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Virtual Wrench
Virtual Wrench, Chevy Mechanic
Category: Chevy
Satisfied Customers: 14618
Experience:  35 years Master Mechanic
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2001 gm: 5.3 no oil pressure at startup cold..rpm..oil pan..gasket

Resolved Question:

2001 gm 5.3 no oil pressure at startup cold. pressure ok after rpm increased. oil pan is off & no problems found with pick up screen or tube gasket
Submitted: 10 years ago.
Category: Chevy
Expert:  Virtual Wrench replied 10 years ago.

Hello,

Weak oil pump, when it heats up the crecent gear expands and reduces the clearances between the gear and housing.

 

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Virtual Wrench and 2 other Chevy Specialists are ready to help you
Customer: replied 10 years ago.
Reply to Virtual Wrench's Post: is there a way to test the pump to see if there is to much clearance before taking it off
Expert:  Virtual Wrench replied 10 years ago.

It's pretty tough, you might get the pump opened, but you will have a problem holding the gears in place. It's better to bench test it.

LJ