Hey guys, maybe you can help me out.
I'm having an issue with my 2013 BMW F30 328i. Basically, its making a very noticable rattle/clattering on rev-down.
I've made a full scan and came up with no codes. The rattle only ocurrs on "violent" rev-downs, If I let off the gas gently it doesn't happen.
I've inspected the timing chain from the oil cap, when cold there is some give to the chain, but the guides themeselves don't move at all (Maybe 1/2mm), so I don't think its a timing chain issue. Moreover there is no "whining" sound, just a rattle.
I've made a couple of clips, maybe someone can figure out what it is? In one of them I left the phone below the car, you can clearly hear the rattle, its coming from under the engine, maybe the flex pipe? I've had an A6 with flex pipe rattle, but it sounded much worse and only at a certain RPM, this rattles comes off whenever I lift my foot of the gas rapidly.
Another theory is that the wastegate might be rattling, specially since this ocurrs only rev downs.
What do you guys think? Anyone had this?
Cheers!