Toyota 3MZ-FE

The 1MZ-FE bored out to 3.3, at 225 to 230 hp, in the Camry, Sienna, Highlander and the Lexus ES 330 and RX 330. Read its predecessor's page first — they share an architecture and most of a fault picture.

What Toyota fixed here was knock detection. The earlier MZ's knock sensors were a known weakness, and the 3MZ took a new flat-type sensor and electronic throttle control. A knock-sensor code on this engine is therefore worth taking at face value, where on the 1MZ it was often the sensor itself.

What it did not fix is the sludge, and that is the point worth carrying across. The warranty extension and the class action ended with the 2002 cars, and this engine is later — so an owner reads that the problem was "taken care of" and finds no coverage and the same gelling. Treat the oil history of a 3MZ exactly as you would a 1MZ's; nothing about the larger engine drains better.