ok so toyota sent my dad the owner of this car a paper that said 8 years/unlimited miles we will fix the problem free for engine oil sludge problem. now the car smokes bad on start up and also loss of power and mileage, oil was changed usually at 3,000 miles but sometimes at a maximum of 4000. Toyota said we need documentation of oil changes and when my dad said he changed the oil himself they said that wasn't good enough because their isn't any proof he changed the oil. So we made an appointment at the dealership, and when we got there after our 1.5 hour drive they said that our car wasn't under that warranty then later we got in contact with some head guy somewhere and they said we could get a new engine if the sludge problem happened only if our car was under 100,000 miles. so we did nothing and drive it the way it is, with the check engine lite on. anyway its not a huge problem just an annoyance