engine pinging: anyone else have this

Most of the normal fuels in the U.S. do the same thing. I pulled my plugs at 120,000 and hey looked great.

 

I'm just back from the Toyota dealer with my 2010 IV (25,500 miles) that has the same pinging sound. Mine happens when the engine is hot and under a load like going up a hill at highway speed (50+) and as soon as I back off the gas it stops. I was also unable to have the engine make the sound for the Dealer but I did have and Iphone video of it. Turns out it was a complete waste of my time. They seem to think it is a missing clip on a splash shield and they ordered the part for me. Over the past month I've tried Shell 87, 89 and 93 with no change.

 

I'm just back from the Toyota dealer with my 2010 IV (25,500 miles) that has the same pinging sound. Mine happens when the engine is hot and under a load like going up a hill at highway speed (50+) and as soon as I back off the gas it stops. I was also unable to have the engine make the sound for the Dealer but I did have and Iphone video of it. Turns out it was a complete waste of my time. They seem to think it is a missing clip on a splash shield and they ordered the part for me. Over the past month I've tried Shell 87, 89 and 93 with no change.

 

The idea of putting 87 RON into a Prius struck me as odd until I realised the difference between Research Octane Number (RON) used in Australia to AKI used in the USA.
AUS Regular RON 91 - USA AKI 87
AUS Premium RON 95 - USA AKI 90-91
AUS Ultimate RON 98 - USA AKI 93-94

Shell sells E10 RON 94 in lieu of RON 95.

 

Try running a bottle of Gumout Regane through. Snake oil usually doesn't work, but this stuff has a good track record.

There are other possibilities: The knock sensor is not working, or your oil control valve is partly plugged.

 

I have the same thing on my 2010 with 9k miles. It sounds just like spark knocking / pinging... It actually sounds like a small electrical arch... Has anyone else had this?

 

I have the same problem on my 2007 with 146000 miles and I think its coming from the transmission or trans axle. This is why i think its the transmission when the noise starts took my foot of the gas and slowly put it back on with little pressure on the transmission and the noise either stop or was less.

 

Suggest letting your gasoline go down to about 1/4 tank then put a container of Chevron Techron in it at the pump the fill up the tank and run until it is down to 1/4 tank and see if that helps. If it does not help it sure won't hurt anything. My 2011 Prius has on occasion made knocking noise when I start it up and adding Chevron Techron fixed the noise. It would be a cheap try for you