Bad miss or knock... (Video)

87jumpy · Dec 10, 2011

I can open it up and look, that's not a problem. I am going to pulling the cab soon for headstuds and gaskets, so I was wanting to get the rest of this all together

87jumpy · Dec 16, 2011

So I have the drivers side valve cover popped off, can't see or feel anything wrong... any suggestions on what to look for or do next?

87jumpy · Dec 16, 2011

I took the fuel rail off and saw this...

#4? Intake Push rod bent.

Can I pull the retainer off, replace the push rod and torque it back to spec or do I need to put the engine in time first?

Would this cause #8 to misfire?

Dzchey21 · Dec 17, 2011

87jumpy said:
I took the fuel rail off and saw this...

#4? Intake Push rod bent.

Can I pull the retainer off, replace the push rod and torque it back to spec or do I need to put the engine in time first?

Would this cause #8 to misfire?

which valve cover is this?

87jumpy · Dec 17, 2011

Drivers side

Charles · Dec 20, 2011

That's what your video sounded like. Classic intake valve sound.

And depending on firing order one cylinder will certainly throw a contribution on another. Hopefully you can replace the pushrod and all will be well. Check that rocker VERY well. I don't know how the 6.4 looks, but on the 7.3 (cheesy rockers I know..) the little "cup" in the rocker at the fulcrum is prone to "crushing". Check things like this as well.

Talk to others who have experience with the 6.4 so you know what the common modes of valvetrain failure are and look for them before buttoning it back up. Check the other cylinders for signs as well.

87jumpy · Feb 13, 2012

Well here is a little update...

The pushrods after Matt got them dug out of the heads

Truck also has 2 cracked heads and 2 melted pistons.

Matt may throw a few more pics up

Erikclaw · Feb 13, 2012

Damn, that was a little more than just a bent pushrod. Was it driven after you first posted the bent pic?

87jumpy · Feb 13, 2012

Erikclaw said:
Damn, that was a little more than just a bent pushrod. Was it driven after you first posted the bent pic?

Nope, pushed it onto a trailer and hauled it to the shop

Charles · Feb 13, 2012

Cracked heads mean little, and the pistons were probably melted for a while. The pushrods were probably all you noticed, and all that needed immediate fixing.

Truck would have probably driven exactly like normal with the other problems, unless one of the cracks went all the way through, or the pistons got down to the top ring.

My heads have been cracked for years now. I don't even bother trying to replace them anymore. They've been back on once or twice after they were taken off and seen to be cracked. Other than welding in seats and grinding them back flush, I don't see a practical solution, so don't see much sense in worrying about cracked heads that don't penetrate a coolant or intake passage. New ones will probably crack again in short order.

Was the compression down? Why did the engine get torn apart in the first place?

87jumpy · Feb 14, 2012

I don't believe that Matt did a compression check. Engine was torn down to do studs and head gaskets along with replacing the pushrods.

Charles · Feb 14, 2012

87jumpy said:
I don't believe that Matt did a compression check. Engine was torn down to do studs and head gaskets along with replacing the pushrods.

Oh, I got you.

On Edit:

I went back and re-read the first post, and it seemed like everything was cool, except for jumping in the truck one morning and having the classic poop, poop, poop sound out the intake. Unless you were just already planning to pull the heads, I would have probably replaced the bent pushrods and rolled out, lol.