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Ford/engine light on for misfire cylincer #5


My 2002 Ford Taurus, 6 cyl, 82,000, well maintained.
The other day with cruise control on the transmission dropped down to pick up speed to 70mph. I believe it dropped all the way down to first gear because the RPM's raced up to 4500.  The car immediately began to run rough and the engine light came on.  This event lasted about 15 seconds.  I pulled right over.  After letting the car sit, I resumed my travels, stayed it 50mph and the car drove okay except the engine light was on.  I took it to a mechanic, engine code said misfire cylinder 2 and 5.  He changed out the spark plugs and wires (with recommended brand), however engine light came back on in 24 hours. Engine code reads misfire cylinder #5. Mechanic did a compression test.  Found 170 in 5 of the cylinders, 110 in cylinder #5.  He put in a new spark plug for that cylinder, said I'd gotten a bad one. Engine light changes from being on steady and blinking. Mechanic wonders if it's a bad ring in that cylinder.  A second opinion mechanic says maybe some carbon and junk broke loose when I had that highway incident.  Wants to hook the engine up to a machine that flushes engine cleaner throughout.  I'd like to hear your thoughts.  Thank you

Hi , the engine flush, isn't a bad idea if he is going to do a carbon cleaning. It is done by running cleaner through the intake manifols and the idea is to remove and deposits on the back of the valves which if you have one sticking open, this should fix it. Where are you located ? State ? Has he replaced the cool ? Cylinders 2 and 5 fire at the same time so that maybe something he wants to look in to. This motor was not known for ring concerns so I'd be looking at either a bad coil . Bad injector or do a thorough cleansing of the valves


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brian howard


I can answer most question from drive ability to electrical, electronics and almost all check engine light concerns from 2000-2013 vehicles


I am a Ford Certified Master technician. I specialize in drive ability concerns, but can help with most concerns from steering to suspension and climate control relating to Ford And Lincoln/Mercury products from model year 2000 to current

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