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Cylinder 2 Misfire - 2010 SHO

Started by GUF, April 04, 2019, 08:19:34 AM

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GUF

I have a 2010 Ford Taurus Sho that the number 2 cylinder misfires under boost.  We have replaced:

PCV breather assembly, PCV valve and heater, all six spark plugs, Cylinder 2 twice, all six coils, all six injectors.

Cylinder two is showing 12 to 15% less compression than the rest, vehicle does not misfire at idle but misfires under boost on cylinder2.

Any ideas where I should look next?

SHOdded

Welcome!  I would scope the back of the intake valves to see if there is perhaps a noticeable difference in carbon buildup there.  If there is, that is possibly a culprit.

If not, I would suspect the beginning of compromised piston rings.  What engine oil have you been using (brand, weight) and for how long (miles/engine hours)?  You may want to consider using Auto-Rx or similar treatment to see if compression can be restored.  Fingers crossed.
2007 Ford Edge SEL, Powerstop F/R Brake Kit, TXT LED 6000K Lo & Hi Beams, W16W LED Reverse Bulbs, 3BSpec 2.5w Map Lights, 5W Cree rear dome lights, 5W Cree cargo light, DTBL LED Taillights

If tuned:  Take note of the strategy code as you return to stock (including 3 bar MAP to 2 bar MAP) -> take car in & get it serviced -> check strategy code when you get car back -> have tuner update your tune if the strategy code has changed -> reload tune -> ENJOY!