Derf00

What year is the car? I know first gen coyote engines in the 2011/2012 had this issue with the #8 cylinder which mainly reared it's head after a tune which pushed the timing and a/f table. The failure was attributed to many potential sources including insufficient cooling to that part of the engine, a bore that was out-of-round, or valves that collapsed. Just do a google search for Coyote #8 cylinder failure.

Tuned engines tend to lean out the mixture so they run hotter. It was such an issue that in order for Ford to cover their butts, they released a TSB about it. While not explicit to calling out #8, that was where most of the failures were so I consider it implied within the Ford circle.

If a motor is found to be tuned with a failure, your warranty on the engine was automatically voided. If the tune was not found but evidence of the PCM being wiped (yes it keeps track of that), and there was still reasonable suspicion the motor was previously tuned, they could still void your warranty.

https://latemodel.cachefly.net/downl...sb11-07-07.pdf

While this is not really new (mods can void warranties on those parts you repalced), what is new is the fact they actually released a TSB to begin with. In the past, most dealers would work with owners, this is the first time, it was explicitly written to be black and white.

socal57chevy

TSB...
AERA is the shiznit

KillverCity

The car is a 2017. No tune done on the car. Nothing aftermarket. It's exactly as it was sold to me with the addition of an air freshener.

They called me yesterday to inform me they are sending the cylinder head off to a machine shop.

12 days in the shop so far on this round.

KillverCity

Dealership called and said the cylinder head tested fine. Now they wait to hear from Ford again to see what to try next.

darkmach1

I blame it on the air freshener.

socal57chevy

Good grief Charlie Brown. That's ridiculous.

KillverCity

They just called and said they are replacing the entire motor. Manager is calling me in the morning.

So bummed.

KillverCity

So Ford replaced the motor. Scuffed up the wheels while they had it. Fortunately they repaired that damage.

Threw another check engine light about 5 days later. Tried to take it back to dealership, they said I would need to purchase a premium care package in order to have a rental car.

So now I have a check engine light on my second motor in my 2017 Mustang GT.

Ford is refusing a replacement vehicle. I am so thrilled with this experience.

Derf00

Check the lemon law for California page 7. I think your car more than qualifies for it.

http://www.dca.ca.gov/acp/pdf_files/englemn.pdf

Sayre

Please keep updating. Interested in how this ends up playing out.