2000 Town Car Signature - cylinder 5 misfire - again

[lasmith]

About 6 months ago cylinder 5 began misfiring. Replaced coil pack and spark plug. Ran fine until today when skipping began and check engine light started flashing before going off, then staying on. Checked the codes and indeed cylinder 5 is misfiring again. Anyone have any ideas why this cylinder keeps failing?
Thanks

 

[JuanOrtiz219]

Im going through this same mess .. except mine is cylinder 6 i also get all kinds of codes. two good mechanics both state my ECM is the culpret i got to replace it. I pray its not that in your case. I changed all the spark plugs the coils the connectors had the Mas air flow checked the pressure in the cylinders everything checks out only thing left it could be is the ECM for me anyway

 

[dave42]

Be sure that your thermostat housing or intake crossover isn't leaking. I 'think' cylinder 5 is the one that is most likely to be affected by some coolant getting into the well.

 

[lasmith]

Im going through this same mess .. except mine is cylinder 6 i also get all kinds of codes. two good mechanics both state my ECM is the culpret i got to replace it. I pray its not that in your case. I changed all the spark plugs the coils the connectors had the Mas air flow checked the pressure in the cylinders everything checks out only thing left it could be is the ECM for me anyway

It turns out that the problem wasn't cylinder 5 even though the code was for number 5. Ended up replacing all the plugs which did the trick for me. I hope you will be able to repair yours without too much trouble.

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[lasmith]

Be sure that your thermostat housing or intake crossover isn't leaking. I 'think' cylinder 5 is the one that is most likely to be affected by some coolant getting into the well.

That's not a bad idea. Thanks

 

[Norms1stTC]

Only Motorcraft coils and plugs for these Panthers , anything else and you're throwing your money away.

 

[lasmith]

Only Motorcraft coils and plugs for these Panthers , anything else and you're throwing your money away.

No doubt. They are fussy that way.

 

[G-19877]

That's not a bad idea. Thanks

My #5 misfire was from the thermostat housing leaking antifreeze into the spark plug hole/area. Thanks for the info!

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[Norms1stTC]

My #5 misfire was from the thermostat housing leaking antifreeze into the spark plug hole/area. Thanks for the info!

Yep, it usually is that very culprit....