My '88 260E makes a loud ticking sound for several seconds after starting, especially if it has not been driven for a couple days. Could this be the hydraulic lifters and can anything be done other than replacing them?

Another thing I noticed while going through the previous owner's service records is that the car was serviced 1n 1991 with 40k miles because of a clicking/ticking noise. The dealer replaced the cam and all 12 rockers due to abnormal wear on the came lobes and rockers. I have not seen any other problems with camshafts on this board and was wondering how common this problem is.