Yet another P0305 Cylinder 5 Misfire Problem, Ram 1500 Hemi
Registered User
Joined: Sep 2023
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Sorry, I forgot to closeout this thread... It ended up being that the exhaust valve seat was dropping and wouldn't let the
valve close all the way. I was able to discover this by pulling the valve cover and having someone cranking the engine.
You could see the rocker was not moving as far as the others.
Ended up having to pull the heads, it was a major disassemble to replace them. If your going to replace the heads,
get aftermarket exhaust stud/bolts and make sure your machine shop guy peens the edge of he valve seats to keep them
from working there way out.
valve close all the way. I was able to discover this by pulling the valve cover and having someone cranking the engine.
You could see the rocker was not moving as far as the others.
Ended up having to pull the heads, it was a major disassemble to replace them. If your going to replace the heads,
get aftermarket exhaust stud/bolts and make sure your machine shop guy peens the edge of he valve seats to keep them
from working there way out.
New Member
Joined: Apr 2024
Posts: 1
Likes: 0
Did you figure it out?
Hi Folks,
Like many other, I have the cylinder 5 misfire problem. I have run out of ideas. Here is what I have done:
1. Replaced Cylinder 5 Spark plugs
2. Replaced Cylinder 5 Coil Pack
3. Swapped Cylinder 1 and 5 Coil packs
4. Swapped Cylinder 1 and 5 Fuel Injectors
5. Replaced Cylinder 5 spark plugs with premium type
6. Scoped both cylinder 5 spark plug holes for deformities or leaked oil from valve cover gasket (none found)
7. Did a compression check on Cylinder 5. It was around 200, which in my opinion is great.
This is on a 2012 Dodge Ram Laramie Longhorn with the 5.7 Hemi.
Anyone got any other ideas on what I can try next ?
Thank You,
Eric
Like many other, I have the cylinder 5 misfire problem. I have run out of ideas. Here is what I have done:
1. Replaced Cylinder 5 Spark plugs
2. Replaced Cylinder 5 Coil Pack
3. Swapped Cylinder 1 and 5 Coil packs
4. Swapped Cylinder 1 and 5 Fuel Injectors
5. Replaced Cylinder 5 spark plugs with premium type
6. Scoped both cylinder 5 spark plug holes for deformities or leaked oil from valve cover gasket (none found)
7. Did a compression check on Cylinder 5. It was around 200, which in my opinion is great.
This is on a 2012 Dodge Ram Laramie Longhorn with the 5.7 Hemi.
Anyone got any other ideas on what I can try next ?
Thank You,
Eric
Registered User
Joined: Mar 2025
Posts: 4
Likes: 0
I know this is an old thread. I just got a P0305 code. The engine idles normally. There is no hesitation on acceleration and the truck appears to perform normal. It's due for a spark change so I plan to do that. Also going to swap coils with another cylinder. Is there a trick to getting out the coils and plugs on the drivers side cylinders 5 and 7?
