|
I do not think it is a Rod knock, but perhaps you could let us know if you figure out what it was?
My 2013 M5 is doing the same thing. I went to a BMW shop and they (confirmed by other mechanics) follow BMW recommendation that the most likely cause is a leak in exhaust caused by manifold bolts in the V that back out. I had several backed out 10mm and they were replaced along with all of the gaskets there. They replaced breather hoses, heat shields,, oil lines and coolant lines related to the inter coolers.
They indicated when they shut down fuel and spark to #1 the noise stopped.
They had no other recommendations for me and failed to diagnose.
I took the car home, replaced all of the plugs, ignition coils and the injector in #1.
I changed the oil using Liquid Moly Hydraulic lifter fluid additive and ran for a few hundred miles.
I followed old videos recommendation to have car at temp and run past 3k RPM for 3-4 minutes.
The noise continues. At this point I'll either drive it until it breaks something, or take to a shop to replace lifter #1.
Did you ever get yours fixed?
|