Riptide711

When should we start thinking about new hoses and belts?

bclexus

There is no absolute set interval on changing the serpentine belt. Inspect it routinely for cracks or wear. If it doesn't look good or if it starts to make noise, it's time to change it.

The serpentine belt is a durable component that can last for 90,000 miles or more under normal driving conditions with a recommendation to replace it at 60,000 miles in severe conditions. Severe conditions would be in areas with high amounts of sand (e.g. driving on roads adjacent to desert areas) or driving on roads with salt/brine frequently used in cold climates areas of northern states. The serpentine belt should be inspected routinely and replaced if it shows any signs of losing integrity.

Hoses (as well as wiper blades) of late model Lexus and Toyota vehicles are made of very high quality rubber that can last many years. In most cases the first sign of needing to replace a rubber hose is fluid leakage. A hose can be inspected routinely and replaced if it shows any signs of losing integrity, but in all likelihood its physical appearance by visually looking at it will not show signs of it needing to be replaced. A better inspection is by touching/squeezing the hose to determine if the rubber is soft to the point of it suffering deterioration.

4GS350

Does any company sell a whole set of the cooling hoses for the GS350 as a package?

bclexus

That might be available from an aftermarket company or on eBay, but I suspect OE hoses are only sold individually by part number.