Sudden rough engine at all speeds
#1
Sudden rough engine at all speeds
Hi all, I am hoping someone can tell me the most likely failure mode for my '06 Grand Marquis (160K). I was traveling at speed (55-60) everything seeming fine when suddenly, with no prior symptoms, the engine began to run rough. Within less than a mile, before I could pull over, the check engine light came on. I pulled into a parking lot, pulled out my smart phone and launched my OBDII app (ain't technology great). Trouble code P0308 - cylinder 8 misfire.
With this vehicle, what is the most likely cause? Spark plug, spark plug wire, coil pack (if it has one)? In the three years I have had this beauty I have never had a lick of trouble. Other than changing fluids I haven't had to do anything under the hood.
Any assistance greatly appreciated.
Roy
With this vehicle, what is the most likely cause? Spark plug, spark plug wire, coil pack (if it has one)? In the three years I have had this beauty I have never had a lick of trouble. Other than changing fluids I haven't had to do anything under the hood.
Any assistance greatly appreciated.
Roy
#2
Your Grand Marquis has a "coil-on-plug" type ignition, which means there are no ignition wires to fail.
I misfire would be from a bad spark plug or a bad coil on the #8 cylinder.
Looking from the front toward the firewall, #8 is on the right (driver's side), closest to the firewall.
I don't know how old the plugs are, but I would replace them all so you know EXACTLY what is in your engine and how long the plugs will last.
I use and recommend the BOSCH #9606, which is a fine-wire, Double-Iridium design that has a life span of 100,000 miles +
I got mine at RockAuto -- best price !!
I misfire would be from a bad spark plug or a bad coil on the #8 cylinder.
Looking from the front toward the firewall, #8 is on the right (driver's side), closest to the firewall.
I don't know how old the plugs are, but I would replace them all so you know EXACTLY what is in your engine and how long the plugs will last.
I use and recommend the BOSCH #9606, which is a fine-wire, Double-Iridium design that has a life span of 100,000 miles +
I got mine at RockAuto -- best price !!
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