by PintoAutoMk4 » Sat Aug 13, 2022 10:09 am
I've owned a 1994 Mk4 Auto 2.0 EFI petrol SWB for about 10 years. Lovely to drive, overdrive on 4th gear so a good motorway cruiser, but a bit of a plodder on hills. Fuel consumption is not great at 25mpg, but as a campervan annual mileage is low, so not really a problem.
The only problem I've had with the A4LD autobox is the vacuum modulator failed. This is mounted on the outside of the gearbox and is connected to the inlet manifold by a pipe. If the diaphragm in the modulator fails, the transmission is reluctant to change up to a higher gear and transmission fluid gets sucked into the engine and burnt, causing falling fluid level and exhaust smoke. To check it, with the engine stopped, pull the pipe off the modulator. If there's transmission fluid in the pipe, the modulator has failed. As it's mounted on the outside of the gearbox, it's an easy fix if you catch it before the fluid level gets low enough to cause any damage.
I met another forum member who had the transmission fail because the steel pipes running to the fluid cooler in the radiator rusted through, causing massive fluid loss, so it's worth inspecting the pipes regularly.