asilverblazer

Compression test? Weird noises? Fuel trims?

I suspect at some point in the near future, the hardware will be free and you pay a subscription to access the vehicle - alldata style.

Can you sample the pooled liquid, enough to confirm it is oil? ...That its not fuel or coolant. Also, make sure combustion gases aren't entering the cooling system. Simply put, either oil being pushed up past the rings (this really isn't possible), oil leaking past the head gasket, oil leaking past the valve, oil entering through the intake air path. If none of this is likely - it may not be oil. What could be likely is the fuel injector leaking down. A puddle of gas would still smoke and rough idle. (Same cylinder has the same problem after injector replacement?) What is the crank time first thing in the morning, when the puddle would be present? Does it seem like the high pressure fuel pump needs an extra second or two to rebuild the pressure that injector 8 may have let bleed off? Check the fuel pressure via a scanner prior to starting the engine.

No.

I'm really curious to see what the O2 readings and timing looks like when you run it.

I have a hard time seeing oil from 'below' the rings 'pooling' in the cylinder. For an amount great enough to pool getting past the rings I would expect to see that same amount contributing to other noticeable symptoms, low compression, blow by, etc. You could try investigating for a stuck, gummed or carboned up ring, maybe an oil with different detergent strategy. Some other shade tree solutions like adding a detergent (or mystery oil) to the chamber and letting it sit, I've also heard of a heavy use of 'engine braking' to load the rings differently. I would first be looking at oil entering from 'above' via a head issue, or intake/PCV issue. I suspect that the oil is entering cylinder 8 combustion chamber at all times but is getting burned off during each combustion event preventing a 'pool' from forming and lessening visible oil burning smoke. This leads back to valve stems or PCV system as the only route for oil to enter the chamber from. I would expect a PCV issue to not be isolated to cylinder 8 though. Other considerations, how long does it take the pool to form? Could you look for the oil trail via the borescope? (Run the truck, shut the engine off, as quickly as practical, pull the plug and insert the scope and record to see how long and hopefully where from.)

Then why is it pulling timing so extremely at idle - but not at other more likely scenarios such as high load low RPM conditions? As a test, what would happen if the knock sensor was unplugged - revert to 'base' timing and see what conditions it defaults to and presents on the O2 readings?

There's a bunch of tea leaves that you've read, but in any case the delayed timing is unusual. Not sure how that relates to the rich at idle vs. 'normal' while driving. If you're in this deep, might be worth investigating, and re-learning the sensor. What have you got to lose? Plus, it properly fixes the timing cover leak.

The only problem I have seen this cause is longer crank times.

What are the conditions of this rich idle? Warm or cold engine? Run time? Does every idle look like this or only sometimes?

I had an alternator fail that was shorted internally in such a direct fashion in addition to the larger gauge cables that it appeared like a VERY dead battery. Granted I think the car did power up, it definitely wouldn't start. Rodent damage to wiring?

... I don't think he could.

Using experience to justify bad advice is lazy and typical of someone incapable of articulating why their advice is prudent. This immediately sets off the BS alert and the advice that followed certainly qualified. Asking an idiot for help getting out of dumb situations because he is an expert... at getting himself into dumb situations. Unless I've been living in an alternate universe - the first thing everyone does when getting into a sticky situation is shift to a higher gear . Of course not, the torque multiplication, mechanical advantage and finer control typically afforded by the lower gear is far better suited for this scenario. There ARE scenarios where a higher gear MIGHT be appropriate determined more by the drivers ability to control EXCESSIVE wheel spin versus applying torque to the ground.

Keep clearing the code and driving it to build more data on circumstances, the problem may become more constant, reveal itself or cause more symptoms that make diagnosis easier.

Some simple grounds from battery to engine, battery to frame, etc. using jumper cables might yield some clues. Battery condition? Alternator may have internally shorted - pull the power cable off the back if you suspect it.