Ok im new at this, but here goes.

I have a 2006 dodge 1500 bighorn 5.7 liter hemi with 174 thousand miles, about two months ago i got a code for #1 cylinder misfire and the code for wrong oil type along with a loud pop on start up with a misfire. The truck runs very rough until it warms up then will run great hit the pedal and the power is there. Ill go ahead and admite the truck calls for 5w-20 and i have used 5w-30 since the truck was new because of the warm temps in mississippi, didnt think it would matter much, but in this case it maybe the downfall.

I started out by replacing the plugs, moved the coil packs, replaced the EGR valve, new injector all with no luck. So tonight i pulled the valve cover off, placed all the coils back in and started up the engine and could see that the intake valve on the #1 cylinder would work for a few seconds then it would make the loud pop and the valve would stay closed causing the engine to begin to misfire. My question i need the answer to is what do i need to try and fix first. I have the MDS soleniod already but could this be what is causing this or is it a lifter or could it be the PCM. I know it has to be one of the three, and i really do not wanna remove the head to get to the lifter. The part that is really getting me is the wrong oil type code, could this have made that soleniod go bad or should i go ahead and replace the lifter since i have everything already apart.

Thanks for any help you guys can give.

 

try putting 5-20 in it first. See if that fixes your issue.

 

I did also went ahead and changed the solenoid for the #1 cylinder and had no luck. I think the lifter has gone bad, so I'm about to find out how long a hemi will run after a lifter has gone bad.