See also:

Engine Cooling when Trailer Towing
The cooling system may temporarily overheat during severe operating conditions. See Engine Overheating. ...

Engine Drive Belt Routing
3.9L V6 Engine 4.6L V8 Engine ...

Footnotes — Maintenance Schedule Additional Required Services — Severe
a) Or every two years, whichever comes first. b) Check all fuel and vapor lines and hoses for proper hook-up, routing, and condition. Check that the purge valve, if the vehicle has one, wor ...