Should I MotorVac? Have Pinging

[Geo]

I have an Impala SS and was wondering if I should be doing a MotorVac treatment to the motor as it knocks and pings whenever I run it on 87 and sometimes on 89. It's ok with 92 but the LT1 engine called for 87 minimum so it shouldn't knock and ping with 87. It has 65K on the odometer. One mechanic told me to run it really hard on 94 on a highway for a small journey and see what happens. I did and even put in Techron treatment and STP Fuel treatment and then after a while when I started using 87 all the noises came back. I wonder if the MotorVac would fix it. I'm thinking that there is caked on carbon deposits on the pistons and the MotorVac would clean this.

A buddy of mine said that MotorVac is bad as it will cause the carbon deposits (and other junk) to flake off my pistons (and from wherever else) and would end up folating around in my motor and won't come out. He also said that it is a blessing if I have carbon deposits on the pistons and the requirement to use higher octane would result in better power output from the higher compression. I don't know if this is accurate thinking on his part. If what he is saying is true, then the deposits could still get worse and then the 92/94 grade will be useless too. I think I just want my motor running how it did stock without the pinging on 87 fuel and If I wish to use 92 I can if I so choose but not becuase I need to.

Thoughts?

[Warpath]

Start by sticking with 92 for a while. Some gas companies add cleaners to their high octane fuels. Try to find one who advertises so. At least while you try to figure it out, you may gain some ground cleaning the engine. I don't know if these cleaners are affective.

How to the plugs look? Do they look like they were run lean? The headers may have a lot of build up in them too. They may be easier to remove than heads. You may learn something.

I don't know what a motorvac is. But, from what I interpret, I don't like the sound of it. It sounds like a scrubbing vaccuum for inside your engine. If so, I wouldn't be surprised that some left over particles are left inside and get trapped between the cylinder and rings which could reek havac.

[merc406]

Depending on where you live you may be getting winter blended fuel, it'll run like crap, wait a few weeks and see if the problem goes away as the oil companies are switching over now.
If the problem doesn't go away look to see if the gas your buyin has ethanol and at what percent, that'll do it to.

[Geo]

Warpath: MotorVac is http://www.impalassforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=33&t=002148

http://www.estey-hoover.com/MotorVac/welcome.htm

http://www.impalassforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=33&t=002148

http://rjsautoandtruck.com/Rjmotvac.html