My 5.3 vortec lost 20lbs of oil pressure and his a lifter tap
Have the oil pressure verified with a manual gauge. How many miles on this vehicle?
you need to find the one and look at the travel up and down of the spring / rocker arm..lifters and cams go out pretty quick..
If you have lifter noise then for sure the oil pressure has tanked, now you may need a new oil pump or something has happened internally with the bearings, too much clearance.
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