Rep Power: 0

hello all,
recently got a 2003 civic coupe, 106k miles, in pretty decent shape. had the car about 3 weeks now.
there is vibration noted in steering wheel when a/c is on, and when i put car in reverse. no cel light or code.
took it to my local mechanic, thinking the engine mounts needed replacing. he told me that engine mounts look good.
not sure where to look next? vaccum leak? spark plugs? MAP sensor?
transmission shifts fine with no issues. according to the carfax, the a/c compressor was replaced in 2017.
thoughts anyone?

 
Rep Power: 222

Ac puts a pretty decent load on the engine

 
Rep Power: 224

What is the engine speed at when this happens? Lower than it should?

 
Rep Power: 0

idle stays the same around 800-1000RPM. i realize the ac gives additional strain on engine. its not a terrible vibration, but its noticeable. no screeching or weird sounds from the compressor. idle stays pretty smooth.. im going to change out the plugs anyway and see if that makes any difference. not getting any codes or CEL light.

 
Rep Power: 0

very good point, my other vehicles in the past (corolla/nissan rogue and ford taurus) never had vibration like this though. ive been doing alot of reading on civics and apparently from what im reading.. vibration issues are common with these vehicles, last night (july 17th) i changed out spark plug. seems to have helped alot with the ac vibration.. however im still getting the vibration when i put in reverse.
even though mechainc says it's ok, im still leaning torwards the transmission mount.
have appointment next week for 2nd opinion on the vibration in reverse. it's really a great running car, and im averaging 31 mpg.