I would agree that oil blow by the rings and valve seals is a contributor to the problem. However, you are not going to clean anything on the fuel side of the rings and seals with your oil. Total waste of time and money.

If you want to remove carbon deposits from the combustion chamber you need to put detergent in the fuel, or disassemble the engine and manually clean it.

 

I read somewhere that the early Camry hybrids could have sticking rings. I'm not sure what this would cause. A good additive should clear that up, if that's the problem.

I filled my '07 TCH once with a bad batch of Texaco gas. My wife could hear a metallic rattle as we were driving up a overpass in the edge of town. We had the windows cracked at night for fresh air. The concrete protective walkway wall on our side of the overpass reflected the sound. I added a bottle of techron while filling the tank this time with phillips 66 gas. After 2 1/2 tanks of the phillips gas the problem was gone.

 

Where to begin.....To start with, most people understand that a higher numberical number indicates increasing the timing advance before TDC and a lower number indicates retarding the timing. I will try to be more precise in my answers for you.....

Second, yes, the ECU controls the timing but the ECU varies the short term fuel trim, long term fuel trim, injector pulse timing and duration, timing and throttle position based upon feedback over time from the sensors on the car. Over thousands of miles, this custom tune can be quite different from the factory settings. This typically happens to a driver with a light foot as the computer can advance the timing curve and run a little leaner on the fuel mixture to make the car more efficient. By re-setting the ECU to factory defaults, this learned tune can be deleted. Last of all; changing the oil will do NOTHING for valve pinging. That is entirely on the lubrication side of the engine. Sea Foam does wonders and will clean the varnish off of a sticking lifter but that is NOT the problem we are discussing. You can clean deposits from the combustion chamber by running a cleaner into the intake system or by adding a good fuel system cleaner to your gas over a period of time.

Lastly, Amsoil is a nice synthetic oil but it is not a “be all, end all” solution to anything. I happen to run Mobil 1 synthetic but I know a LOT of guys with 250 to 400 thousand miles on their cars that run dino oil and nothing else that have no problems at all.

 

Have your valve lifters checked, they are part of maintenance schedule. They could make those noise when the clearance is off the spec.

Prior to that try premium gas and check your oil level if that helps. If premium helps then it's the knock sensor.

 

Mentioning ignition, today I watched my timing today using the scan gauge when driving to town. I saw it hit up into the low 40's a few times then twice it hit 44 degrees advance. I don't remember the '07 ever hitting much over 36 degrees.

Talking about guys with the super high mile vehicles reminds me of some I read about with 380K miles. Their secret was changing the dino oil ever 2000 to 2500 miles. One fellow I met with 225K on his old pickup said he changed oil every 2000 miles and filter ever other time.

I'm also using mobil one which is a very popular oil used in all racing. I'm sure it's a different formulation that used in or passenger cars. I used the 0W-20 weight all the time I owned the '07 TCH. I will change to it again on my first oil change at 5000 miles with this new '12 TCH. I will stick to the 5000 mile change due to the dust we have here during the March winds, then again in July during our 'rainy season' from the nearby storms.

 

Actually most "synthetic" oil sold to consumers in North America is dino oil too. It is just more highly refined with processes such as severe hydrocracking and/or hydrolsomerization. Mobil sued Castrol in 1990, claiming their group 3 oil sold as synthetic was really dino oil, as it was made from conventional oil. Mobil lost the lawsuit, and since then group 3 oil can be sold as synthetic in North America. And most synthetics are probably group 3, or a group 3 blend, including Mobil 1. If you want pure group 4 and/or group 5 synthetic, about the only sure way is to buy oil sold in Europe that is marked synthetic. Some Amsoil and Redline, and perhaps a few other specialty oils are group 4/5 synthetics, but often they are not API qualified.

But we are off track as combustion chamber deposits are not caused by the type of crankcase oil used. They are not caused by gasoline either. It is the amount and effectiveness of detergent additives in the gasoline that is the main factor.

 

That's good information about the synthetic oils and I do remember the Mobil One vs Castrol lawsuit.

Your right, it's the extra detergent additives in the gas that keeps the engine deposits from forming. This is another reason to use a top tier gasoline which has near twice the additives of the government's recommended basic amount of additives in the 'non' top tier brands of gas.

 

Amsoil Engine Flush page says to idle the car for 10-15 minutes. I see you recommend driving with Seafoam for 500 miles but have you driven yours for 500 miles with the Amsoil Engine Flush detergent in there? I have seen instructions for a "maintenance mode" on GreenHybrid to get the car into idle.

I see some deposits on the oil dipstick and want to try Amsoil Engine Flush.

Any others that have experience using Amsoil on their TCH?

Thanks.