheet I made of the mk4 ECU pinout double check everything. The PDF can be down loaded here: Will host on dropbox and add link later
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And the mk4 Bentley can be downloaded here. Right click, save as only: http://dl.dropbox.com/u/4387578/Vol....Official.Factory.Repair.Manual.1999-2005.pdf
I ran all the wires by the heater lines and put the ECU in the rain tray. This allowed no modification of the mk4 harness from the ECU to the engine. I ran all the other wires through the rain tray, though the wiper harness hole and to the fuse box.
I’ll add more pics of that here later.
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And done.
![]()
Thanks to all those who answered my questions along the way :thumbup:
I know I’m far from the first to do this swap, but when searching for info I came up with limited results.
I’m not going to go into detail on every step, just the big stuff that is different than an AAA mk3/Corrado/Passat VR6 swap. Mk4's are becoming affordable donors and are 10 years newer than most passats and corrados used for donors.
I picked up my donor for $2,000 with 55k.
Here’s what I found;
Hardware.
The AFP bottom end is the same as the AAA found in mk3’s, passat’s and corrados. I used mk3 VR6 mounts, which bolted directly to the AFP block.
I used BFI green stage 2 mounts in a mk3 2.0 subframe for the rear engine and transmission mount. I used a MMP solid mount on a g60 front cross member for the front mount. Due to clearance issues with the hood and to help level out the engine, I cut ½” off the rear engine mount.
Stock mk3 mounts should work fine though.
Downpipe.
The stock mk4 VR6 downpipe fits well. I used the single piece downpipe/cat style. Later styles are two pieces. I just had to cut a few inches off the post cat pipe to fit well with my TT 2.5” cat back exhaust.
Heater core.
This isn’t necessary to replace, but I like the mk4 style hose clamps better. The mk4 heater core fits in the mk2 heater box.
Tachometer.
Same as any other VR6 swap you can fool the mk2 cluster by doing the following;
http://forums.vwvortex.com/showthre...ing-a-VR6-tach-signal-work-with-a-Mk2-cluster!
Gauges.
For oil pressure and coolant temp you can use mk2 sensors in the mk4 housings. The mk4, like the mk2, has two coolant sensors, one for the ECU and the other for the gauges. Replace the mk4 gauge sensor with a mk2 sensor and use the mk2 wiring.
I chose not to use the oil gauges in the cluster because I ran out of room on the oil filter housing when I added VDO sensors for oil temp and pressure for my Duo Style gauges.
Transmission.
I used the mk4 02J transmission with mk3 mounts. I swapped the axle cups with mk4 02J TDI cups which are 100mm vs. the VR6 which are 108mm. This allowed me to use stock 100mm mk2 axles.
For linkage I used the mk4 02J shift box. With a little trimming of the tunnel and notching the shift box, it bolted together nicely.
Radiator/Condenser/Fans
I used all mk4 parts because I had them, but they are not necessary. You could use the normal corrado setup used in most VR swaps. I had to cut up the rad support and not use the lower rad support. I welded on supports on the sides that bolt to the condenser to hold it in place. These straps also 90 under the radiator and bolts to the front cross member. The whole setup is kinda like a mk4 rad support now.
The benefits are that the radiator and fans are larger than corrado and newer. The mk4 uses two electric fans. I used the mk4 fan control module and wired in an AC switch and an Aux fan switch. So now the fans turn on with the AC, by the temp switch, and/or by a manual switch.
This required notching the front cross member for the lower hose to go through. I haven’t decided if this was a good idea or not.
Speedometer.
The mk4 02J electronic speed sensors unscrews from the gear that goes into the transmission. A g60 speedometer cable screws right in and clips into the mk2 gauge cluster.
Throttle/pedals
I used the DBW mk4 setup. This has been done many times in the past and there is lots of info other there on it. I started with a g60 pedal cluster and cut off the throttle pedal.
G60 on left, mk4 on right
The mk4 pedal unbolts from the bracket. I cut the bracket off the mk4 cluster and welded it to the mk2 cluster.
And done
Brakes
I used mk3 2.0 knuckles, g60 rotors and calipers, dual drilled to 5x100 & 4x100. Rear disks.
And the normal g60 non abs master cylinder/booster/clutch master setup
Wiring.
I found the following here when looking for a mk4 VR6 ECU pin out.
This is for a 1.8t so some of the wiring and harnesses are different.
http://www.clubgti.com/showthread.p...-wiring-1-8T-gt-Mk2-harness-install-FAQ/page2
My donor mk4 was a 99.5, so some of the later wiring may differ as well.
These are the wires to splice into the mk2 CE2 wiring
T6-brown connector
pin 1 -black or black/purple 15 amp fused switched live 15 to ecu T121/3 (g1 pin 4)
pin 2 - purple/white ecu T121/65 to fuel pump relay ground (g1 pin 3)
pin 4 - red/green 20 amp fused constant positive 30 to ecu T121/62 (Y pin 4)
pin 5 - blue/yellow fused 10 amp from fuel pump relay (g1 pin 10)
T10 - 10 pin connector near battery
pin 5 - red/purple 10 amp fused switched live to injectors (183) ( Z/1)
pin 6 - yellow/black fused 10 amp from fuel pump relay (g1 pin 8)
pin 7 - brown ground (204) (197) (Ground to chassis or battery)
pin 9 - brown/white earth for senders (G1 pin 6)
T10G - Green connector
pin 4 - white/red ecu T121/39 to clutch pedal switch (Clutch pedal switch in car) (I didn’t do this as I used the mk2 starter wiring)
T10 Orange
pin 1 - grey/white to ecu T121/43 (229) ( diagnostics K diag port)
pin 6 - blue/white ecu T121/54 to speed signal in dash wiring (Hall speed sensor on clocks W pin 1)
No modifications needed on the Blue connector for the drive by wire pedal setup.
And here is a spreadsheet I made of the mk4 ECU pinout double check everything. The PDF can be down loaded here: Will host on dropbox and add link later
And the mk4 Bentley can be downloaded here. Right click, save as only: http://dl.dropbox.com/u/4387578/Vol....Official.Factory.Repair.Manual.1999-2005.pdf
I ran all the wires by the heater lines and put the ECU in the rain tray. This allowed no modification of the mk4 harness from the ECU to the engine. I ran all the other wires through the rain tray, though the wiper harness hole and to the fuse box.
I’ll add more pics of that here later.
And done.
Thanks to all those who answered my questions along the way :thumbup:
