About six months ago, I started hearing pinging upon light acceleration at between 20 and 30 MPH. Pinging varies from light to very bad and is worse when under light or moderate load/incline and when weather is warm. Pinging has occurred across many tanks of gas of different brands---top-tier and non-top-tier.

Dealer (Magnussen Toyota, Palo Alto, CA) was dismissive but did say that the issue is coming up more frequently with TCH's. They advised higher octane gas (not the right answer).

Anyone else out there with this problem?

In the following order as necessary:

1. Run some injector cleaner through for a couple gas tanks ;

2. Disconnect the battery for a couple minutes and let the ECU reset;

3. Seafoam to remove combustion chamber deposits that increase the compression ratio.

 

In the following order as necessary:

1. Run some injector cleaner through for a couple gas tanks ;

2. Disconnect the battery for a couple minutes and let the ECU reset;

3. Seafoam to remove combustion chamber deposits that increase the compression ratio.

The proper way to put Seafoam thru, is to find a vacuum hose and have the engine suck it up into the intake manifold until the engine dies and then let it sit for at least 15 minutes. Then start it and run the hell out of it while it will be blowing white heavy heavy smoke all over the place. This is what I do with my Lincoln Mark VIII, I go out of Town and pull off the side of the road and then when it is done and 15 minutes has elapsed run it like hell down the highway.

 

Interesting... you know this engine doesn't have traditional pistons, etc? I'm curious as to why you'd get "pinging?" This is basically a rotary engine.

 

I'm sure the 2.4l 2AZ-FXE engine used in the Camry Hybrid is basically a reciprocating 4 cylinder engine, not a rotary.

from Wikipedia:

The 2AZ-FXE is a variant of the 2AZ-FE. It has the same bore and stroke, but has a higher physical compression ratio of 12.5:1. The net result is that the engine has a greater effective expansion than compression – making it Atkinson cycle, rather than the conventional Otto cycle.
The reduction in cylinder charge means reduced torque and power output, but efficiency is increased. This combination makes the 2AZ-FXE suitable for use in hybrid vehicles, where peak torque and power demands can be met by the electric motor and battery.
Maximum output when used in the Camry is 147 hp (108 kW) at 6000 rpm with 138 ft·lbf (187 N·m) of torque at 4400 rpm.

 

Pinging cured

07 Camry Hybrid:

I had the pinging using 87 octane happen about a year+1/2 ago during warm months, under same low-speed conditions.

I switched to running the car on 89 for a year. Then last summer, I switched back to using 87 octane. No more pinging. Same great fuel efficiency.

Occasionally I would make (fully warmed engine) a hard acceleration run on the highway. I think this teaches the e-brain what the timing advance limits are.

I am not sure why the hot weather pinging stopped, but it did.