Well since Ford finally denied the warranty claim on my engine I suppose now is a good time to come clean.

Long story short, I supercharged my car, got a dyno tune from a highly reputable tuner, daily drove the car for about 10k miles before it started misfiring and blowing smoke out of the catch can vent. Did a compression test, low compression on cyl. 8. Had an independent shop confirm my findings.

Decided to return the car to stock and take it to Ford just to see what they would say. Approved them taking the one head off to check the piston, rings, etc. Two days ago they called and said an engine replacement would be covered under warranty and I was free and clear. Today they called and said actually LOL nevermind Ford denied the claim due to a PCM flash. Drove over to the dealer turns out the engine is COMPLETELY torn down, front cover, timing chains, oil pain, both heads etc. removed. Now they want to charge me for the teardown after they said it was approved for warranty work.

I'm going to pick up the car tomorrow and trailer it home. If you were me would you:

1) Have the engine rebuilt by an independent shop (rods, pistons, machine work)
2) Look for a Gen 2 or Gen 3 used engine to drop in (don't know anything about this really)
3) Trade the car in broken (would love to get a 2018+ A10 but really don't want another car payment)

 

The #8 cyclinder failure is/was a know issue for the first gen 5.0. Ford even issued a tsb about tunes voiding warranties if there was an engine failure and a pcm flash was detected (like yours). Had to do with coolant routing or oil flow in the engine but a tune made the issue more prevelant. That being said there have been a few failures in just stock form too. You’ll find them on any one of the 3 Mustang forums.

Anyways, gen 2/3 don’t seem to have this issue.

 

dacampora, Derf00 is right about that #8 cylinder. During my travels at NMRA races, the rumor was that the #8 cylinder is "syamized" and is the week link in the chain. I immediately routed as many air tubes to the #8 cylinder and have 83,000 trouble free miles. I am also "old school" and leave the front hood cracked about one quarter inch. I figure looks don't cost as much as a engine rebuild. But back to your warranty problem. Under these circumstances, the first thing I would do is consult a reputable warranty attorney. They have a way of working things out with dealerships.