6L V8 noise on cold start - Bottom end bearings v Lifters v Piston slap v Oil pump

[moveage]

Don’t do anything more mechanically without a log of oil pressure readings from the onboard diagnostic port.
The motor is relatively new, stock, engineered for 5w30, so unless you’re north of Capricorn and only drive during the light of day, don’t switch up oil grade in winter. This will starve critical components and well intended lay advice like that is possibly cause of the problem for which you have symptomatic relief right now.

 

[moveage]

so we were discussing an analogy to use to describe what might be happening. we came up with drying clothes inside your house. after one day they are mostly dry, day two - probably dry and day three or four - crispy dry. So he's suggested that by day 6 or whatever it was that there was absolutely no oil left anywhere in the motor other than the sump- it just keeps draining or 'drying' like the clothes. bearing clearances too great and allowing oil to drain off in it's entirety was thrown around too. He suggested 10/40 and move on to more important things in life

Air drying clothes inside a house is entirely dependent on vapour pressure, where the act is similar to throwing a litre of water into the air. Whereas you can leave oil coated engine components for several years under various atmospheric conditions yet still retain lubricant. The oil property that bonds to metal is not surprisingly called adhesiveness. This is defined as one if the 18 properties of oil.

 

[vombil]

Air drying clothes inside a house is entirely dependent on vapour pressure, where the act is similar to throwing a litre of water into the air. Whereas you can leave oil coated engine components for several years under various atmospheric conditions yet still retain lubricant. The oil property that bonds to metal is not surprisingly called adhesiveness. This is defined as one if the 18 properties of oil.

Ok. point taken and I suppose the Castrol Magnatec boffins might agree with you - i reckon it's not a bad analogy still though. I'm in court at the minute with a piston slap matter which acoustics vary primarily based on ambient temp and exposure to elements - in short, it's very noisey when parked outside in the cold. Had a 304 that was very blocked up (pick up) and was extensively driven with low pressure due to low supply. I cleaned the pick up but it was too late. The thing lost ALL pressure once warm. Not even 40/70 brought this thing back to life. 40 psi when cold down to literally 0 or maybe 2.... and a knock at idle, when up to temp. I def don't have this type of bearing issue in this rig. It's quite as a mouse when right up to fans on

 

[vombil]

Air drying clothes inside a house is entirely dependent on vapour pressure, where the act is similar to throwing a litre of water into the air. Whereas you can leave oil coated engine components for several years under various atmospheric conditions yet still retain lubricant. The oil property that bonds to metal is not surprisingly called adhesiveness. This is defined as one if the 18 properties of oil.

got the oil sample results. bloke phoned me (very unusual - i was told I'd get an email) and was like - that oil is absolutely perfect. He went as far as to say the motor appears to be in ''outstanding condition''. negligible levels of copper, nickel, lead and fuel which is what they test for among other things inc water. He was even able to guess the viscosity which I later confirmed in the service receipt was a 5/30 (assuming the dealer used what they advised which I know isn't always the case). The previous owner had put 8,000kms on that oil and it would have been religiously cold started after long periods of no use (FIFO worker) so if there was a noteworthy bottom end knock i'm guessing it would show in this analysis. still waiting on a chance to hook up the mech gauge.