Well, I'm looking for some help!
I have a 2010 Dodge Charger R/T with 70,000 miles.
I have had the dreaded p0303 code.
1st thing I did was change spark plugs. (Cleared Code)To no avail, the code came back.
2nd I ran a compression test. 155 on cylinder 3 and (* 255 on all others If my memory serves me right). 😯So, I know compression is low on numbee 3 cylinder !!
So I did a leak down test and was only at a 9% loss. I could hear air escaping through crankcase.
I did scope cylinder and it looked like cylinder was in good shape. ( Seen cross hatched on walls) No noticeable wear.
So, where should I look next?

Thank you in advance.

 

two ideas...


what about doing a wet compression test on number 3 to see if the compression comes back up significantly.

does this engine have cylinder deactivation and is 3 one of the cylinders that gets shut down?


255psi seems pretty high compression readings

 

It may have been 225. Yes, it does have MDS. I even went as far as pulling out the solenoid for that cylinder and it worked when I put 12v to it.
As far as a wet compression check, the closest thing I did was throw some Seafoam in the cylinder the other night and let soak before changing oil. Just to see if a compression ring may have been varnished/stuck.

 

What I find odd is that I have low compression on #3 but the leak down only indicated only a 9% loss.
This leads me to believe that the lifters on that cylinder are "stuck" I've read how the MDS works and this is how I've came up with my "so called conclusion " ! 😆

 

have seen a lot of collapsed lifters on the gm active fuel management 5.3L. usually we get 0 compression. replacing the afm lifters fixes it. I haven't done and dodge engines.


the oil condition and level were good on this engine?


what was the supply air set at for the leakdown test?

 

Oil level and condition is good. Changed at needed intervals.

I ran the air supply to 75 psi as stated in the book. Said not to exceed 80.

I am leaning towards the lifter...but just wanted someone with more experience than I do.

 

sorry to hear about your car. did you find the culprit of your problems? i have a magnum with a hemi and i am having a similar issue...i made a more complete post in the magnum section, if you are interested. i just thought i would get as much info as possible before i do anything.