2002 cylinder 7 misfire and overheat | Ford Thunderbird club group 1955-2005 T-Bird models
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2002 cylinder 7 misfire and overheat

  • Thread starter Thread starter nipperdon
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nipperdon

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Thunderbird Year
2002
When driving, emission light came on. Took to auto zone and had codes read. Indicated cylinder 7 misfire. Drove normally, no issues. When I got home, reserve coolant tank boiled over. Oil looks ok. Any thoughts or information on this issue? Car starts normally, but afraid to drive without resolving the issue. Thanks Reader code is P0307

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It is common to have the COP's (coil over plugs) fail. I think this is mostly with original COP's. Check this site for a link to a new set. I bought a set thru this page when I bought my 2003. A few years later I installed 8 new ones, but only 4 that I removed were originals. You can watch a you tube video as I did before starting the job. I'm not a mechanic, took me 4 hrs on day & 4 hrs the next. So I would check if you have ano originals, replace them all, or at lease replace #7. Good inexpensive way to start. This worked for me.
 
This doesn't cause the car to overheat from my experience. The concern here is the combination of a misfire AND overheating.
Was interesting that the temperature gauge read normal (in the middle of the gauge as always) and didn't indicate any issues whatsoever. Car ran normally after checking the code at auto zone.
 
Was interesting that the temperature gauge read normal (in the middle of the gauge as always) and didn't indicate any issues whatsoever. Car ran normally after checking the code at auto zone.
Not surprising. The dashboard indicator is designed to look like a 'gauge' but it's really only a readout indicator from the PCM. Like a glorified idiot light? As you go from cold to operating temperature, the PCM gradually moves the 'gauge' from cold to the midpoint, but then continues to keep the 'gauge' at midpoint while the actual coolant temperature varies, as long as the true temperature from the coolant sensor stays somewhere within an acceptable bracket. If memory serves, that's about a 30+ degree swing. It's only once the temps have already risen above an acceptable normal that the PCM will start to move the 'gauge' above the midpoint. Which accounts for the sorry fact that the 'gauge' doesn't give you much warning.

Sounds like you've had a hairline crack that's been allowing air into the cooling system and finally compromised it enough to trigger your experience. Verrry common with the cooling system in these cars ... odds are that you're due for a complete replacement of the 'plastic' cooling system parts, including lower hose, upper hose, and the various parts at the top-front of the engine block, one of which is a bear to replace. Unfortunately, and except for the degas bottle, Ford seems to have discontinued the OEM parts.

When driving, emission light came on. Took to auto zone and had codes read. Indicated cylinder 7 misfire. Drove normally, no issues. When I got home, reserve coolant tank boiled over. Oil looks ok. Any thoughts or information on this issue? Car starts normally, but afraid to drive without resolving the issue. Thanks Reader code is P0307
Your code + 'emission light' experience sounds a little more complicated than the 'usual' aging-coils (COP) issue. Usually the coils just get progressively weaker and start to stumble under load. But since you've received a code for cylinder 7, it might be worthwhile to pull the inspection cover and see if there's any oil in the spark plug well. It's not uncommon with this engine design for the o-rings to leak at the plug wells, leading to oil around the plug and COP, which will kill the coil is short order.
 
the 'plastic' cooling system parts
The "Plastic" part was made 24 years ago. How long is it supposed to last? SMH You realize that any metal alloy wouldn't last that long, right? It's so tiring to hear people making comments about it. Makes zero sense. 2002 Jeeps came with "Plastic Radiators" that lasted for 22+ years. Ignorant people would replace them with Aluminum radiators that last 5 years. SMH. The part is old, under pressure, 210F heat, cold etc. It is miraculously resilient! PS The same Jeep has cooling system metal parts where the thermostat is located that are getting pitting in them.
 
Update on situation: Replaced spark plugs and coils, motor running fine. Discovered that the heating problem is due to the cooling fan not working. I understand the 2002 has a unique cooling fan setup only used for one year. Is there a conversation kit available to switch to electric? I have been told the 2003 to 2005 have an electric cooling fan. Thanks Don
 
Is there a conversation kit available to switch to electric? I have been told the 2003 to 2005 have an electric cooling fan. Thanks Don
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