[QUOTE]Originally posted by Archon
[B]Thanks for the info.

 

All cars with aluminum engine components and ancillaries (block, head, radiator, etc.) pop and crack while they cool down. It is because of the cubed grain structure of aluminum. Aluminum expands when it is heated, and as it cools, you hear the cubes sliding back into place. That is what is making the popping sounds.

 

The engine parts will expand as they warm up, then contract as they cool down, you have nothing to worry about.