150k is recommended to check valves. 100k or 5 years change the coolant. 60-70k change the power steering fluid and flush. Brake fluid flush every 90-100k is not a bad idea either.
If you have an 03-05 time to think about replacing the oil separator and might as well do the VC cover, riser gasket, and injector harness connector o-rings because they will start leaking around the 180-200k range. 06 plus just VC cover\riser gaskets and PCV filter.