Driving a 2016 E-450 withV-10 Triton engine. Have around 13000 miles on it. Have been noticing a rattling/almost knocking sound when traveling at around 60 mph. Doesn?t loose power and goes away at around 65 mph. Sometimes happens at around 30 mph, but not all the time. Told certified ford service tech about it and he said it?s normal in the V-10 Triton. I hav e not found many other comments about it. Anyone else experience something similar.