need new lifters...
I put in a xe274 last year and had a couple of lifters go bad right away and called comp and they said send them in and they'd test them and if they were bad they'd send me new ones. I was kinda leary because I hadn't ever had this happen before and thought maybe they'd try and rip me. But I have to give them credit they sent me new ones right out no problems and they were much better than the originals (even looked slightly different) and I had no problems with them other than the typical noise like Moper described which is normal.