Stonepa

I have a 2002 SC430 that I have owned since new. Now has 90k miles on it so I think I might as well get the timing belt / water pump changed. No leaks in the water pump after all these years. Dealer quoted $1600. Is that reasonable? That's a lot higher than I paid for the same work on my wife's RX Hybrid or my LX. Thoughts?

KingReyes

I've literally seen 3UZ-FE (LS430, GS430, SC430) timing belt change for around $600 at any competent shop. Buy the parts online (Aisin kit) then have a mechanic put it in for you.
For dealership, that looks about right.

Jabberwock

My local Lexus dealer replaced WP, TB and serpentine belt at 90k miles for approx $1150 - and they let me use a 10% off coupon to lower that cost a little further.
Try your local Toyota dealers - call and tell them you are shopping for best price and ask them to give you their lowest cost including any coupons or "specials" they can offer. Then call local Lexus dealer back and ask them to match or beat the estimate from Toyota. Depending how busy they are a dealer will compete for your business if you ask them to do so.

StillLine

Total cost was $960. 2006 SC430 with 62,000 miles. Replaced timing belt, water pump, idler pulley, tensioner pulley, tensioner, thermostat, accessory drive belt and coolant. Labor was $525, parts and coolant was $435. I kept all my business local by purchasing the 3 gallons of premixed coolant at the local Toyota dealership, parts at the local NAPA, and labor at the independent mechanic's shop across the street from the NAPA.