Guys I need help figuring out this engine rattle

[Fless]

Pull the fuel pump fuse or relay, if there is one?

 

[iamdub]

Got the intake manifold and valve cover off on the passenger side today. I wasn't able to find anything wrong, I took the pushrods for #6 out and they all look nice and straight. The rockers for #6 look the same as the rest of them. I am a little confused, I thought I would see some evidence of damage by now. Tomorrow I will pull the head and hopefully see something wrong.

Here are a couple videos I took today:

Some rockers are gonna be easy to slide side-to-side and some will be locked up depending on where they're at in the cycle. If you turn the crank enough, you'll find that those locked ones will now wiggle and the others will be locked up.

And here is a clip of my lady turning the motor over for me. As you can see it appears that the valves for #6 work just fine, How do you disable the fuel pump? I pulled fuse #20 and the fuel pump relay but as you can see the fuel pump still works..

What are your guys thoughts here?

Oof. Yeah, I didn't mean to try the clear flood mode with the manifold off. I thought you were just gonna pop the valve covers off and crank it. These things with the fuel pump being controlled by an FSCM means removing the fuse labeled "FUEL PUMP" does nothing. Some don't even have that fuse or the relay in place. Try removing the one labeled "FSCM". I think it's #21.

 

[Dustin Jackson]

@iamdub Should I be concerned I haven't found evidence of damage up to this point? Is it still worth it to pull the head?

 

[iamdub]

@iamdub Should I be concerned I haven't found evidence of damage up to this point? Is it still worth it to pull the head?

Checked under the other cover yet? I know you said it sounded loudest on the passenger side. But, sound can travel through a block. Also, the lifter might not be collapsed and "just" turned in the bore. It'd still move the rockers and appear normal.

Unfortunately, it might not even be a lifter or even in the valvetrain. You might have a spun bearing. Either way, you're gonna have to dive deeper and the engine will almost certainly need to come out. The heads being off will only make this easier. After checking under the other cover, you have nothing to lose by pulling the heads. It's pretty much the next step in diagnostics.



Wait- have you checked your spark plugs to make sure they're all good and fully tightened? Although, it does sound lifterish or spun bearingish. Also, loose converter-to-flex plate bolts or a cracked flex plate can rattle. But, this wouldn't explain the misfire code.

 

[Dustin Jackson]

@iamdub I haven't checked the other side yet because the check engine light said it was a cylinder 6 so I only checked the passenger side for now. Tomorrow I will try to make some progress but it is fathers day

 

[Dustin Jackson]

Well I got the head off today and here is what I found:

 

[George B]

At least you found your culprit. I suspect thats just carbon bits down in the cylinder.

Should be a cam and lifters and run it repair.

 

[Dustin Jackson]

At least you found your culprit. I suspect thats just carbon bits down in the cylinder.

Should be a cam and lifters and run it repair.

Lots of junk for sure, all the metal seemed in condition

 

[FasterBass]

Lots of junk for sure, all the metal seemed in condition

How does the cylinder wall feel on #6? If you drag your finger nail around the inside of the bore, does it catch anywhere?

 

[TollKeeper]

Yeap.. Wiped cam, bad lifter tray, bad lifter, pushrods should still be good thou.

Good time to do a AFM/DOD delete if you want.