Misfire cylinders three and four, head gasket replacement

2004 FORD F-150
245,000 MILES • 4.6L • V8 • 4WD • AUTOMATIC
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BANSHEE JOHN
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Number three and four cylinders misfiring. Spark plugs have fouling but not from oil. Can I replace just that side head gasket or should I replace both?
Sep 2, 2018 at 12:11 PM
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ASEMASTER6371
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Good afternoon.

It is always suggested to replace the pair.

How did you determine you have a failed head gasket? Did you do a compression test?

Roy
Sep 2, 2018 at 1:38 PM
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BANSHEE JOHN
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My mechanic made that determination. He thinks it started with the o2 sensor in the converter went causing it to call for more fuel. Anyway new converter passenger side, two new o2 sensors, coils, plugs. Three and four fouling, plugs have a liquid on them not oil. I got almost 250,00 miles on the truck. I am going to fix it and sell it.
Sep 2, 2018 at 4:49 PM
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BANSHEE JOHN
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Thanks for the information. Should I put new head bolts too?
Sep 2, 2018 at 4:51 PM
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ASEMASTER6371
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Yes, that is a good idea.

You are welcome.

Glad to help.

Roy
Sep 2, 2018 at 5:05 PM