I’ve owned a '98 Sienna in Texas, and man, the A/C’s on its last legs usually. My dad’s Sienna back east had tranny issues too. Common problems, but with TLC, they can be managed. Funny how those engines hold up though! Could probably drive forever still, except for the niggly parts, of course. But that’s what makes the Sienna a charm for a modder!
I had a 98 Toyota Sienna in Toronto, and man, the AC system—terrible! Had to replace it every other summer, felt like passing a buck. Also, age catches up—thought the motor was decent until a head gasket failure hit. Everyone around mentioned similar issues. If you spend too much time in the clutch or gas, surprise surprise, you’re ready for that routine tune-up ritual!
I’ve had my fair share with the ‘98 Sienna drivin’ up in Seattle. Thick A/C problems, things gettin’ real hot quick. And headlights almost went kaput ova night! Engine sputtered a few times too. Anyone else? Fixin’ those be a hassle!
I’ve had a 98’ Sienna too in Ontario, Canada. Fun ride but had issues with the timing belt on top of the usual wear and tear like transmission hiccups. Ah, good times. 
