The only part on my engine (other than O2 sensors) that has failed in my 9 years of ownership -- the thermostat. Acura uses a rubber o-ring on the moving plate that can come dislodged and "mushroom", preventing proper operation of the thermostat, such as won't fully close or restricted flow. I replaced mine nearly 4 years ago with the same-temperature NAPA "generic" thermostat with excellent results.