ATI damper has TDC and timing marks, but there is nothing (?) those marks can be checked against on the oil pump/timing cover. Sure I can put the engine to TDC (even, tho, it is a bit tricky without removing valve cover), install the damper and scratch my own mark on the oil pump / timing cover (so, it could be helpful (?) for finding TDC next time). Do people do this or nobody bothers?

 

not needed. No external timing marks or need for them.

 

Since its a simple press fit with no key way, doesn't matter at all.

Honestly the only things to deal with in the install is that you use an install tool and have a way to hold everything for proper torque on the bolt.

 

Yeah, I do have experience removing / installing the OEM damper (here is a photo of OEM damper installation, 2nd photo in the carousel:

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I should have installed the ATI damper at the beginning, but decided to save, since the OEM damper looked fine to me. Now I am trying to solve vibration issue at idle (no vacuum leak, afaik, STFT is good, belt tensioner is new, all eng / tranny mounts are new) and the vibration damper is my last resort.

 

Your vibration issue is most likely caused by faulty engine mounts (and/or solid mounts, i.e., poly). The ATI damper contains a high-viscous fluid that self balances when turning but I don't imagine that it will do much at idle since your RPMs are at a slow ~850.

 

You are probably right. The mounts are new, but the upper mount is aftermarket one and maybe it doesn't work like OEM. I think, I'll replace it first. But I still will replace the damper, just because