Knocking problem bmw e39 530d, under load, solved info in description, 

BMW e39 530dA 142kW 2002.
After many not necessary replacements the problem was the high pressure common rail pressure sensor connector, after I change the sensor it was a bit better, but when I took apart the connector and cleaned it, problem was solved. Hope it helps.
Be aware that sometime its not the sensor, but the cable or connector, this is very tricky problem.
IT IS THIS NUMBER 24
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