Getting started with a TDI® Swap Project

The TDI®, which stands for Turbocharged Direct Injection, is a diesel engine produced by Volkswagen®. Diesel Conversion Specialists® currently offers products for the conversion friendly 1.9L TDI engines built from roughly 1996-2003. These engines are also known as AHU and ALH. The AHU could be found in a VW Jetta® from 1996-1999. The ALH took its place from 1999.5-2003.

The AHU and ALH TDI’s seem to be the most conversion friendly and economical to swap. The 2003 and newer versions are more heavily integrated with wiring and ECM algorithms, which may deter some builders. The deterrent is often the reliance on electrically operated components along with the time and money it takes to get them operational. Our team has been pleased with the ALH and AHU conversions, even though are products may fit other eras of the engine.

When it comes to your vehicle selection, we recommend to keep it light. The 1.9L TDI is a torque producing power plant for its size, but the 2003 VW Jetta TDI curb weight is around 3,000 lbs. Keeping weight in mind, 3,000 lbs is a good weight to base your vehicle decisions around. Going with too heavy of a vehicle may set you up for performance disappointment.

The 1.9L TDI engines are most often found in front-wheel drives. The engine is designed to sit transversely in the engine bay, which can create space issues with four-wheel drive and steering components when transplanting the engine into another vehicle. It’s a tall engine when installed upright. Often a suspension or lift kit will be used in smaller trucks like the Tacoma® or Ranger®. There is a lot of fab work to be done once the engine is set in place. From an air intake cooling system to getting all the engine coolant lines running in the right direction, be prepared for some late-night fabrication time if you’re on a deadline.

We do offer parts for a TDI conversion. Click here to see a list of options available from Diesel Conversion Specialists®.