Does anyone know of an A4 converstion that has actually been done?
- Thread starter Gregp1962
- Start date
What I THINK I know about this conversion
I wish I did know of someone that has done one. I have been thinking about doing a 99 Passat and the A4 is the same. I can tell you it’s not an easy conversion. First the earlier TDI engine 98 or older seems more suited because the oil pan will fit from the early 1.8T from the Passat[99] or Audi A4. Also the intake is pointed toward the firewall instead of pointing front like the 99.5 ALH. The ALH will need a different pan from a later Audi A4 that has a front mounted oil pump and has the water pump turned by the T belt. The left motor mount might work off of the 1.8T with some mods but the right will have to be made up. The TDI engine has the turbo and exhaust manifold mounted much closer to the block than the 1.8T. The Passat and Audi A4 have a mechanical fan that mounts to the left front side area on the block. .This is where the injection pump is on the TDI . I am just going to keep all the accessories mounted like they would mount on a TDI in a Jetta and mount a electric fan on the radiator. The AC compressor will move from right to left but this is doable with making up some new lines. The Passat or Audi A4 1.8T flywheel is a direct bolt up and so is the bell housing. I am not sure there is enough room for the starter yet but it will close to the turbo. I have an early 99.5 wiring harness and ECU so it is pre imobilizer. The way to tell is a EB following the ECU part # and if the switchblade key has the stamped in W crossed out. Still other issues are the drive by wire pedal and the gearing is to short for good mileage. My Passat is about 2500rpm @ 60mph and a Jetta TDI is about 2000rpm @ 60mph. There are many more issues also like routing the intercooler hoses and fuel lines but I think it can be done. Does it make sense????? My Passant gets about 28 city and 34 highway so why bother! If I find a Audi A4 Avant with a bad motor then I will take a stab at it.
I wish I did know of someone that has done one. I have been thinking about doing a 99 Passat and the A4 is the same. I can tell you it’s not an easy conversion. First the earlier TDI engine 98 or older seems more suited because the oil pan will fit from the early 1.8T from the Passat[99] or Audi A4. Also the intake is pointed toward the firewall instead of pointing front like the 99.5 ALH. The ALH will need a different pan from a later Audi A4 that has a front mounted oil pump and has the water pump turned by the T belt. The left motor mount might work off of the 1.8T with some mods but the right will have to be made up. The TDI engine has the turbo and exhaust manifold mounted much closer to the block than the 1.8T. The Passat and Audi A4 have a mechanical fan that mounts to the left front side area on the block. .This is where the injection pump is on the TDI . I am just going to keep all the accessories mounted like they would mount on a TDI in a Jetta and mount a electric fan on the radiator. The AC compressor will move from right to left but this is doable with making up some new lines. The Passat or Audi A4 1.8T flywheel is a direct bolt up and so is the bell housing. I am not sure there is enough room for the starter yet but it will close to the turbo. I have an early 99.5 wiring harness and ECU so it is pre imobilizer. The way to tell is a EB following the ECU part # and if the switchblade key has the stamped in W crossed out. Still other issues are the drive by wire pedal and the gearing is to short for good mileage. My Passat is about 2500rpm @ 60mph and a Jetta TDI is about 2000rpm @ 60mph. There are many more issues also like routing the intercooler hoses and fuel lines but I think it can be done. Does it make sense????? My Passant gets about 28 city and 34 highway so why bother! If I find a Audi A4 Avant with a bad motor then I will take a stab at it.
adamss24
Veteran Member
Dont do it mate, it just doesnt make sense...There is so much fabricating and adapting and it wont look OEM. The engine harneses are different so the clocks,drive by wire pedals, fuel lines, exhaust mounts, gearbox, front panel, exhaust, vacuum lines and the list goes on... You will be better off finding a wrecked one of similar age and swap the parts and even then its a pain in the back- broken trims/clips and left over nuts and bolts. Best even save the money and buy one done by the factory. Good luck anyway...
dbywaters
Active member
There is a way,
Contact the folks at http://ultim8vwparts.com and they will set you up with all the parts needed. I hope to start the conversion of a 99 Passat to a TDI around November. My parts should ship soon. I am looking forward to starting.
Doug
Contact the folks at http://ultim8vwparts.com and they will set you up with all the parts needed. I hope to start the conversion of a 99 Passat to a TDI around November. My parts should ship soon. I am looking forward to starting.Doug
I can now confirm the 2001 Audi 1.8T pan will fit the ALH block. One concern was the two outer rear mounting bolts are 10 mm [instead of 7mm] because they use the rear of the pan as support for the bell housing. The ALH block is already taped for the 10 mm and they screw right in. You must have the right year Audi pan because there are three different ones that I know of. Hope this helps!!!!!!!!!!!!!!!!!!!!!!!!!
Last edited: