Shaun Toole

My neighbor worked as a machinist for GM, the other an engineer for them but only on conflicts. This forum has been super helpful to say the least because “just replace it” isn’t helpful on a $6,000 engine. I’ll post a follow up when I get it back together. It’s a very doable project considering I’m doing it on a gravel driveway in 90 degree weather.

I did use one, the knock only resonated through one cylinder, but all lifters, injectors, and valves were functioning and consistent. I didn’t check the oil pan with it, but did pull it today and it is a rod bearing failure.

I have a new question, the crank and rods do not have visible signs of wear fitting metal on metal contact. What I mean by that is the are smooth with no tracking. However, I am noticing where the bearing was shot that the crank has a noticeable step on the compression side and if I didn’t know any better I would assume it was turned that was. Is it possible to just replace the bearings or do I need a new crankshaft?

Then that is what I shall do! Is it possible to get to the rod bearings without pulling the engine? Or is it best to do a full exploratory inspection?

What is snake oil? I’m am certain all of the issues when I bought it were tied to poor maintenance with the oil.

Here’s a video of the knock. A couple of updates since the post. All check engine lights are clear, the OBD code is p0011. Just incase it was advanced, I checked resistance and output of the knock sensors and replaced them. The oil pressure has increased at idle to ~32-35 at cold start. The flush oil and the current new oil is Castrol Full synthetic with a STP filter 5w30. All of the lifters are new, all of the push rods cleaned straight, all of the rockers and springs appeared to be in good condition.

My apologies for the selection on year but I’m hoping someone has experienced the noise I’m hearing. I bought a 2009 Yukon Denali with the 6.2L and it has a knock that seems harmonic with cylinder 6 and also audible through the water pump. When the rpm’s are increased above idle it sounds like marbles in a can. The only code (and no light) is a p0011. Engine oil pressure at idle is just below 20 and at 25 when rpm’s are brought up (seems low). Immediately after purchase I have done the following; 1. Oil change with sea foam detergent. 2. Oil pressure sensor. 3. Full swap and inspection of lifters. There was no obvious damage. 4. Cleaned push rods. 5. New plugs and wires. 5.b Changed oil again after 10 minutes of idle. 6. Clean and inspect Oil timing valve. 7. Replace VVT solenoid. 8. Replace Camshaft positioning sensor. The engine idles well at 550 but knocks loudly. At any increase it sounds like marbles. Any thoughts on what I should be looking for?