LONG POND - It wasn't the kind of day Sprint Cup points leader Carl Edwards was hoping for.

Before 60 laps were run on Pocono's 2-1/2 mile tri-oval, Edwards was forced to put his No. 99 Kellogg/Cheez-It Ford Fusion in reverse on pit road before taking it back to the garage area.

He eventually returned to run one more lap and finished 37th in Sunday's Sprint Cup 5-Hour Energy 500.

"One of the valves got in an argument with something in the engine and lost," he said in the garage area as his crew worked to try and get him back in the race. "We broke one valve. We don't think it was from an over rev or anything, we just think it was a parts failure. This is a great car and a great engine.

"We were running really well and I was babying the engine a little bit and not shifting too much. It is just one of those things.

"There was no warning at all, it just went."

Edwards didn't think that the shifting NSCAR allowed the teams to do this weekend had anything to do with it.

"No, I don't think that had anything to do with it," he added. "I was trying really hard to be easy on the engine and only shifting in one and two. This is racing I guess. What good is the point lead if you don't use it?

"This track is very taxing on everything. Our engines have been just flawless for a while. Every once in a while you are going to have a failure and we have been running well enough that hopefully we can absorb the failure."

Edwards saw his points lead drop from 40 to six with defending champion Jimmie Johnson closing in. Dale Earnhardt Jr., in third place, closed within 10 points.