Martyn
Supporting Sponsor, Overland Certified OC0018
With 250k on my 7.3 I wasn’t surprised when I started hearing some knocking from the engine. At first I thought it was time to replace the injectors but something told me to investigate further. As it turned out a good choice as performing that work would not have solved the problem.
After analyzing the problem I found a trend, it didn’t happen when the engine was cold, the knocking was intermittent, not rhythmical, and I had a higher than usual idle speed.
Luck was on my side when I did a Google search and the first link I clicked on described my symptoms exactly “Cackling or Knocking Noise” due to low fuel pressure.
Operating fuel pressure for a 7.3 should be 60-65 psi and mine was 30-45psi time for a new electric fuel pump. Further reading about the importance of fuel pressure also indicated that it might be time for a new fuel pressure regulator as well.
With both parts replaced my 7.3 is running smoothly again.
After analyzing the problem I found a trend, it didn’t happen when the engine was cold, the knocking was intermittent, not rhythmical, and I had a higher than usual idle speed.
Luck was on my side when I did a Google search and the first link I clicked on described my symptoms exactly “Cackling or Knocking Noise” due to low fuel pressure.
Operating fuel pressure for a 7.3 should be 60-65 psi and mine was 30-45psi time for a new electric fuel pump. Further reading about the importance of fuel pressure also indicated that it might be time for a new fuel pressure regulator as well.
With both parts replaced my 7.3 is running smoothly again.