Bill M. From Illinois
Member
I had a spare 2N engine I had rebuilt last fall to replace the working engine that was smoking bad ,fowling plugs and low oil pressure. New sleeves, pistons ,rings and valve train has it running great, quiet and starts easy. Oil pump had new gears installed. I plastigage on rod bearing for kicks and it came out at .0015. Machinist said he checked all journal clearances and also camshaft and oil pump bearing. Had all this done for a modest fee and I was glad as the crank did not need reground and rod and main bearings were OK according to machinist. Well, now to the oil pressure. I used Rural King 10w30 for break in and oddly the pressure was super high on cold start ( pegged 50 PSI gauge) but would drop to less than 5PSI when hot Idle. I changed oil to Rotella 15w30 hoping it would help low pressure at idle but it did not help. Looks like I will be pulling this engine again. Again, the engine runs like a well oiled sewing machine and seems odd the pressure drops so much between cold and hot . What is most likely culprit? Spring and plunger on oil relief look OK but has not be en changed and common sense tells me it may cause high oil pressure but not low. Thanks for any suggestions. Bill