Here at NW TEAM Yota we work on both "interference" and "non-interference engines.

What does this mean?

Interference engines are 4-stroke internal combustion engines. The design of an engines piston and valve paths determine whether it is an “interference” engine or a “non-interference” engine.

If the lowest point at which an engines valves decent is lower than the highest point the engines pistons rise, then the engine would be consider to be an interference engine. While operating under proper conditions the timing of the pistons and valves is such that they are prevented from colliding. If, for any reason, the timing of an interference engine is not correct, then one or more valves may make contact, which will result in extensive engine damage and therefore costly repairs. Toyota 20R, 22R, 22RE, 22RET, 2RZ-RE, 3RZ-FE engines are all chain driven interference engines. The 5VZ-FE and the 3VZE is a belt driven non-interference engine. Therefore the valves can not come in contact with the pistons if the timing is not correct.