I'm so glad I finally found others having the same problem. My dealer claims they've never heard of such a think in a '07 TCH.

My problem is the exact same as everyone else's... only happens after car is warmed up, happens under light acceleration 25-35 mph. It is actually happening a little more now too. I will hear it with light throttle on the expressway, and it if starts to ping around 25 mph and I really step on it it just gets louder. I actually have to take my foot off the gas and then step on it again for it to go away. I've tried 89 octane gas (vs 87) and it doesn't help. I refuse to have to put 93 octane in as the car was designed for 87.

My car now has 80,000 miles and this is driving me crazy. I did buy it used with about 60,000 miles so maybe the computer does need to be reset as a couple have mentioned. Gas mileage is pretty good (averaging 38.5 - 39) on the nav screen (which is about 2 mpg optimistic) with synthetic 5W20 oil.

Has anyone determined if leaving the battery disconnected will reset the computer? I'm assuming we're talking about the small start-up battery.

 

If it's a spark knock or ping that may be gas related. I advise all to use a gas listed on the www.toptiergas.com/ web page under the link Retailers. Best to watch the video first.

I had the ping only when going up a overpass at 35 mph. My wife could hear it as her window was open some and the sound was reflecting off a concrete guard on the overpass.

She reminded me I had switched from Chevron to a lower priced Texaco station that was a truck stop. I had talked earlier to a tanker truck driver getting ready to fill the tanks at the Texaco station. He said keep this to yourself, but this is really Chevron going into these tanks. It was a year later I tried the gas at that Texaco station. They had just replaced all their underground tanks with the new thick fiberglass type. Evidently I got some bad gas or something in those new tanks caused my engine to ping. After a two tanks of the Phillips 66 gas (86 octane) the problem went simply went away. I did add some Lucas injector cleaner to the two tanks. My wife used to use it in her old Ford Ranger V6 pickup.

It was farther to drive to buy the good Chevron I had been using. I looked at www.gasbuddy.com/ using my zip code and found a Phillips 66 station also on the top tier list that was almost as cheap as the government based gasoline's. That was many years ago and I still use that same pump and station ever time I fill my tank.

Did you know that Chevron and Texaco are the same oil company. Conoco/Phillips 66 and 76 are also the same company.

The only other problem I can think of with the ping might be the iridium spark plugs. They supposed to last a long time, about 100K miles, but some have replaced them early around 65K to 75K and have eliminated engine some problems. These plugs use coil over plug technology. The coils would have to be removed to get to the spark plugs. I would recommend using Nippon spark plugs for your TCH if you decided to replace them. Nippon makes many high quality parts for the Synergy system in you car.

 

Not sure if it will make you feel any better, but the 2012 TCH manual has this statement in the Specifications section, page 486.

"You may occasionally notice light knocking for a short time while accelerating
or driving uphill. This is normal and there is no need for concern."

And occasional light knocking means your engine is getting all it can out of that level of octane, and your mileage is being maximized.

 

Interesting, thanks for the input.

 

That is interesting. So, Toyota considers a damaging condition normal operation?

 

Occasional light knocking is not considered harmful. I would check the knock sensor though. You should be able to burn regular gas in a new car designed for premium octane. The knock sensor should detect the knocking and retard timing to prevent it. Same in a car that is designed for regular but has carboned up to the point where compression has increased. The knock sensor should prevent it. You may find this video from Costco, on their Clean Power fuel additive to prevent/reduce carbon interesting. Shell puts this much detergent in their V-Power premium grade, but Costco (at designated stations) puts the same amount in their regular octane grade.

 

From the XLE manual.

If your engine knocks

Consult your Toyota dealer.

"You may occasionally notice light knocking for a short time while accelerating or driving uphill. This is normal and there is no need for concern."

Ron is right, that's the exact words is say's in the manual. pg 485.

Pg 484
Cleaner burning gasoline, including reformulated gasoline that contains oxygenates such as ethanol or MTBE (Methyl Tertiary Butyl Ether) is available in many areas.

Toyota warns not to use any ethanol or flex-fuel other than a 10% max blend. E10 should be ok to use. Any gasohol in your vehicle be sure it has a octane rating no lower than 87.

Toyota does not recommend the use of gasoline containing methanol.

Toyota recommends using the use of cleaner burning gasoline and appropriately blended reformulated gasoline. These types of gasoline provide excellent vehicle performance, reduce vehicle emissions and improve air quality.

 

I still can't get over how lean these engines run and still I never hear a knock. One would think when the engine is cold it would tend to cut out but no it runs just fine.

 

Jimmy,

While the engine is cold, it runs in open loop mode and is in a "rich" fuel burn and does not look at the O2 sensors or other sensors on the car (other than the MAF and ambient air temp). Once the engine warms up, it goes into closed loop operation and leans back out again to roughly a 14.64 air/fuel ratio.

 

I will set my scan gauge which can monitor the closed/open loop operation. It should be interesting to see how far from the house I can drive to see it closed. I messed with the loop monitoring when I first bought the '07 TCH. It would open about 3 miles from the house when I was on the highway to town. I didn't know what the loop actually did and now I do, thanks GeorgiaHybrid.