After replacing two coils, 6 spark plugs and a injector cleaning service, my newly purchase with a 140K miles has a blown (leaking) head gasket. The coolant reservoir had to be topped off twice within a month, so I knew! Coolant was slowing leaking into cylinder 4 and 6 causing a misfire. This was discovered on the last day of my 90 day Powertrain, so the small dealer "said" he is covering the parts and labor for this expensive repair. After additional research, this problem was due to a faulty head gasket and Toyota corrected the problem with a new gasket. It appears that it only affected 2005 models!