Has anyone else had an engine failure in a 2011 Santa Fe? Mine - 86K miles, gradual increase in cold-start knocking, rough idle, low frequency rumble thought to be exhaust system, excessive downshifting skipping from 6th to 3rd (at 80mph), no change in mpg, etc. Dealer took one listen, gave me a brand new 2018 Santa Fe Sport rental and it's been two months waiting on a back-ordered short block engine. Problem - special coating on pistons flaked off of one causing cylinder wall scoring and abrasive debris in oil. Bought it as certified used w/16K miles and third-party extended warranty which is covering everything except any more than the first 11 days of rental. But at $25/day after that it's still costing me a small fortune.