Engine clatter (fuel knocking)

[edthefox5]

Originally Posted by Patrick Wong

I've noticed that both my 2001 and 2004 had slight ping when going uphill, especially in the summer when using California-formulated gas.

However, when driving the 2004 in high altitude areas in the Mountain West where 85 octane fuel is sold (i.e., Utah, Colorado), I've used that octane and have heard absolutely zero ping.

Now that the 2004 is in Arizona, I don't hear ping. I suppose the gas there is better (compared to CA), not to mention cheaper.

Odd that you will not ping on Rocky Mountain formula 85 AKI but will ping on California 87. But...much thinner air in the Rockies..less combustion..but I still would think since Gen II car's are tuned to 87 it should never ping. Somehow the OP's car is unhappy with 87. Have not recalled another ping complaint in the 2 years I'ver been here on a GenII car.Have never ever heard a ping on 87 with my 07.

[jyoungprius]

Not sure what fixed the problem, but I refueled on Sept. 9 and had the quick lube place drain off enough oil to bring dipstick level down to normal level a couple of days later....pinging sound is now gone.

[Manjusri]

Have been driving a 2010 for about two weeks (1k miles) and noticed a rattle from the engine compartment when the combustion engine is running. The tech called to say that this is a normal sound. I'm not so sure.