I recently spent a small fortune having my P6 recomisioned, the garage got it thru the MOT, but said the noisy tappets were down to a worn camshaft. I have a workshop manual, so set about the work myself, I purchased a new camshaft and lifters, after stripping, found a broken pushrod, after a thorough clean I started putting it all together. upon starting, I found I had no oil pressure, I stripped again, cleaned the rocker shafts inside and out, and reassembled. This time the oil light went out, then the pressure came up, however after warm up, and slight revving, the tappet noise was back. I stripped again, and found a different pushrod had bent. I tried again, and the same thing, but a different pushrod. I purchased a pair of new shafts, and sixteen alloy rockers, and re assembled making sure the rockers were in the correct order, and the shafts positioned correctly. on start up, sounded great, left to warm up on idle, then a test drive. Unfortunatly, after about half a mile of normal driving, it happened again. Any ideas? why am I bending pushrods?