[FortMillion]

Hey guys. I just replaced the Cam, lifters, water pump, fuel pump, head gaskets, etc. and I have the strangest issue.
the truck fires and runs a little rough without the exhaust connected. When I attach the exhaust, the engine sounds like likes it’s running on 4 cylinders and stalls after a few seconds. I cleaned the O2 sensors but have the same issue. I’ve ordered new O2 sensors. Is there anything else that can cause this?!?
This is my first post on this forum and would really appreciate any help. I also have video but don’t know how to post those.

 

[FortMillion]

Should mention it’s a 2012 Ram 1500 with the 5.7L Hemi. The cam lobe for #5 exhaust was shot.

 

[charged392]

Make sure all the pushrods are still in place it’s more common than you think for one to pop out on first start.

 

[FortMillion]

Make sure all the pushrods are still in place it’s more common than you think for one to pop out on first start.

Will do! Thanks for the input!

 

[SUPER BEE]

 

[Mrs.Studmuffin]

Welcome to our Hemi Family!!

 

[Ghost03hemi]

Welcome to HTC.

 

[arocketman]

Hello and Welcome to the HEMI Truck Club Forum. Enjoy your Ride and the Site.
You'll find some knowledgeable and friendly people to answer your questions or just entertain you.
Glad you could join us!

 

[RacerX]

Did you flush the oil galleries and flush the vvt assembly on the cam and also the lifter solenoids? Could be cam advanced with the vvt cam gear or its disabled the lifters on the 4 cylinders.

 

[FortMillion]

Will do! Thanks for the input!

So I took the valve covers off and hand crank d the engine over. Three exhaust valves on the passenger side weren’t moving. The push rods where engaged with the rockers. I feared a broken cam. Pulled the assembly off and put one push rod in at a time and pushed with my finger while I rotated the crank. They all moved just fine. I reassembled the exhaust valve train and rotated the crank again and everything moved correctly. I have no idea why they didn’t move before. I put it back together and it runs great! Thanks for the help.

 

[charged392]

They were likely not sitting on the lifter. Glad it’s good to go now!