67 C10 Pinging Sound

[Steeveedee]

Originally Posted by Metaldoc

Yes the choke plate should be vertical. The pop you hear is air being sucked in the bad gasket, mixing with unburnt gas, add a hot spark from the headers and pop pop pop. A mini explosion.

That's what I was thinking, up until he said he had the same noise after the collector gaskets were replaced. It may well be, as mentioned, that the collector seal is still compromised. OP- you might try wrapping several layers of aluminum foil around that joint, as a temporary check that the leak is the problem. Easy to put on, easy to take off, so an easy test for a cure.

To answer the question about carbon traces in the cap for the OP, you should be able see light carbon marks in the distributor cap, if that is the problem. The center carbon electrode may be ground up by a misaligned rotor electrode. Not saying this is the problem; it's just something to check for, since this noise is pretty random.