Quote:
Originally Posted by chris719
Based on what I have seen from reading basically every S65 and S85 thread here and on M5board, I am skeptical that even a 100% complete Blackstone history will let you know if/when you need to replace rod bearings, even with earlier production bearings containing lead.
I certainly wouldn't rely on low / consistent lead levels and conclude you don't need to swap out your bearings at high mileage or something. Without a detailed analysis of their methods, it's just a guess. For example, factors that matter could include what kind/size of particulates the rod bearing wear produces and how it interacts with the filter media.
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S54 has issues with the rod bearings and they are made of copper and then coated. If you see elevated copper levels on this engine there is an excellent chance this is where it is coming from. The fix is far less expensive than the complete engine rebuild.
See below.
https://www.zpost.com/forums/showthread.php?t=1493760
[I]Lead – Usually a soft metal, most common related to bushings and Rod Bearings. Engine oil which are highly oxidized can attack the bearing material, leads to increased lead readings.
Iron – Mostly comes from Cylinder liners, Rings, Crankshaft, Camshaft, Rods, Valve Train, Oil pump gear, Wrist pins, cast iron components and Gears. Usually found as fine particles due to abrasion or wear.
Aluminium –Generally comes from Pistons, Turbo Bearings, Main and Rod Bearings, pumps, thrust bearings and washers, plates and Aluminium castings. Aluminium associated with silica indicates dirt. Aluminium found in hydraulic system should be generally due to dirt ingestion and in final drives can be associated with dirt or sand.
Copper – Usually like a soft metal present in Main and Rod Bearings, Oil Cooler core, Clutch plates, Brass and Bronze bushings and Roller bearing outer cage. In engines it should be due to the water pump leak or coolant core. If it is found along with potassium, sodium and glycol, it will be coming from the oil cooler.
If it is found along with lead and tin, it will be coming from bearing or bushing.[/I]