Here's a quick back story. My 2003 5.4 s-crew lariat w/ 197,xxx miles had a terrible miss & was very sluggish to the point that it would barely run last Wednesday on my way home. I took it to the local shop that I have been using for the last 3 years, they replaced the intake manifold gasket, valve cover gaskets, all 8 plugs & 1 coil. They noted that all 8 coils had been soaked w/ coolant & oil, but only 1 was missing. Had to take it back in Saturday for misfiring again (not as bad, but noticeable) & they replaced 2 more coils. Last night it started missing again just like Saturday.
My question is this. Is what they told me about the coils being soaked plausible? Should I go ahead & replace the remaining 5 coils, or is there something else that could be the cause of the misfire that I should look into first?
Any help/opinions are appreciated.
Thanks in advance

 

Should of replaced them all to begin with.. was coolant coming from a bad intake manifold ? just replaced on myself...

 

That was my understanding.
The only reason that we didn't replace them all at that time was the cost. After some research on my part, I now know that I can replace them all at a much less cost. My plan, currently, is to replace the last 5 myself this weekend. I just wasn't sure that the leak could or would actually cause that. Or if it is worth the effort to attempt checking the last 5 individually.
Why would they fail days apart if the cause was the same for all?

 

with a bad coolant leak...ie all over the coils, I would of replaced the plugs/COP's and the boots and springs...if the boots are worn and no dielectric grease applied to each end they can allow moisture into the spring which carries your spark from the COP to the plug...if it were to get wet inside the boot it would cause a mis-fire or even short out a COP. Just my thought..

 

Thank you for that explanation. That helps me understand the situation. I feel like I should be safe in replacing the remaining coils & that should solve my problems.
Are the "Accel" coils or "MSD" brands decent, or should I stick with Motorcraft? Is it necessary for all 8 to be the same brand, or will I be okay replacing the 5 & leaving the 3 that the shop already changed?

 

Motorcraft first choice...Accel second choice...I would do the boots and springs with the COP swap...what brand did they use for the ones you had replaced ?

 

I'm not sure. I have to call them to find out & to find out what #'s they replaced, even though I'm sure I'll be able to tell from looking at them.
I thought, from looking at them, the boots, springs & coils all came together, not "sold separately".

http://www.summitracing.com/parts/ac...FRCNaQod8JIDJw

Is this not what I'm looking for?

 

Those do...some do not. Those are for the 5.4 3 valve...I believe your motor is a 2 Valve..

 

Thank you. I'm sure this is a stupid question, but how do I know if I have the 2 or 3 valve motor?

 

VIN# If the 8th character in the VIN is "L" it's 2v, if it's "5" it's 3v.