We offer comprehensive 1.9PD TDI conversion systems for YJ, TJ/LJ, and XJ* (manual trans)- starting at     $5,495 USD.

Our packages are compatible with all 1.9 (PD) TDI engines from Volkswagens late 2003 through 2006 production. TDI’s fit with our upgraded camshaft and VNT based turbo deliver a healthy150hp and 260ftlbs of TQ.


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Our owners report 25-32mpg across a wide variety of tire sizes and gearing options. It is the immediate TQ delivery however that our owners claim out shines the doubling in fuel mileage.

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Our goal is to break down the TDI conversion to the simplest level so only a VW long block assembly is being installed. By retaining as much “Jeep” as possible under the hood, we simplify field service and support.

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Currently, The Cotybuilt conversions systems support only manual gearboxes. We have designed a cast aluminum adapter plate with CNC crank adapters that reposition the oem Jeep* Flywheel allowing builders to retain Jeep specific clutch kits.

When building the YJ and TJ, the gearbox’s original location remains unchanged allowing full compatibility with existing lift kits and Jeep performance parts. XJ requires both a lift kit and driveshaft length adjustments.

Gear boxes supported AX5*, AX15, NV3550, NSG370

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Due to the low target speeds for most Jeeps, oe Volkswagen air to air inter cooling was not the optimal choice. Cotybuilt has packaged a liquid cooled after cooler and preformed all the boost plumbing in black silicon pipes to facilitate a neat and tidy under hood installation. The shorten boost track combined with the stable intake temp range allow the engine management software to be optimized for immediate throttle response on and off the trails.

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Over the past five years, the number of variations documented between platform production runs and model years has been staggering. The Cotybuilt team has developed an installers group. This addresses the following

Gas pedal installation bracket – radiator spacer and after cooler mount.

Relay bracket, fuel filter bracket – fuel pump housing and a list of others that are platform specific.

CAD designed, CNC machined and tig welded, this comprehensive system takes the engineering fears out of the mix and results in an OEM look and feel under your hood.
*AX5 water jet adapter and requires new flywheel
*XJ/MJ requires min 3" lift and modified driveshaft lengths.
*TJ/XJ instruments 1997-2002-split application 03-06