AOS - Question

[SeanBuller]

Thanks for the prompt responses!

We do not yet have a Durametric, we will be able to determine how retarded it is once we get that information. It's hard to locate the noise as we are afraid to run the engine for too long. What are your thoughts on running it and holding it at 1800 - 2000 RPM while we locate the noise?

It makes sense to be the hydraulic lifter, but I am confused why the code is showing up saying P0012. Could that just be a red herring?

Gelbster, those are good questions. Unfortunately I don't know enough about engines to answer them.

Thanks,
Sean

[Gelbster]

In theory - and I stress theory! -you could disconnect the knock sensor on that bank and see if the retard goes away.
I would be too timid to do that. I would rather locate the source of the noise. Based on your video, it sounds too loud to be a lifter.One collapsed lifter makes a ticking noise.Your noise sounds 'bigger' like a heat shield/exhaust banging together. Hopefully not a bearing. But a noise generated outside the crankcase would not activate the knock sensor .
Before you start dismantling the engine, please understand this is not a simple task, nor inexpensive. Get skilled,knowledgeable help.The M96 is very unforgiving !

[911monty]

Unless I'm mistaken, the knock sensor only retards ignition timing, not cam timing. Knock is typically due to low grade fuel burning too early in the compression stroke causing detonation and piston knock. Cam timing changes optimize low end torque or high end horsepower.

Seems strange to have good compression, with a severely retarded cam. I might suggest pinning crank at TDC cyl #1, pull the cam plug and see how the timing marks line up. I would expect to see the bank 1 cam a few degrees off. I'd then rotate the crank 360 degrees while observing bank 1 cam and make sure it rotates.