pinging engine

Sorry to be OCD, but ping usually is pre-ignition and still has a propagated wave front. In aviation , pre-ignition is distinguished from detonation which is a complete simultaneous explosion of the charge in the cylinder. Pre-ignition may burn valves and may melt spark plugs, etc., but you may be able to still fly the airplane. Detonation will typically blow a hole in the piston crown , blow the head gasket, or blow a hole in the head, so the engine stops in seconds and that is very serious, especially if you have only one engine. Maybe. Good luck. If ping is temp related, the Canadian weather may be cool enough to avoid it.
But If ping comes back, please have a really good, old-fashioned mechanic with a good ear drive it under conditions that will produce the ping, preferably with microphones inserted in the engine bay and near any other part that is suspected of producing the ping. The different mikes will really discriminate what part or component is producing it.
From my experience, an ignition ping is like small sleet pellets hitting a window. Thuds or knocks or rattles signify other things.