Did a few kms in the car this week. Should have looked under the bonnet more as a small oil leak from somewhere yet to be determined made a mess under there.
After a couple full throttle runs near home we heard a small ‘tinkle’ sound followed by a noisy rocker sound. After previously throwing out valve caps before it was likely this had happened again. I decided to take a look myself so pulled off the passenger side rocker cover first (as its much easier to remove than the driver’s side) and one valve cap had indeed come out and was still safely nearby in the valve train area.
Some quick phone advice thanks to Jake and I felt confident enough to complete the repair myself. Everything went smoothly. Discovered another advantage of a mechanical fan; you can rotate the motor with no extra tools required. This allowed me to confirm that everything was back the way it should be so we went for a test run and all was good!
Also replaced the lpg safety switch to see if that stops an annoying intermittent buzzing/clicking from under the dash, only time will tell for sure.