Originally Posted By: GT Mike
Carbon knock is a possibility, but since it seems to dissipate as the temperature increases, that might not be the most plausible explanation.
I shudder at doing a top engine cleaning on an engine with an inverted long-runner plenum such as this engine has due to the fact that any liquid could puddle up in the bottom and get suddenly get sucked into one cylinder. I'd rather live with a little knock than hydraulic a cylinder. Unless someone has a fool-proof method, I'd be interested in listening...
Note that in our case it was quite loud at cold start and quieted down quickly as it warmed up... sound familiar?
2 cups of Kreen in the gas quieted down our GM V8's in just a few minutes when we figured out we had carbon build up. I definitely do not like putting any liquid into a 'dry' manifold these days for the exact reasons quoted.
Many of the common gasoline additives can help with carbon knocking, but it is tricky to be sure if you have it!
Carbon knock is a possibility, but since it seems to dissipate as the temperature increases, that might not be the most plausible explanation.
I shudder at doing a top engine cleaning on an engine with an inverted long-runner plenum such as this engine has due to the fact that any liquid could puddle up in the bottom and get suddenly get sucked into one cylinder. I'd rather live with a little knock than hydraulic a cylinder. Unless someone has a fool-proof method, I'd be interested in listening...
Note that in our case it was quite loud at cold start and quieted down quickly as it warmed up... sound familiar?
2 cups of Kreen in the gas quieted down our GM V8's in just a few minutes when we figured out we had carbon build up. I definitely do not like putting any liquid into a 'dry' manifold these days for the exact reasons quoted.
Many of the common gasoline additives can help with carbon knocking, but it is tricky to be sure if you have it!
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