e99 with 291K on 7.3L

Idle sound horrible. Sounds like a really loud dieseling or I dumped ball bearings in the topside of the engine. When I start to give it a little pedal, the sound drops to normal. No power issue I can tell.

This just started this morning. It happened when cold and then again when hot as well. While driving, and at temp, when I let off the fuel to coast or stopped at a light, the loud idle would cycle on/ off like someone was throwing a switch. When I got home and popped the hood, I could not tell where the sound was coming from.

Any ideas as to the source? or where I should start looking?

Thank you in advance.

 

Have you done injectors? Reason being is that once splitshots start getting old the cackle becomes more noisier and almost sounds like a rod knock.

 

I have not done injectors. Would they crash so dramatically in one day?

 

Sounds like it is time for the hutch mod if you have not done it yet. Or your fuel pump is not maintaining pressure and is introducing air into the system. If it sounds like a rod knock on the d/s rear that is more than likely what's happening. I get the same knock if I push the go fast pedal to low for to long. Just a thought.

 

Do you have a way to monitor ICP pressure, ICP voltage and IPR duty cycle? Have you ever heard a KOER test being run?

 

I do not know what the KOER test is.

 

When I had a banging idle with really warm oil, and it would disappear with throttle - it was a couple of injectors. This happened to my injectors in one day:


Oil way past change time, air in fuel, or improper maintenance schedule on the fuel filter can lead to messes like this. Our injectors are not fussy about what they eat - just how it's dished up. The biggies in diesels are clean air, clean fuel, clean oil... and plenty of 'em.