2016 Ford transit connect engine knocking

High speed knocking is usually a blown piston rod inside the engine, which often damages other parts in line like the cylinder block where it needs to be re-honed on a CNC machine (or it will burn oil, even with new piston seals), but the top end often survives where the GDI or lifters are installed unless it's really bad or run like that for hundreds of hours.
Note: This is not as much of a concern on the diesel transit. While diesel glowplugs aren't as prone to damage since it takes more to kill them, it can still happen.

The problem is this issue almost always occurs due to poor maintenance somewhere along the line. Since the van has 54k miles, do not be surprised if they try and pin it on you. As a countermeasure, you can bring your maintenance records with you to the dealer if it’s under warranty just in case! Hopefully it’s a known flaw with the van so you can use it as leverage.

You’re going to need to rebuild or replace the engine unless it can be repaired - it’s usually too far gone once you hear rod knock. You’ll need to see which engine you have as there are 3 engines here:

• 3.5L (Gas, EcoBoost turbo)
• 3.7L (Gas, EcoBoost turbo)
• 2.2L i5 (diesel, totally different from the gas engines)

If you are not sure, there should be a sticker under the hood with the engine code and displacement to make it easy to find out which one you need, or in the door jam. This may also total it out since this is 5 years old and depreciation may make it cheaper to find a low mileage example of the same van.