I have to agree with hope it is the fan hitting the shroud. Otherwise, it sounds like a bad case of a rod knocking. Going by how you say it gets better after running some, I'd go with the latter. That would be the oil reaching it helping it to sound better.
When was the last oil change?
You can maybe buy some time by making sure your oil is good, maybe a slightly heavier weight, and run it GENTLY AS POSSIBLE.
It probably won't leave you stranded when it fails completely, but you'll know when it is limping along.
I drove a 4.3 to, from and back to a garage about a mile or two away in an urban setting with 3 cracked pistons and head gasket. First was to confirm what I had thought, brought it back until an engine was located, then back to have it put in. It limped but it made it. I did the damage running high rpms in 4low playing around, not by any actual normal road use.
When was the last oil change?
You can maybe buy some time by making sure your oil is good, maybe a slightly heavier weight, and run it GENTLY AS POSSIBLE.
It probably won't leave you stranded when it fails completely, but you'll know when it is limping along.
I drove a 4.3 to, from and back to a garage about a mile or two away in an urban setting with 3 cracked pistons and head gasket. First was to confirm what I had thought, brought it back until an engine was located, then back to have it put in. It limped but it made it. I did the damage running high rpms in 4low playing around, not by any actual normal road use.
