Edit: Besides oil changes, brakes, and air filters, I didn’t do any scheduled maintenance between 82k and 140k miles because I was broke.
Now that I have a little more money, I want to make sure my van stays in good shape.
What should I do to catch up?
EDIT 2: Thanks, everyone! I feel a lot better about this now. Seems like I should focus on fluids, filters (which I actually have been keeping up with), and spark plugs. Really appreciate all the advice!
I thought the whole point of getting a Toyota was that you only had to do oil, tires, and brakes?
I’m not a mechanic, but if it’s running fine, I’d say the most important things are flushing the coolant and doing a transmission drain and fill (not a full flush).
@Flann
At 140k, I wouldn’t even touch the transmission fluid.
2012 Siennas don’t need much. If you’ve made it this far on just oil, tires, and brakes, you’re doing fine.
Now’s a good time to change all the fluids: coolant, transmission (drain and fill only), brake fluid, and engine oil. Also, replace the engine and cabin air filters.
Since you’re past 105k miles, swap out the spark plugs too. You’ll probably notice a small boost in gas mileage.
@Vinn
120k is actually when Toyota recommends replacing spark plugs.
If you’ve only done brakes, tires, and oil changes, air filters are an easy maintenance item to knock out too.
Besides fluids and filters, you should check the suspension. CV axles, shocks, springs, tie rods, control arms, and sway bar links should all be inspected and lubed. New shocks and springs will make the van ride way better. If the CV axles or tie rods go bad, you could get stranded.
If you do suspension work, get an alignment afterward—your tires will last longer and you might even see better gas mileage.
@Brooke
I checked out a 2011 Sienna with 130k miles, and the engine mounts were starting to get loose too.
Just drain and fill the transmission fluid and coolant. Change the spark plugs. If you haven’t already, replace the air and cabin filters. Look through the maintenance guide to see what else you missed and catch up.
What’s the cold cranking amps (CCA) on your battery?
Rafe said:
What’s the cold cranking amps (CCA) on your battery?
Not sure. I’ve replaced it once or twice with a good battery, but it drains fast if a kid leaves a cabin light on.
Rafe said:
What’s the cold cranking amps (CCA) on your battery?
Not sure. I’ve replaced it once or twice with a good battery, but it drains fast if a kid leaves a cabin light on.
Yeah, car batteries don’t handle getting fully drained very well. Unless it’s a deep cycle battery, running it down too much shortens its life.
I’d get a good jump pack like NOCO or GooLoo if this happens a lot. They’re small, easy to use, and worth every penny.
@scofield
Good call—I have five kids, so I already got one. 
What color is the van? If it’s beige, you’re fine. Beige vans last forever.
Find a mechanic you trust and have them do a full checkup. I’d skip the dealership—service departments make a lot of money off repairs, so they might push for stuff you don’t really need.
Tell the mechanic exactly what you told us, and they’ll probably suggest a few things. If it’s running fine, I wouldn’t expect a massive bill.
A checkup wouldn’t hurt, but I’d just follow Toyota’s maintenance schedule for your mileage. No need to stress—oil changes are the most important thing, and you’ve been keeping up with those.
Spark plugs are due, but it’s not urgent. If the van drives straight and doesn’t bounce, your suspension is fine. Do a coolant flush, swap out any dirty filters or wipers, and you should be set.
Toyota makes solid cars, but skipping maintenance for too long can still cause problems. Keeping up with this stuff now will save you from bigger repairs later.
Along with regular maintenance, I’d also pay for a full inspection so you know if anything major needs attention.
P.S. If you’ve never done an alignment, I’d get one soon. It’ll help your tires last longer and improve fuel efficiency. Also, rotate your tires regularly.
@scofield
These vans have a timing chain, not a belt.
Tilden said:
@scofield
These vans have a timing chain, not a belt.
Right, I forgot—no belt to replace on this one.