milk-truck

HELP!!!! Brought my 2010 f 150,00 5.4 to dealer for no power on dash. They found the issue. I asked them to check a vibration in tranny (very random slight shaking ). They could not find anything. I asked for a further look. They suggested i change my plugs 150,000 Miles. They stripped my plug had to fix it. Then i got a call that i needed a new motor. I have a hole in piston number 6. They claim the stripped plug was cylinder 7. They claim that my truck was miss firing on cylinder 6 which caused the piston to get weak and when they changed the plug the spark burned the carbon build up on the piston and caused a hole in the piston..... My truck never had any motor issues or never had a check engine light. They claim a miss fire would not trigger a check engine light. They are not owning up to blowing my motor...... Anyone heard of this happening??? I'm not stupid and I know they blew my motor and need legal advice!!!

CollinM

Carbon build up can lead to a hot spot leading to dual ignition. This can lead to detonation

1917-1911M

That is a tough one but the assessment doesn't sound correct. You do have a lot of miles on the engine but I was thinking all of these engines have knock sensors that retard the timing should any pre ignition occur. You would have noticed the roughness of a missfire and a cut in power with retarded timing. I've never heard of dual ignition. Pre ignition...yes. That is when the fuel/air mixture detonates from too lean a mixture, hot glowing carbon or fuel with too low an octane. The problem is the mixture burns/expands while the piston is still on the way up, not ready to be forced down. Engines routinely detonate the mixture before the pistol reach top dead center and is ready for the downward power stroke. The reason is there is a momentary delay in ignition and burn. The fast the engine is running, the sooner the mixture must be ignited. This is very carefully controlled by your computer and knock sensors. Premium gas, higher octane is not a better fuel in and of itself....it is simply harder to burn which is why it is used in high performance engines, turbo charged, blown or high compression. All of which heat up the mixture and generate greater heat over a conventional low compression engine.

The rear cylinders and all associated parts do run hotter. Number 6 is on the opposite side of #7. There will be one way to check for sure. I'd get their explanation in writing, clear and concise. They may be correct but when you/they pull that head it will be obvious if the hole was slowly burned or if something metallic like a broken plug, dropped socket, etc. caused the problem. If you see evidence of something mechanical banging around and leaving fresh indentations....it wasn't pre ignition or a hot spot that caused it. My 2 cents. M1911

meb

number 6 is on the opposite side of number 7??? Feel this is incorrect. Ford goes

8 4
7 3
6 2
5 1

or 1 starts on the opposite side but the basic patter in correct

1917-1911M

I will have to check that. I've never seen cylinders counted that way. You could be right. hwy61

rbrais

I don't see how changing the plugs (even screwing up royally) can lead to a hole in your piston.

I'm willing to bet the vibration you have been feeling was the missfire/piston damage. Missfires don't always throw a code. I drove around for a week with a bad missfire, hoping it would let me know which COP was bad. Nothing; no code. Then it cleared up on its own.

1917-1911M

Thanks meb. Learn something every day. GM and Chrysler don't count this way...at least they didn't back in the day. It took some looking around to find the correct layout. Some say this, some say that. Apparently:

Front of engine

5..................1
6..................2
7..................3
8..................4

I've always assumed all V8s were the same, e.g.

2..................1
4..................3
6..................5
8..................7

M1911

papa tiger

It is possible they knocked parts of the plug into the cylinder than proceded to run the motor banging a hole in a piston.

meb

Sorry to hear about the whole thing. What they want for a new engine or possibly a doner since that was a fairly popular motor?

zeniceguy

The plugs are 1-4 right front of truck back, 5-8 left front of truck back.

Get a look with a bore a scope. Sounds like when the hole was drilled and heli coiled the piston was not set to bdc. If it isn't done y,our drill bit will drill into the top of piston.

Also a misfire is seen by the pcm. If it is a and missfire. The engine light wi..ll flash. It will also set a code for a miss fire on cyl 6 a P0306.