oilhammer
Certified Volkswagen Nut & Vendor
Given the doom and gloom of the future of diesels, I've decided to not only horde any that I can, I've decided to convert one of my several gasoline powered Volkswagens to diesel.
The subject is my 2004 Passat wagon, which has the AWM 1.8t engine, automatic transmission, and 4mo AWD system (Torsen).
I've obtained a crashed 2005 BHW sedan, and I am looking for some pointers on what all I will need from this car before I scrap it. I know some here have done this sort of thing. The main difference I see as being potentially problematic going forward is the 4mo part, but more on that later.
I have already gotten:
the complete running engine, engine harness all the way to the ECU
the ECU
the fuel lines running across the firewall down to the rear of the car
sound deadeners on firewall
starter
brake booster tube and firewall grommets (different from the AWM)
cluster
trans controller
air cleaner and related plumbing
Now, I know the AWM's transmission (which is working fine BTW at 215k miles) is geared lower, but is otherwise the same basic ZF 5HP unit. For the time being, I'd like to just leave it alone. Hopefully I can swap in the TCM from the BHW which should make the shift points behave better because as it is now if you stab this gasser on the highway it will happily jump down a couple gears and let that AWM sing all the way up past 6k RPM, and pulls pretty good past 4k RPMs, right around where the BHW lays down and dies. So I NEED the shift points to be diesel-friendly, especially if the over all gearing has the engine spinning 600 RPMs faster at 80. I've thought about trying to swap the rear Torsen section of the 4mo trans over to the diesel trans, but then I'd also I'm sure have to change the rear differential, and if I am going to go through all that nonsense, I'd just try and source a manual gearbox. So for now I'd like to make the existing automatic work.
The lift pump is another concern. Since the fuel tank is different, the pump/sending unit arrangement is different, and there were no 4mo diesels sold here. Will the AWM's in tank fuel pump work to pump diesel to make the tandem pump work? If so, how will it be controlled? I have not yet investigated the control circuit for gas vs. diesel in tank pumps. I have also not yet looked into the ECU box on the AWM to see if all the same plugs exist on the car as on the BHW's harness. There are several color coded plugs. Luckily the trans harness is completely separate, as is the rest of the harness for the front of the car. So the engine stuff is TOTALLY independent of anything else, hoping most of this will be plug 'n play.
Going to have to blitz the immo and VIN from the ECU, not sure what I will have to do with the cluster. I'd like to roll the odometer forward though, as the donor car only has 98k miles. I will likely need to recode the ABS controller too, but that shouldn't be an issue.
The donor car had a HARD crash on the left front, as such it bent the power steering pulley which is different as well as the charge air cross tube, which is also different. So I still need to find those two items.
I just want to make sure there is nothing else I need from the donor car before I take it to the scrapper, then some pointers on the actual swap.
The subject is my 2004 Passat wagon, which has the AWM 1.8t engine, automatic transmission, and 4mo AWD system (Torsen).
I've obtained a crashed 2005 BHW sedan, and I am looking for some pointers on what all I will need from this car before I scrap it. I know some here have done this sort of thing. The main difference I see as being potentially problematic going forward is the 4mo part, but more on that later.
I have already gotten:
the complete running engine, engine harness all the way to the ECU
the ECU
the fuel lines running across the firewall down to the rear of the car
sound deadeners on firewall
starter
brake booster tube and firewall grommets (different from the AWM)
cluster
trans controller
air cleaner and related plumbing
Now, I know the AWM's transmission (which is working fine BTW at 215k miles) is geared lower, but is otherwise the same basic ZF 5HP unit. For the time being, I'd like to just leave it alone. Hopefully I can swap in the TCM from the BHW which should make the shift points behave better because as it is now if you stab this gasser on the highway it will happily jump down a couple gears and let that AWM sing all the way up past 6k RPM, and pulls pretty good past 4k RPMs, right around where the BHW lays down and dies. So I NEED the shift points to be diesel-friendly, especially if the over all gearing has the engine spinning 600 RPMs faster at 80. I've thought about trying to swap the rear Torsen section of the 4mo trans over to the diesel trans, but then I'd also I'm sure have to change the rear differential, and if I am going to go through all that nonsense, I'd just try and source a manual gearbox. So for now I'd like to make the existing automatic work.
The lift pump is another concern. Since the fuel tank is different, the pump/sending unit arrangement is different, and there were no 4mo diesels sold here. Will the AWM's in tank fuel pump work to pump diesel to make the tandem pump work? If so, how will it be controlled? I have not yet investigated the control circuit for gas vs. diesel in tank pumps. I have also not yet looked into the ECU box on the AWM to see if all the same plugs exist on the car as on the BHW's harness. There are several color coded plugs. Luckily the trans harness is completely separate, as is the rest of the harness for the front of the car. So the engine stuff is TOTALLY independent of anything else, hoping most of this will be plug 'n play.
Going to have to blitz the immo and VIN from the ECU, not sure what I will have to do with the cluster. I'd like to roll the odometer forward though, as the donor car only has 98k miles. I will likely need to recode the ABS controller too, but that shouldn't be an issue.
The donor car had a HARD crash on the left front, as such it bent the power steering pulley which is different as well as the charge air cross tube, which is also different. So I still need to find those two items.
I just want to make sure there is nothing else I need from the donor car before I take it to the scrapper, then some pointers on the actual swap.