I recently purchased my 01 Civic and only had 64,xxx miles. It has around
75,xxx miles now. It all of a sudden started pinging/pre-detonating out of nowhere. I first just figured was bad tank of gas. Problem remained and then tried higher octane and still remained. I then started worrying as I know this is not good on the engine at all. It has the COP system so I know there is no issue of distributor bolt loosening and timing getting advanced. There is no check engine light on. I don't know if it isn't as good on gas or it's in my head but it seems like it may have went down some. I was thinking maybe the cam sensor or knock sensor but figured it would throw a code. I really can't see the timing belt slipping with such low mileage. Any input or advise you can give is appreciated.

 

That's usually caused by excessive engine heat, check the coolant system. Also check the spark plugs and EGR.

 

Higher octane gas could potentially screw things up even more.....