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Ask -Brad- Your Own Question
-Brad-, Dodge Dealership Tech
Category: Dodge
Satisfied Customers: 7993
Experience:  16 Yrs Chrysler/Dodge Technician. ASE Master Certified(L-1)
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Have a 2012 ram 3500 5.7....p0306 code....changed all the

Customer Question

Have a 2012 ram 3500 5.7....p0306 code....changed all the spark plugs (16) changed the coil pack and injector, checked the compression on that cylinder checked ok...checked voltages to the injector and coil pack...the problem now seems to be that the code won't release for some reason it's marking it as a permanent code...why? Is there a way to remove it or is there another reason why it's still showing even though there's no "problem "
Submitted: 11 months ago.
Category: Dodge
Expert:  -Brad- replied 11 months ago.

Good afternoon and welcome to JustAnswer!!

My name is ***** ***** I have worked for a Chrysler-Dodge-Jeep dealership for 19 years and I will do my best to help.

What is the compression for #6 cylinder? Can you feel it misfiring? Have you swapped coils?

Talk soon,


Customer: replied 11 months ago.
Compression shoots up to about 140 -150 and is able to hold misfires when I accelerate up to the 3 of 4 k rpm ...but if it's idling or cruising along it won't show the blinking check engine light I have swapped coils and it's also a new coil pack
Expert:  -Brad- replied 11 months ago.

And you performed the compression test by removing the ASD relay and cranking it over a few times? What do you mean by able to hold it? If your talking about the compression gauge then it has a schrader valve which will hold the pressure as there is no way for the cylinder to keep constant compression. Also if you can erase the code with a scantool will it come back if you sit and rev the engine, how about if you power brake it?

Customer: replied 11 months ago.
to the first question...aND able to hold as in the many times it was tested each time it showed good not mechanical...we've erased the code with the scanew tool and removing battery and either way it'll come back, power braking it, sitting and revving it, driving it then punching the gas...the scan tool will still pick up the code even after its erased and show at bottom of screen as a permanent cousin was saying something about the trucks computer won't release it even though nothing shows up wrong in the engine and that maybe it needs to be done by the dealer?
Expert:  -Brad- replied 11 months ago.

When you erase the codes with a scantool they are gone for good, when you start it up and the computer see's the misfire again it will set the code again as an active code meaning it's misfiring right now. #6 cylinder is the 3rd one back on the passenger side, and if the compression is good and the same as the other cylinders then your loosing spark or fuel, and since you have swapped coils have you swapped injectors? If you erase the codes and let it idle can you feel it misfire and will it set the code before you rev it up?

Customer: replied 11 months ago.
Yea we checked compression next was the spark and we checked it and there's good spark...the injector so also new and also swapped our for a different position...we even swapped the new spark plugs with old ones aND swapped back and still get the same thing..we pulled off the fuel rail and there's fuel shooting out of all 4 injectors evenly, if the codes get erased the check engine light turns off but on the scan tool it'll still show it there as permanent even after turning on the truck no check engine light but the code sits in the scan won't misfire while idling and u can tell from the engine it's got no problems but as soon as it does its a night and day difference in power
Expert:  -Brad- replied 11 months ago.

If it won't misfire at idle and the check engine light is off then will it misfire as soon as you press the accelerator? The compression for #6 was 140-150, what was cylinder #4 and #8 compression readings? We are seeing quite a few lifter issues which will cause this.. Can you remove the valvecover and remove the ASD relay and crank the engine over and tell me if the rocker arms on cylinder #6 move just as much as the cylinders beside it?

Customer: replied 11 months ago.
I will check the valve cover today when I get home that's something I haven't done...I don't know if it makes a difference but I'm a hot shot driver...the truck has 163k on it and just before it started giving me this problem I had ano 1100 mile trip up to new Mexico with my 24ft gooseneck loaded with 9k lbs...I will get back at you later today
Expert:  -Brad- replied 10 months ago.

What did you find?