I have a 2004 Excursion with the 6.0, 195XXX Miles, bone stock except for a coolant filter. I use 5w-40 Rotella, gets serviced every 5k, fuel every 10k. We’ve only had the truck for a little over a year. Only issue I had up until today was an oil leak from somewhere on the front/top of the engine that leaked a quart every 5-6 weeks. Hadn’t had it fixed or fixed it myself due to vehicle/time constraints, it was scheduled to go in early April for that. Ok, down to what my wife said happened today (I’m a truck driver and am currently out of state so I have no firsthand access to the truck currently). She said she was headed into town, doing 55-60, all of a sudden it was like she blew a tire in the sense that the “ride got really bumpy, like I was going down a county road faster than 15 mph”. I was tied up so she tried calling me for a half hour, she left it idling this whole time due to fears “of it not restarting and I wanted you to hear it”. If I can I will attach a video that she sent over of the sound it was making. She shut if off and then had it towed back to the ranch. She said the tow driver tried to restart it to move it out of the middle of our driveway and “it started but the noise was 10X worse, it ran for about 8 seconds and then shut off”. I’ve heard 4 different theories so far from shops local to me about what it COULD be, so I figured I might come on here and see if anyone has had a same or similar problem and what they ended up finding. We love our beast so fixing it is what we’re after, but beings we don’t know exact cause I’m just not sure if this is something I can undertake myself or if it’s something I should just have done.

Knocking is usually rod bearings on the way out but these engines have pretty robust bottom ends so not very frequent they spin a rod bearing but it can happen. Best to post the audio file so people can hear. My truck has a knock that is pretty noticeable when cold but the experienced PSD mechanic diagnosed it as a fuel knock. Been fine and hasnt got worse in 25k miles so he must have been right.

You Tube

No smoke at all

Thank you too many toys

Managed to secure a load to the house today so I’m gonna have eyes n ears on it Tuesday. I’ll get it plugged in then and post my findings.

When you get to it, video jumping the starter with the starter jumper connector at the passenger fender to see if one cylinder has a loss of compression.

be able to tell that just thru a video of it cranking or will I need to actually set it up for a compression test?