Scotty, I've heard that the transmission cooler line connector to the radiator on my Sienna can corrode causing the coolant to leak into the transmission, causing it to fail and that I should replace my radiator (appears original, says Toyota) as a preventative, is that correct?
please post your odometer. Thanks.
185k miles.
Normally, no this does not happen if you keep up on maintenance. Replacing the radiator preventively is not a thing.
But if Toyots has known radiator defects, then that would be another story.
I was told by other 2nd gen (04-10) Sienna owners that this is a known flaw in the original factory radiators. And it goes for the 3.3L (04-06) and the 3.5L (07-10) as well.
OK I see that now. In fact Toyota issued a warranty extension campaign for it (which has concluded). Are you the first owner? If the radiator hasn't been replaced before, then yeah I guess you should. A new radiator is much cheaper than a new transmission.
No, I'm not, but the original owner didn't appear to have had it replaced either according to service history. I probably will just replace it this summer anyway.