Oil psi problem when starting truck
When I start up my GMC 1500hd 4x4 that has a 6.0 engine with 248,000 miles I have low oil psi. It is low enough at times that the truck has shut down. I can let it warm up (when it's cold weather) for about 10 minutes and drive down the road for about 7 miles and I then have 40psi on my oil psi gauge
The oil pump filter screen maybe partially clogged can try flushing motor with an engine flush.
So you notice no knocking (bearings) or ticking from the lifters? If not, there is a fine screen type basket under the oil pressure sending unit that has to be fished out and cleaned, as it gets gummed up blocking a true oil pressure reading. Replace the oil sending unit since it is out, your there anyway.
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