 I bought a 2000 Sienna and people should know that all the 1st generation Sienna's have what are known as "sludge engines".  Toyota sent out 3.3 million letters to owners extending the warranty from 3 to 8 years because of this.  The engines are defective so join a forum before you buy one and ask about the sludge problem.  Also, from what I've read, Toyota has been really nasty and unless the car was ready to die next week they wouldn't honor the warranty extension.  Very, very few people got any warranty work done.  So it was a con job and because of this engine problem it would be wise to get a different vehicle.