After some cooling issues being investigated, I noticed a struggle at idle and louder than usual exhaust. The leak caused low compression, stall at idle, vibration and of course the noise. Not yet repaired but quoted at least $100. The main cause was a bad thermostat for the coolant line, this caused the engine to operate at a higher temperature while still showing a normal operating temperature in the gauge cluster. Removing the thermostat was a temporary fix but it still caused a serious coolant leak and I'll be needing a new radiator and hoses.