March 25, 2010
By Chris Chase
It could be argued that the Toyota Sienna was the company’s first “mainstream” minivan, its predecessors – the oddball Previa, with its engine mounted under the floor, and the even weirder Toyota “Van” that came before it – being anything but ordinary. The first-generation Sienna, then, was about as mainstream as a minivan got: following the conventional minivan formula, much of its platform and drivetrain were borrowed from a family sedan (the Camry).
The second-generation model was introduced in early 2003 as a 2004 model, with more size, more power and a more distinctive look. The powertrain was a 3.3-litre V6 (230 hp/242 lb-ft) mated to a five-speed automatic transmission. The Sienna was a rarity in offering all-wheel drive, something only and handful of minivan did at a time when the SUV/crossovers craze was in full swing.
The second-gen Sienna’s first major update came in 2006, when it got the requisite mid-cycle styling update. The SAE’s new horsepower rating standard meant the 3.3-litre engine’s rated output dropped to 215 hp, though this didn’t affect its performance. The second update followed in 2007, with the replacement of the 3.3-litre engine with Toyota’s newest 3.5-litre V6 (266 hp/245 lb-ft). 2008 models got standard traction and stability control across the line; the Sienna would soldier on through 2009 and 2010 with updates to its standard feature and option lists.
2004 Toyota Sienna CE; photo by Grant Yoxon. Click image to enlarge
In 2006, the Sienna’s Natural Resources Canada fuel consumption ratings were 12.4/8.2 L/100 km (city/highway) in FWD form, and 13.5/9.4 with all-wheel drive. Newer (2007 and up) models with the 3.5-litre engine were rated at 11.7/8.1 L/100 km with front-wheel drive and 13.3/9.5 with AWD. Note that the all-wheel drive model’s real-world fuel consumption tends to be higher than the ratings suggest, though: a 2007 all-wheel drive model I drove averaged higher than 17 L/100 km, and CD.com blogger James Bergeron drove the same van to a 14.5 L/100 km average in mostly highway driving, both numbers quite high, even in the frigid winter conditions Ottawa was experiencing around that time.
Like most Toyotas, the Sienna has a strong reputation for reliability, but it’s not bulletproof.
2005 Toyota Sienna CE AWD, top by Grant Yoxon; 2004 Toyota Sienna LE, courtesy Toyota Canada. Click image to enlarge
A rough-shifting transmission is common in older models with the 3.3-litre engine. The problem is electronic, rather than mechanical, and according to Sienna owners posting at SiennaChat.com, can usually be fixed by “re-flashing” the transmission control unit. Read here and here for more information.
Power sliding door failures are common, too, according to both SiennaChat.com and Consumer Reports. Here are two downloadable technical service bulletins (TSBs) (one and two) from the National Highway Traffic Safety Administration (NHTSA) in the U.S., and here’s a very handy thread at SiennaChat.com about the sliding door problem.
The hydraulic struts that support the tailgate when it’s open are weak, according to Sienna owners. It’s common for these to perform poorly in cold weather (especially after a few years of use), but owners posting at SiennaChat.com seem to think the struts on their vans are particularly bad.