Hello Peter, Your right about a leak off test on this engine is not easy.
The leak off pipes are bolted to the injectors, we have attachment’s that screw to the injectors and you can push the leak off pipes to them, you can see them here http://www.youtube.com/watch?v=mY4xCOW-LoE&feature=channel
This means running the car with the rocker cover off, you could make a cover for the timing chain to limit oil spray but it will be a messy test, it may make sense to remove the injectors and have them tested. Let me get the information on P1238 and go from there, have a good weekend, Martin.
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