I just got my 2003 discovery and after a week engine codes of misfiring, changed the plugs then, The Cat went, Then this wonderful sound.
Engine Knocking knock - YouTube

 

WOW is all I got to say!
Sounds..............................well.......... ........................like it's got a clunk not a tick!



From what I heard, this is pretty much done. Sorry........my opinion anyways.

 

If you dont have it add towing coverage to your auto policy, then drive it until it lets loose.
Have several tow companies stored in your phone.
If you want it to last a little longer add 80w-90 gear lube to the crank case.
But she is done for.
That rod knock is so bad the only cure is a total rebuild or a different engine.
How long has the oil light been coming on?

 

the oil light never came on, I got the truck at 80,000 at 82,000 the sound came on. Its been siting for 3 weeks as i look for a new engine or find a place to rebuild the engine in Atlanta.

 

Or does oil light come on at all when engine first cranks? Wire might be off the sensor. That would explain not seeing an oil light. Spike is right, if one rod is gone, others are not far behind, somehow this engine has been oil starved. We have forum members who have done rebuilds, some have worked the crank bearings without removing the engine.

 

The plugs were changed and oil changed at 80,000. i understand it's a done deal until rebuilt of replaced.

 

Well, one source in Atlanta is usually Pull-A-Part, but their current inventory is like a dozen D1s. You might want to register with them for an email alert if one comes on the yards (3 in Atlanta).

 

Who changed the oil?
What oil did they use?
You might beable to pin this on them.

 

Precision Tune Auto Care, 10w30 not sure what brand. Had 8 codes when i went in
P0302, X2
P0300
P0304, x2
P0306, x2
P1300

this was on the receipt

 

Ok, the oil they used, though not the preferred oil did not cause this.
Had they used 5w-20 you might have a case.
Do you have any warranty with the truck?