OBD Code P0106 and P0306 (Fixed)

[K4_Khalid]

Hi, Yesterday all of sudden my car 2010 ford explorer 4.0 began to misfire and hesitate. First engine light was blinking than it stayed solid. OBD scanner pulled error code P0106 and P0306. Took car to a friend mechanic and he said p0106 code could be linked to p0306 so we should work on code p0306 and I changed spark plugs, checked spark plug wires and coil. Also checked injectors and cleaned all of it. After that I cleared codes. Idle is still rough, misfire same like before. After driving few minutes I got both codes back. According to mechanic problem is from internal component, cylinder or value etc.. for which I'm not convinced .. any help will be highly appreciated. Thank you

 

[Rcflyer330]

Okay cylinder 6 misfire. we know the coil is good because the 4.0 uses what's called a waste spark design. two plugs fire on each ignition cycle one cylinder will be exhaust the other will be on compression with fuel air mixture. you only have one cylinder miss so the coil is good with a bad coil you will have two misfire cylinder codes and they will be companion cylinders (for example 3 and 5, 2 and 4, 1 and 6. these may not be correct for this motor). so we are left with a couple options fuel, the plug wire ,and internal damage. how did you test the wires and fuel injectors?

a compression test on cylinder 6 will rule out internal damage from compression loss. try holding down the accelerator pedal to full and try starting the car listen to how it cranks it should be smooth and consistent (the car will not start with pedal at full throttle). this is a easy check you can do but an actual compression test should be done.

fuel injector wiring could have problems on injector 6. the wiring has been known to degrade and crack over time causing a problem. its worth checking the wiring to injector and to the maf sensor for that p0106 code.

That's all I can think of at the moment report back with your findings and answers to my questions up above then we will go from there.

 

[K4_Khalid]

Okay cylinder 6 misfire. we know the coil is good because the 4.0 uses what's called a waste spark design. two plugs fire on each ignition cycle one cylinder will be exhaust the other will be on compression with fuel air mixture. you only have one cylinder miss so the coil is good with a bad coil you will have two misfire cylinder codes and they will be companion cylinders (for example 3 and 5, 2 and 4, 1 and 6. these may not be correct for this motor). so we are left with a couple options fuel, the plug wire ,and internal damage. how did you test the wires and fuel injectors?

a compression test on cylinder 6 will rule out internal damage from compression loss. try holding down the accelerator pedal to full and try starting the car listen to how it cranks it should be smooth and consistent (the car will not start with pedal at full throttle). this is a easy check you can do but an actual compression test should be done.

fuel injector wiring could have problems on injector 6. the wiring has been known to degrade and crack over time causing a problem. its worth checking the wiring to injector and to the maf sensor for that p0106 code.

That's all I can think of at the moment report back with your findings and answers to my questions up above then we will go from there.

Thanks for fast response, My elder brother has same trim 2006, I checked coil and spark plugs by swapping. Injectors were removed and cleaned individually and checked by turning ignition on while manifold removed, all were spraying good. Thanks for explaining me about compression test. I am going to perform me today definitely. I will update you with results. I checked wires for code p0106. All look good, I found some multimeter testing ways which I will do next. Car is well maintained, engine wire and all visible components in excellent condition. I’m bit surprised about getting both codes once. Is there any kind of possible link between these codes?

 

[Rcflyer330]

I dont know much about what codes can go together and what direction to take. Usually the factory service manual will have each code and directions to take with other codes present. That can be found online with services like alldata or alldata diy. I see in you profile that you are from Saudi Arabia so i dont know if you could access them but alldata diy in the USA is something like $20 usd for one month access try searching for it on the web see if you can get it.

But before you spend money try the crank test first then get a compression test.

 

[96eb96]

 

[K4_Khalid]

I couldn’t find how to do crank test but I did compression test and 1-5 cylinder readings were between 180-200 PSI cylinder 6 zero (0) PSI. I think it’s confirmed now that it’s internal engine component problem. Could be valve cylinder rings .. any suggestion before mechanic will begin working on it?

 

[Rcflyer330]

With zero compression could be a couple of many things valve problem (i think that is more likely) or the broken connecting rod hole in the top of the piston none are not good. The crank test was hold the throttle at 100 and try starting the car it should crank and be an even sound. Its the same way you do a compression test just without a compression testor. The cylinder head is goin to need to be removed to find the cause.

You may want to start looking for a used or rebuilt engine. If you have access to a bore scope you could look into cylinder 6 and see if its a valve problem or piston problem.

 

[K4_Khalid]

I don't think here in Saudi Arabia I can find used or rebuilt in good condition, besides I just done OEM tensioner guides kit job 6 months ago. I ordered bore scope, once I receive it I will look into cylinder.

I love this car. If I repair this problem, should I just fix this exact problem which is related to cylinder 6 or since cylinder head will be removed I should take care of other part to prevent any future damage. Any suggestion?
I want to keep engine reliable as much as it could be.

 

[96eb96]

I don't think here in Saudi Arabia I can find used or rebuilt in good condition, besides I just done OEM tensioner guides kit job 6 months ago. I ordered bore scope, once I receive it I will look into cylinder.

I love this car. If I repair this problem, should I just fix this exact problem which is related to cylinder 6 or since cylinder head will be removed I should take care of other part to prevent any future damage. Any suggestion?
I want to keep engine reliable as much as it could be

The bottom end of these engines are very strong.

Maybe it is something like a broken valve spring? Pull the valve cover and inspect.

 

[K4_Khalid]

The bottom end of these engines are very strong.

Maybe it is something like a broken valve spring? Pull the valve cover and inspect.

I did pull valve cover and checked all looked good.

 

[96eb96]

I did pull valve cover and checked all looked good.

Probably a borescope is your best bet.

 

[MakinJeepsWeep!]

Could be as simple as a valve cracked and a piece where it seats into the head is gone which will give you 0 compression.
I say as simple it isnt all that simple best hope is that may be the issue and its the exhaust valve and that is where the piece went as well out the back.

 

[K4_Khalid]

Couldn’t find any problem with borescope either. Pulled engine out and found out yes it was valve spring broken. Earlier checked but couldn’t identify it.

 

[K4_Khalid]

Thank God, car is fixed. Also P0106 code disappeared by fixing P0306 only.
Thank you everyone for fast responses and helping