Machine is 10 years old with about 8000 hours. I recently have been hearing a tapping noise coming from the right lower side. It seems to be coming from the heat exchanger area. I know it could be a few things but before I start pulling all the heat exchangers I figured I’d see if anyone has some advice as to what it might be. It definitely is noticeable when it’s warming up idling. Not so much at full throttle. Thanks for any help.