Don't agree with dealer diagnostic

[rummelma]

Good morning.

I have a 2005 Explorer 4.6 SOHC.

I know that every 7k - 9k my coil #3 (C) will go out and needs to be replaced. When the coil does go out, the air condition stops blowing cold air.

Well this last time I changed the coil due to missing, i broke the tail that connects to the coil. I also went from a Motorcraft to Accel coil. I went and got the new tail and a friend at the dealership installed it.

I noticed it was still missing. I had the codes rechecked at the local auto parts store and they said coil #3 and #4 were missing. I bought new Motorcraft coils from dealership and replaced both, along with new Motorcraft plugs. She ran like a champ.

3 days later as i am driving i feel the truck begin to miss again. As i exited the expressway and came to a stop, the truck began to shake bad. I pulled into the local auto parts store and had the codes checked. I was told the #3 , #4 and #5 coils were misfiring, and there was a misfire before a 1000 rpm.

My friend at the dealership advised that i go to dealer and have them do a diagnostic check. I took it in. The dealer said i have a dead cylinder, #5 , and i need to install a new engine for $7000.

The reason i don't agree is because if the cylinder was dead, wouldn't there be an awful knocking, or smoke? And also wouldn't the codes show something different than a misfiring coil?

Thanks for your time and assistance.

-Mark

 

[rocco123]

M

 

[rummelma]

i believe i was a 20

 

[rummelma]

yes confirmed. they said compressions was at a 20.

 

[swshawaii]

Safe to say the dealer's correct. Sorry, but you are in denial.

http://www.explorerforum.com/forums/showthread.php?t=204909

 

[rummelma]

ugh . . ok. . . . i found a place that will rebuild my engine for $3500. I will check them out

 

[rocco123]

S

 

[rummelma]

thanks. Begin i just spent $5500 on trans rebuild and struts for my wife's mazda van 2 weeks ago, and daughter getting braces, 3k, next week, now this on my truck . . . . . i will need to call for hair replacement . . . .

ha

 

[rocco123]

T

 

[rummelma]

thanks

 

[rummelma]

Update - a rebuilt engine is not needed. Turn out was a bent valve. A lifter got stuck and cause the valve to bend. I will be getting a valve job done, so only the head will need to be removed and machined.

 

[rocco123]

H

 

[rocco123]

d

A

 

[rummelma]

The mechanic scoped the piston. You could see were the valve was hitting the crown of the piston, but no damage.

I was using motorcraft coils. Where do i get those heli coils?

 

[rummelma]

because i do change out the #3 every 7 - 9k miles or so

 

[rocco123]

H

 

[lincolnshibuya]

Also, if u plan on keeping the truck I recommend getting heli coils for plugs if they dont already have them. My 02 does not and I spit #3 plug a couple years ago. Common issue with 4.6

I don't see this a common issue on 4.6 unless the threads were galled because of overtorquing the spark plugs. It's a very common issue with the expedition/navigator/f-150 that has the 5.0 triton v8, the thread depth for the plugs are too short and also bad spark plug design.

 

[Number4]

To use a Heli coil you first have to drill out the spark plug hole, then tap it to fit the coil which is inserted.
I'd agree that over torquing (ie. Using thread anti seize or no torque wrench) is probably the most likely cause for a stripped plug hole. The torque on the spark plugs isn't much. If you just torque by feel, you are probably over torquing. Same goes if you use anti seize.

 

[rocco123]

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