I recently bought a 2002 F150 4.2 V6 with 105.000miles, I want to know if I should replace the timming belt and water pump? the same as you do with other cars after the hit around 70 to 100,000miles, or not need to worry about it yet?

 

Well the water pump might not be a bad idea, but the 4.2 has a taiming chain, it will stretch over time but they won't usually fail like a belt. A good test to see how much it has stretched is to remove the cam position sensor(just the plastic sensor that sits on top, leave the rest in the engine) and rotate the crank with a large breaker bar and socket about a 1/4 turn, then very slowly roll it back 1/4 turn while watching the top of the CPS(used to be the distributor). If you rotate the crank several degrees before that CPS moves it's time to replace the chain.

 

thanks for the info Tronman.