The last of the good six-speed years — buy it for the drivetrain, inspect it for the doors.

Separate from the recall, the third-generation Sienna's door hardware has four recurring failures, and Toyota has bulletins for all of them: the cable that pulls the door can snap (you will see it dangling above the rear tyre and the door stops working); the centre hinge corrodes so the door jams just as it finishes closing; and the front or rear lock assembly seizes, so the door will not latch. A class-action settlement produced what Toyota calls a Customer Confidence Program — a quiet extended-coverage scheme run outside the normal warranty — under program code ZKI, plus two Warranty Enhancement Programs, ZH4 for the front lock assemblies and ZH5 for the rear. The terms are stated in Toyota's own bulletin: cable sub-assembly, centre hinge and fuel-filler door are covered for '10 years from the subject vehicle's date of first use, regardless of mileage', and ZH4 and ZH5 run nine years from first use plus one additional year, also with no mileage cap. On a 2016 van that clock is at or past its end, so treat these as your cost from here, not Toyota's. Our mechanic source's standing advice is to call a Toyota dealer and ask about extended policy coverage before paying anyone — and a long-term owner in our sources had the latches replaced at around 50,000 miles and watched the same fault return by 85,000.

The independent Toyota mechanic in our sources is blunt about this engine: 'overall it's a great engine, however it is notorious for oil leaks, head gasket leaks, coolant leaks.' Three checks matter on a 2016. The front timing cover — the cover over the timing chain at the front of the engine — leaks oil, and he calls it 'a very, very expensive repair'. His inspection method is simple enough to do yourself: go under the van from the passenger side by the front wheel, look up, and confirm the area is completely dry. Second, the head gasket can leak coolant externally, which needs the engine dropped; he says 'it seems like the Sienna happens to be the worst for this leak, we've done so many of them,' and scopes it to 2011–2016 vans specifically. Third, the water pump both leaks and develops a bearing rattle that rises and falls with engine speed; a second source says the 3.5's water pump commonly leaks before 100,000 miles. None of these carries a Toyota program. Have a mechanic put the van on a lift before you buy — the head gasket leak is not visible from underneath on the ground.

2016 is the last Sienna with the six-speed automatic. From 2017 Toyota fitted an eight-speed (the UA80), and it produced the single largest complaint cluster anywhere in this van's recent history — a whine that builds into harsh shifting and then failure, with owner-reported replacement quotes in five figures. None of that applies to a 2016. Our mechanic source's guidance for the six-speed is maintenance, not repair: change the fluid roughly every 60,000 miles or six years and 'you should have no issues'. Ask for that service record; Toyota's schedule does not push it, so many vans have never had it.

Treat suspension as a running cost on this van rather than a repair. Our mechanic source says leaking front struts are close to universal — 'almost every other one I get in the shop' — and explains why the strut mounts rot: water running off the windscreen collects in the cowl and sits directly on top of the mount. Salt-belt vans add worn sway-bar links to the same job, and he has seen mounts separate completely. He also flags front lower control-arm bushings wearing 'at an alarming rate', with a test you can run on a test drive: at low speed, take your hands lightly off the wheel and brake hard — if the steering wheel jumps sharply to one side, the bushings are worn. Rear coil springs cracking is a rust-belt-only item worth a look underneath.

All-wheel-drive third-generation Siennas have no room under the floor for a spare wheel, so they leave the factory on run-flat tyres. Both of our owner-side sources are unhappy about them and their numbers differ, so here are both: our mechanic source says expect uneven wear and replacement around 30,000 miles; a long-term owner of a comparable third-generation van says roughly 10,000 miles per set at about $1,000 a set. Either way it is a real recurring cost, and the mechanic's recommended workaround is to fit conventional tyres and carry roadside cover instead. Separately, the all-wheel-drive system itself gets a clean bill of health from him — 'a great system, bulletproof' — with one cheap wear item: a mount at the front of the rear differential that fails and produces a loud clunk or rattle from the back under hard acceleration. Toyota has a bulletin for noise from that same rear-differential coupling.

Recall 16V-197 (Toyota code G0H) covers a narrow build window in February 2016 where incorrect front seat-belt height adjusters were fitted; in a crash the wrong adjuster can contact the B-pillar and tear or separate. Free replacement. Three of the other recalls on this year are not Toyota's at all — they belong to companies that convert Siennas into wheelchair vans: Braun (19V-410, brake-line fittings), Vantage/AMS Genesis (19V-553, rear brake hoses that rub the trailing arm), and Rollx (25V-876, wheelchair-restraint retractors that may not lock). A large share of used Siennas are conversions, so if the van you are looking at has a ramp or a lowered floor, run the VIN and check those specifically.