Knocking Sound Comes, Then Goes
Odd one for the group. When I start my engine after the car has been idle for a bit, I get a dull, deep knocking/thumping sound from the engine compartment. Pretty sure it's the engine itself, but oddly, the knocking always completely disappears after the engine has run maybe 5 - 6 seconds, and doesn't reappear until it again has set a while. Advance stays retarded the whole time. What would cause the noise to disappear? Oil circulation would seem the logical reason for the end of the knocking, but would it subside that quickly?
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