Help: Catastrophic Engine Failure 5.7L V8

Again even if the knock sensor was disconnected/chewed/etc it will go to a default value that would likely be in a spark timing table that is a safe value. It wouldn't go to 50+ degrees of timing. And even then if it did, that wouldn't cause the engine to self destruct on start up.

I've done engine teardowns for decades and in my current occupation I do machinery failure analysis and I see no possible way this is an engine controls problem.

Not on start up...no way.

Engines in general will get holes in them from loose rotating assembly parts. Crankshafts, connecting rods, pistons. These are caused by gross overloads of their material properties (stress, strain, thermal, ductility).These conditions prevail when there are large amounts of liquids or non-malleable foreign material ingested in engine. It can also happen with lack of lubrication to crank or rods. And excess engine speed can also cause the overload conditions. On overhead cam engines a timing chain failure (stretch or break) can cause this with piston to valve contact.

In rare situations, large magnitudes of high frequency, where system is operating at (the forcing function) or on mechanical natural frequency, vibration can cause cracking (older 5.0 Ford engines cracking in mid block along oil galley).

Looking at the pictures, the intake ports look fairly uniform. I don't see any signs of a few ports being exposed to a wash of liquids. Perhaps a really bad headgasket leak. These are rare and usually have plenty of other symptoms that are not detailed. Overheating, coffee looking oil, strange bubbles in radiator...

Lack of lubrication will be found in rod bearing and main bearings. In overhead cam engines the cam bearings are usually show signs of low flow first. You will also get a host of other engine codes and a tell tale is usually cam timing related codes.

Check timing chain stretch for one side vs the other. 5.7 does not have a history of stretched chains. Broken crankshaft key way will cause cam timing to be way off and lead to same issue. Also check crank sprocket for signs of distress.

Engine speed excursions will set a code usually. But also these engines have a rev limiter so this is doubtful.

That leaves foreign object damage. A good teardown will uncover these things.

Your best bet at this point to get back on the road and understand this failure is:

Get a reman engine. The one in the truck now is not repairable in any circumstance.
Teardown old engine at a shop. I can't imagine a shop not wanting to do a teardown on a 5.7. Or procure engine hoist and stand and do it yourself.

 

I don’t know how far you have to tear down an engine to replace a knock sensor, but based on your diagnosis could they have forgotten to put oil back in before starting it? Would that cause the holes or would it just seize the engine? I did see how you seemed to think it was a foreign object.

 

only if they changed the oil in the process.

And also going off of the description, this happened immediately on start up.

An engine with zero oil, but at least a film on bearings, would run about 5 minutes and start to seize up.

It would only window the block if the bearing spun and engine continued to run.

Amusing anecdote.

I've seen a chevy 350 in an old nova run 20 minutes with no oil.

At the garage I was working at, at the time, I had to move a beater nova out of the way. There were multiple techs at the garage. I was first there in the morning. Hood was closed, keys were in car. No notes. I had no idea that a new tech stayed late and started an oil change on the car.

I fired the car up. backed it out of garage. It took about 6-7 min of manuevering out of a tight spot in a garage.

For some reason I left the car run while I moved another car out.

I started working on my car. I realized I left the nova running. I go out to check and I'd swear it was at least 20 minutes since I started it.

It was smoking, knocking, but it still ran...

I shut it off. It wouldn't restart. I opened hood and saw smoke coming from dipstick tube. Pulled dipstick and found no oil.

I found out later the other guy wanted to do an overnight drain on the car. But left no notes in it. Closed hood and left keys in car.

free 350 for that customer...

 

*Plot Thickens*