M [2017 Toyota Sienna XLE, Safety Photo] [2017 Toyota Sienna XLE, Photo] My cousin purchased this 2017 Sienna new from the dealer. Vehicle currently has 23,000 miles on the clock. Has noticed a coolant smell from the engine area since new. Visual inspection reveals seepage from the coolant overflow tank. The dealer has pressure tested and inspected the coolant system on several occasions with no leakage found. The coolant overflow tank cap was replaced at 17,000 miles and it has continued to leak/seep. Vehicle was just in for service yesterday and the dealer states, "it's normal for coolant to vent from the cap." Vehicle requires top off of coolant between services.

The vehicle also has been showing substantial tire wear on the inner edges of all four tires. Wear is otherwise even across the tread with no balance issues. Tires have been rotated per Toyota service schedule. Alignment was checked at the dealer and reported as 'in spec,' I do not have access to the printout. Vehicle is all wheel drive and has run flat tires. I have personally observed similar wear patterns on Audi Quattro vehicles fitted with run flat tires and correct alignment. Might just be characteristic of an awd vehicle with run flat tires?

I don't service many Toyota vehicles. Curious to hear what other techs are seeing in the field on these Siennas? He is more concerned with the coolant usage rather than the tire issues, and would like to have it addressed while the vehicle is still under warranty.

Pictures of concerns attached.

Thanks in advance for all responses.

Kevin Cullen
Technician
Kevin Cullen
Danbury, Connecticut, USA

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