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What is your question?
ok.... this has me puzzled, there is a missfire in the number six cyl. replaced back pressure senser was told it was bad. replaced plug, was told when I bought it that it had new plugs wires, coil pack, and plugs. Could the egr valve cause a missfire in one cyl? Or am I needing to replace coil pack?? missfires worse when at an idle for a few min.
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The 3.0L V6 DOHC 24 valve engine has a coil on plug ignition - meaning each plug has it's own coil. Since you are speaking of coil pack and wires -- do you have the 3.0L 12V OHV V6 instead? Makes a difference in this discussion. I'm going to assume you have the 3.0L 12V OHV engine. If you have a misfire, and you have replaced the plug, wires, coil pack, etc etc... You have not addressed base engine and valve train. Perform a compression check. I'm betting cylinder #6 is lower than the rest. Then, perform a leak down test to see if you have an intake or exhaust valve leaking. OR, you could have a base engine problem in that cylinder which will cause a misfire. For sure though - an EGR valve will NOT cause this problem... Good luck!
Ok the car runs great while driving, will a bad valve cause the car to smoke, orrun bad, get really bad gas mileage, same thing with bad rings??
It says it is a 3.0L V6 DOHC 24 valve engine, is 2002 difference from 2003 this was produced at the end of the year and I know some things were changed such as some sensers. it has one long rectangler shaped coil... could a vacume leak on the plinum cause a low rpm missfire? I have done a compression check this cyl it is close to 90. Oh and what is a leak down test? same thing as a smoke test??
Goodness, consider me in error. Indeed you do have the single coil pack. I apologize for the confusion; mixed it up with another 3.0L DOHC 24V V6 in another Ford vehicle. A vacuum leak will not cause your misfire. You have a HUGE clue with the compression test showing 90 PSI. That is nearly half of what it should be. I would think you should be somewhere between 150-180 PSI per cylinder. Did you check any of the other cylinders? A leak down test is when you insert a leakage detector into the spark plug hole, bring the piston up to dead center on the compression stroke, and admit compressed air. Once the combustion chamber is pressurized, a special gauge included in the kit will read the percentage of leakage. Leakage exceeding 20 percent is excessive. While the air pressure is retained in the cylinder, listen for the hiss of escaping air. A leak at the intake valve will be heard in the throttle body. A leak at the exhaust valve can be heard at the tail pipe. Leakage past the piston rings will be audible at the Positive Crankcase Ventilation (PCV) connection. If air is passing through a blown head gasket to an adjacent cylinder, the noise will be evident at the spark plug hole of the cylinder into which the air is leaking. Cracks in the cylinder block or gasket leakage into the cooling system may be detected by a stream of bubbles in the radiator. Good luck; I think you're on to something.