Misfire diagnosis

[bojans]

2006 Explorer 4.6 V8, ~ 90k miles

Code P306 - cylinder 6 misfire. Swapped coils with the # 1 cylinder and still have a P306. Next step to replace the injector on number 6? Spark plugs were replaced ~ 20k miles ago...

Thanks for the help.

 

[A Wise Guy]

Did you clear the code then it came back? I looked up the code in my reader and all it tells me is what you already know.

 

[ZO6_Vette]

Good possibility its the injector. had that happen to my 4.6 grand marquis.
If that does not solve it then I would replace the plug again and if it still is a issue do a leak down test on 6.

 

[swetrid]

Could be spark plug, make sure spark plug well is not filled with water also.

 

[bojans]

So now I have replaced the plug, injector and coil and I still have an intermittent misfire on #6. After pulling the plug and seeing some brown crusty deposits I couldn't ignore it anymore... I need an intake gasket, probably upper and lower. Anyone ever done this job? how long should it take a well equipt weekend warrior?

 

[adam06mount]

update?

did u do the intake? was it the cause?

 

[bojans]

Have not done the job yet, I have determined the main culprit is very cold temps. When the exterior temp is very cold the block and the intake are warming and expanding at different rates and until the intake comes up to the same temp as the block there is a leak. We have had much warmer temps recently and I haven't been having the problem. I am going to do the intake as well as a new radiator, accessory drive belt, etc this spring. We just had our second child 3 weeks ago so right now spare time is rather scarce.