I have a 2008 Outlander 2.4L. Engine model is 4G69. It has done 130,000 kilometers.
The car is running the last 60,000 kilometers on LPG. It still uses 95 unleaded fuel to start until it warms up.
Recently I had a throttle body clean and replaced the Thermostat.
Couple of days after the car treatment I noticed the engine has Pre-Detonation/Knocking (it sounds like marbles in a can).
It happens mostly when it runs on fuel. When it runs on LPG Knocking happens only on heavy load and hot engine.
My car mechanic checked the car but told me he has found no issue with the engine and no relevant engine computer errors.
He asked me try to use 98 octane fuel and see what’s happen, didn't get to do it yet as I have to finish the existing fuel tank.
Any idea what can cause this issue?