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Stock Motor Knocking?

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Old 06-04-2009, 01:04 PM
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Default Stock Motor Knocking?

I have a 02 Formula M6 with 38K miles that is stock except for a K&N intake. It seems to knock whenever you go WOT. But mostly it does it at above 4K rpms. I run 76 91 octane gas. Any ideas on where to start? I have changed the plugs and wires already. Ive heard that LS1's can knock with 91 octane california gas.

Note: The SES light has never come on. The car knocked with the sock intake as well.

Last edited by LSX Performance; 06-04-2009 at 01:04 PM. Reason: added info
Old 06-04-2009, 03:00 PM
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I have an '02 SS with just under 40K miles. I only use 93 octane Chevron because I actually see a .1 to .2 sec deficet at the race track on cheaper fuels. I use a weather computer to log runs so it's pretty easy to know when things aren't right.

I'd say if my car pulls timing on cheap 93 octane gas yours could easily be having an issue with 91 octane.

Maybe you need to de-carbonize the engine.

How to seafoam your car
Old 06-04-2009, 03:24 PM
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Originally Posted by 91RS383
I have an '02 SS with just under 40K miles. I only use 93 octane Chevron because I actually see a .1 to .2 sec deficet at the race track on cheaper fuels. I use a weather computer to log runs so it's pretty easy to know when things aren't right.

I'd say if my car pulls timing on cheap 93 octane gas yours could easily be having an issue with 91 octane.

Maybe you need to de-carbonize the engine.

How to seafoam your car
I was just thinking about that. Im going to try the seafoam fuel system cleaner first to see if that works.

Have you seafoamed your car?
Old 06-04-2009, 03:34 PM
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I did use Seafoam on my Jeep not the Camaro.

A buddy of mine was an ASE certified GM Tech. He said they used to do it at the dealership he worked at but the product they used was GM Top Engine Cleaner or something similar. He said it had a GM part number so you should be able to buy it at the stealership.




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