Can't locate the engine serial. I have a 2004 FX4 f150 that came down with an awful engine knock until it finally took a nose dive at about 120k miles. A mechanic I know ordered a factory rebuilt from Ford, (apparently through a 3rd party) and installed it claiming it has a 3 year warranty on it and that ford redesigned it knowing it had this "known issue." Now it's 5000 miles later.....same exact knock. To the point where it will soon again fail.

The mechanic diagnosed it "by ear" as the same previous issue and said he would follow up on the warranty. But now he claims he lost the warranty card and his supplier is not stepping up to replace it. I finally threatened legal action and months later he said he would have to tear it down and take pictures but hasn't committed to a warranty job.

I'm concerned that he may have just painted the old block and did his own rebuild on the original engine. I contacted a dealer with my VIN to see if it would show up on their radar but they said they wouldn't be able to tell. I want to check the serial to see if it's the original block and go from there.