Have checked my timing belt multiple time at 305° and verified that my timing chain is in perfect position. All 4 stamp circles show up centered-after 121k miles. I put it down to good oil changed every 3-4 k. I know this is excessive but for $50 including fleese filter why not. My question is this: if I want to change cam hydraulic lifters do I have to remove camshafts. I want to change all the lifters as one is lightly ticking. I also get a mild engine vibration that begins at 2.2 k rpm underway, and even in neutral. I want to change the lifter for this issue I and then next the tranny and motor mounts. Any guidance would be well appreciated. Thank you!

Welcome! Please post a photo of the E350. Try also posting in the E-class section for your vehicle. Knowledge owners can see the question and provide input.