I changed the oil in my 2009 Traverse LS (156,000 mi) on Thursday. I replaced Castrol GTX High Mileage Synthetic Blend and a Fram TG10060 oil filter with direct replacements(same brands). Oil has been changed every 3-5000 miles throughout the vehicle's history. Today I noticed a knocking/clanking sound at around 2000rpm and a huge reduction in power(couldn't climb up my driveway). It seemed to idle higher than normal(usually idles at 500rpm, but was idling around 1200rpm) and a lot rougher than normal(rpms were bouncing up and down). Checked the oil level and it was good and the oil looked pretty clean(only 60 miles on the oil). Continues the rough idle in neutral and park as well. Any ideas on what might be causing it?