Two problems related to engine burning oil have been reported for the 2000 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2000 Toyota Sienna based on all problems reported for the 2000 Sienna.
Engine oil light came on when driving, when taken to dealer, service rep. Indicated this would potentially be a very expensive repair. After a quick search on the internet revealed an "issue" with this engine and a call to Toyota national and some "discussions" with the dealer the car was taken for "desludging". Proof of oil changes had to be provided, much discussion about how it was "our fault". Since we are both engineers and typically keep our vehicles a very long time, this was insulting. Van was returned, but oil light came on within 10 miles. It then stayed for quite a while (I think they said it had at least 6 oil changes). No offer of rental car was made. After it was returned within a month it blew a hole through the valve cover (mechanic forget to torque one of the head/cam bolts, bolt backed off and washer blew a small hole in valve cover). Oil/smoke everywhere. It burned off oil for months afterward. It was towed back. Hole was on extreme drivers side of engine. Valve cover was replace, bolt/washer either replaced or retorqued.
The caller states that the oil in vehicle was disappearing from the engine. He drove 800 miles to florida and had to put 4 or 5 quarts of oil. He has to put that much oil every 1500 miles. Dealer had the vehicle since August 5, 2005 and they could not find the cause of the problem. Manufacturer sent the caller a letter stating the engine could fail because of the oil problem. It was an oil consumption problem.