One problem related to gas recirculation valve (egr valve) has been reported for the 2008 Ford F-150. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Ford F-150 based on all problems reported for the 2008 F-150.
We bought this truck brand new in February 2008 and the air conditioner does not blow cold at idle. It will blow approximately 70 degrees out of the vents on a 90 degree day. I have taken it to 2 different dealers and both checked and test drove the truck, only to advise "there is nothing wrong with it" it is blowing cold enough according to them on max a/c going down the highway, so their suggestion was to not change it from max a/c.