Our T3 had 1.6TD JX 51kw engine but it was leaking oil and coolant etc. The plan was to take the engine out and rebuild it but then I realised that the more reasonable thing to do was to swap the engine to 1.9TD AAZ 55kw. They are both of the same basic family, so you can swap over all the T3 diesel’s mounting and plumbing bits to the AAZ and it is more or less just a direct bolt in deal, and you gain 10hp. There are some bits and pieces you have to take from your old engine.

Information below is not all written by me.

You can also see more about our engine swap – Click here

  1. Strip AAZ to bare engine, head and block, good time to replace cambelt and tensioner and check crank pulley and crank for wear. We did a full rebuild for cylinder head and the engine block.
  2. Fit JX sump and oil pick up pipe without windage tray. Don´t use the windage tray. It increases the width of the gasket as it were, then when you try to get the bottom bolts from bellhousing to sump they won-t line up.
  3. Use AAZ injection pump, modify throttle linkage.
  4. Use any T3 diesel throttle cable.
  5. Use JX exhaust manifold and JX exhaust.
  6. Use AAZ turbo, change attitude to suit JX exhaust manifold.
  7. Manufacture oil feed pipe for turbo. 
  8. Use T3 diesel clutch.
  9. Fit new spigot shaft bearing to crank.
  10. Fit block bung to back of cylinder block.
  11. Fit oil return line from turbo to sump.
  12. Use JX airbox and piping to turbo, relocate airbox to behind left hand light.
  13. Use JX water housings for cylinder head.
  14. Use AAZ waterpump to head rubber hose as the JX one isn-t long enough, block the spare end.
  15. Use AAZ inlet manifold, JX and AAZ ports are different shapes.
  16. Use which ever alternator/belt set up suits you, they are interchangeable.
  17. Use JX dipstick
  18. Small hole in engine lid, you need about 15mm increase in height on top of the injection pump. The position of the hole you need to make varies from model to model, early, late etc. Use these measures as guidelines to get you in the right area. But check everything before you cut the hole!! 

Useful information:

User manual and torque specs for 1.9L Turbo Diesel 1997-1998 Engine ALH, AAZ, AHH, AHU, 1Z  – Click here

Notes: Using the original AAZ exhaust manifold and turbo in it-s AAZ orientation results in oil not being able to drain from the turbo, engine will run on it-s own oil and self destruct.

Once done, fit new oil filter, fill engine up with 4.5l of oil and run, once run then remark dipstick to new level.

215mm clutch will be fine for standard AAZ in a VW T3, if you start tuning, then it won-t be strong enough and you will have to find an alternative method. The clutch from any of the T3 Disels will do, they are the same.
Don-t use the windage tray. It increases the width of the gasket as it were, then when you try to get the bottom bolts from bellhousing to sump they won-t line up.
Going the conversion with the info above will result in haveing 2 non genuine parts, the oil feed which some people just bend a JX one into place and the oil return line from the turbo JX one is too short.

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