Cylinder misfires

[crrushing]

Guys I just took the car (after the ck engine light started blinking) to autozone for a diagnostic ck and it came back with all cylinders misfiring. Its an 06 and i have 114K miles on the car, I am sure it is time to change the plugs, but would you guys do anything w/ any of the coils? Should I just change the plugs and that's it? I know it is fairly difficult to get to the back plugs, so If you guys have any other suggestions, i sure would appreciate them. Do you think it could be something other than the plugs/coils?

Thanks

[05DCLB]

Clear it and see what codes return, I would suspect a coil before a s-plug.

[blkavalon]

its more like coils

[inov8]

While the probability of all 6 apark coils having failed in 144K miles is admittedly not zero, it is pretty darned close to zero. 114K miles at an average speed of 30mph is ~3800 of operation. Modern spark coils are stress tested to ensure a failure rate of less than 1 per 10,000 hours of continuous operation.

I would start with the least expensive parts . . . the spark plugs. After >100K miles, none of the gaps are likely still within specification.

Has anyone cleaned the sngine recently? It's not unusual for water to seep into the spark plug wells and cause misfires.

[crrushing]

No, no one has cleaned the engine recently. 1st I guess I will get the codes cleared and see what comes up before I do anything. What would cause all the plugs to fail at once?

Thanks for the info.

[inov8]

The spark plugs haven't "failed" in the classic sense. They are still igniting the air-fuel mixture most of the time. An occasional misfire may be just a warning that they are approaching the end of their service life. If they had "failed", the engine would not run at all.

Each plug fires (arcs across its gap) once for two engine revolutions. And each arc, similar to electrical discharge milling, etches away a little of the electrode material. If your average engine RPM is 1500, each plug has fired about 171 million times over 114K miles. Try serving a tennis ball 171 million times and see how much of your elbow joint is left.

As a test, you might try try first just replacing the 3 plugs that are easy to access, on the side of the engine nearest front of the car. Then go back to Autozone and see of some cylinders no longer report misfires. Then you can replace the difficult back 3 (buried under the intake manufold) with confidence that your problem will be solved.

[crrushing]

I really did not mean to say failed, and I also meant to say coils rather than plugs in the previous post.

Thanks for the info. That makes sense to go ahead and change the ones easiest to get to.

Thanks again,