Quote:
Originally Posted by Dzmitry
Trying to understand this more. Does the oil always take a couple seconds to hit the bearings on cold start? Thought it might be quicker even with its thickness.
Or is this because you are saying he already has some kind of damage and therefore slowing down oil flow in some way?
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Quote:
Originally Posted by Sniepster
+1
I am also quite perplexed as to how would this happen. It is 5w40 after all, not a thick-ass 10w60 racing oil.
And i find it weird the issue has started happening during the hot summer months (when the oil is already warm and should flow quite well) and not during the freezing temps in winter.
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Anyone with an oil pressure gauge will confirm. It takes over a second for the oil to reach the journals after the galleries have drained. This is normal and referred to as transition from boundary, to hydrodynamic lubrication. Boundary lubrication is fine as long as heat generated by working the lubricant doesn't cause the temperature to rise - and viscosity to lower - to the point of allowing contact between the journal and bearing surfaces. Boundary lubrication is the dominant mode in applications where slow-moving parts are lubricated with grease.
The problem with worn bearings is that the gap is wide enough to allow the cyclic loads to overcome the boundary. We get that hammering effect. That's where it all goes to shit.