One problem related to loud engine noise has been reported for the 2006 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Toyota Sienna based on all problems reported for the 2006 Sienna.
Today I noticed a smell but thought it was from the road construction. Later I noticed some liquid on the ground under my car. Later I started to drive and heard a terrible noise. I checked all my gauges and nothing looked wrong but the noise freaked me out. I immediately turned around and went home. Fortunately I had only gone a little ways down the street. While I drive my oil light flickered on then off. Once home my husband checked under the hood. When he turned the car on, oil was squirting from a hose everywhere. He checked under the car and oil was all over the bottom of the car. There was no more oil when he checked the oil stick.