yesterday i was on the highway for about 100 miles running at 85 mph. i stopped somewhere for about 10 minutes when i started truck up it kept dying immediately after i started engine. it did this about 8 times. the check oil pressure light came on.it finally ran after about 5 minutes. it was idling really rough at stoplights. i made it to my dr's appointment and truck sat for about 45 minutes. i then drove home on the highway again 100 miles at 70 mph and it ran perfect. could this be a serious problem or did i run it too hard?