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Discussion Starter #1
2005 armada, got it started with help from here and a locksmith. Now it has engine ending sounds. Has anyone had experience with timing chain issues on these or engine failures. What is the preferred way to upload video?
Thanks!

Engine noise video.
 

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Well it doesn't sound nice.
There's way to much going on there for my ears to give you anything educated.

Personally I hear really aggressive metal-to-metal, that's what is almost making that squealing sound.

How was the oil? Contaminated? Metal?
I'd start with timing and then compression check.
 

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Well first, change the oil and visually inspect it. If you see chunks.... next send some to Blackstone for analysis.

Could be intake and exhaust leaks. Smoke test the evap system and exhaust system.

Then pull the plugs and inspect.

Still clear, then compression test. That should cover engine ending stuff, but it sounds like a squeak.
 

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Discussion Starter #6
Did the compression test, cold obviously. The left bank is all around 120. The right bank is 90,90,120,90. Looked at the oil again and still don’t see anything obvious. There’s no metal hitting metal noise on crank, only when running, but it sounds off somehow I can’t articulate when it cranks. I pulled the right bank timing cover and the chain is there and taut. The spark plugs appear old and like it was running rich. Gonna borescope the right bank I think to see if there’s obvious valve damage to a piston.
49419
49420
 

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It won't hurt to check but did you look at any of the accessory pulleys and auto-tensioner to see if anything seized. Also, any DTCs?
 
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It’s not throwing a single code at all which is frustrating. All the pulleys and accessories appear to free spin just fine. I dropped the lower oil pan and there is fine metal pieces in there, but small and not a ton of them. Not sure what from. Very flat pieces.
 

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It’s not throwing a single code at all which is frustrating. All the pulleys and accessories appear to free spin just fine. I dropped the lower oil pan and there is fine metal pieces in there, but small and not a ton of them. Not sure what from. Very flat pieces.
If possible, borrow/rent a borescope to look for any signs of damaged valves, piston heads and possible scoring on the cylinder walls.
 
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Discussion Starter #11
So I’m not very good with a borescope, especially getting it down those long spark tubes. Nothing screamed at me as bad, but I’m not sure what exactly I’m looking for. I thought this was a hole at first but just a weird mark? The metal appears shiny around the piston edges
49421
 

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The shiny edges looks as if the piston head has a hole or a valve slammed into it leaving that indentation. Either way, it doesn't look good.
 

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Did the compression test, cold obviously. The left bank is all around 120. The right bank is 90,90,120,90. Looked at the oil again and still don’t see anything obvious. There’s no metal hitting metal noise on crank, only when running, but it sounds off somehow I can’t articulate when it cranks. I pulled the right bank timing cover and the chain is there and taut. The spark plugs appear old and like it was running rich. Gonna borescope the right bank I think to see if there’s obvious valve damage to a piston. View attachment 49419 View attachment 49420
Those are very low compression numbers. Not that I know what they are for this engine, but I don't know of any current engine that is below 150.
 

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Pilotn8, you're not going to like this, but compression #s for the VK56DE are:

Standard- 220 psi / 200 rpm
Minimum- 192 psi / 200 rpm

I'm sure if you were to pull the cylinder heads off, you'll find the valve(s) that damaged that piston head.
 
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Discussion Starter #16
Well that isn’t good. Think I may have sourced a new engine. Going to pull this one somewhat apart still to see for sure what failed. Almost have it out, just waiting for the engine slingers from Nissan. I’ve never had to buy slingers for an engine before.
 
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