Rattle on hard accelation 1.6 cc 2004

[Magnum]

I have a rattle on hard acceleration in my Megane cc 2004 it does not do it on idle or normal driving I have no rattle on startup so I don't think it is the dephaser pully I have taken out the dephaser solenoid and cleaned it checked its working also change the oil and filter and also an engine flush to also on my 1.5 DCI has a wet patch in the back passenger side floor also in the front floor lift up cupboard any help on this problem is much appreciated