Need some ideas from the guru’s in here. I have a rattle from my engine. I think it is pinging.
It happens on regular unleaded, it doesn’t happen on premium.
It happens under load.
Car is m100 sirion, 3cyl.
I run it on premium mostly. recently had engine mounts and cracked alternator brackets replaced, thought the rattle might have been one of those things so I switched to regular unleaded. It started to ping right away.
I bought some octane boost/injector cleaner and the ping stopped almost as soon as the fuel in the tank made its way to the engine.
My parents bought the car new. It mostly did short runs with long periods sitting around. I thought the injectors might have some deposits clogging the spray pattern. I have run a lot of injector cleaner through over a period of time with little change.
I have read a while ago sometimes carbon buildup can increase compression if its bad enough. The exhaust disintegrated a while ago, i don’t know how long it had been slowly failing for but i heard many years ago that the increased backpressure can eliminate the factory scavenging and lead to carbon buildup.
Just after some thoughts on things i can try. I’d rather not go to the length of opening up the engine as I don’t have the time these days. If needs be i’ll just keep filling it with premium.