I recently purchased a F-150 (my first ford....blush) and I really like the truck except for an annoying clicking noise. The clicking noise always clicks at the same rate and seems to be coming from the engine compartment. Here's the kicker, it only happens when there is very little load on the engine but not at idle. For example, when topping a hill and slowly releasing pressure on the throttle. The noise is very sensitive to engine load. A little extra, or less pressure on the throttle will make it go away. The best way I can describe it is, "it only happens during the transition from throttle load and coast". If I am very gentle with the throttle I can make the clicking persistant, any speed, any rpm.

 

if im not mistaking, it is your valves clicking. my truck was doing that too, try putting higher test gasoline in your truck, it solved my problem. it also could be cheap gas.

 

hmmm... I have filled up the last two times at a station that has 10% Ethenol in the gas... I'll fill up somewhere else and check it out ... thanks