Heck! I am even more confused now as I have been driving the car all day today and it hasn't made the noise once. After I had put one new lifter in(random choice of position) and assembled everything I ran the car until it reached quite a high temperature. While the car was running at this point, it was still making the noises although after a couple of minutes it stopped. ......... Now I have heard it make the odd "tap" while I was idleing but only a couple of taps, and only the once today. Have I done somthing right by accident? Would be nice if it didn't come back. Woz