Yet another Lifter Problem!

[groel220]

Hello, all! I recently bought a 1999 S80 T6 that was non-running. I replaced the ETM with a Xemodex model (which seems great so far!) and now it starts and runs every time. It does, however, have some loud lifter tick on the passenger side of the engine. It sounds like it may be only coming from one lifter, but it is persistant and does not stop even when my car is fully warm. I have tried putting heavier oil in and even recently replaced the o-rings in the oil pan in hopes of solving the problem, still no luck. In my hours of searching I found a suggestion of a loose lifter perhaps being the culprit, but I thought these were self-adjusting lifters, so they shouldn't be loose, right? I've seen mixed reviews of adding seafoam to the oil and don't want to do anything that is going to hurt my engine. Is there anything else I can do in order to check/fix this problem? In the meantime, is this hurting my car or engine to continue driving like this? Thanks for any input!