I pulled out the first three lifters and one of them I could push the top of it down a little - the other two were solid as a rock. It would push down just a tad but would spring right back up. I checked all the old ones I had pulled out and all but one of them was solid. I'm guessing the one -the new one - that I could squish down the top of is my bad one. If that is so what would cause a new one to go out in just 30 miles and could it be related to why the old one went bad?