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Dan
Dan, Auto Technician
Category: Chevy
Satisfied Customers: 3490
Experience:  GM Mark of Excellence/ Service Guild Participant with 13 years experience, ASE Master Certified
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1999 Chevy Tahoe: oil pressure..As it warms..pressure keeps going down

Resolved Question:

I have a 1999 Chevy Tahoe (Vortec 350). When I start the car when it is cold, I get 60 psi of oil pressure. As it warms up and I drive the pressure keeps going down. Stop. Then restart I get 40 psi oil pressure. The more I do this, like in town, pressure keeps going down. Last time, when I got home I had 5psi of oil pressure. What is up?? Bad oil pump????
Submitted: 9 years ago.
Category: Chevy
Expert:  Dan replied 9 years ago.
Are you using good quality oil? Have you installed a manual oil pressure gage and see what that shows for pressure compared to the actual reading on the gage? How many miles are on the engine?
Customer: replied 9 years ago.
Reply to Dan's Post: I use Valvalene 5-30. Nothing has been changed. Manual gauge reads just as the dash reads. at idel 20psi
Customer: replied 9 years ago.
Reply to Dan's Post: I use Valvalene 5-30. Nothing has been changed. Manual gauge reads just as the dash reads. at idel 20psi Car has 151,000 mmiles on it
Expert:  Dan replied 9 years ago.
Engine Mechanical Specifications (5.7 L)

Application

Specification

Metric

English

General Data

  • Engine Type

V8

  • Displacement

5.7 L

350 CID

  • RPO (VIN Code)

L31 (R)

  • Bore

101.63 mm

4.0012 in

  • Stroke

88.39 mm

3.480 in

  • Compression Ratio

9.4:1

  • Firing Order

1-8-4-3-6-5-7-2

1.52 mm

0.060 in

  • Oil Pressure (Minimum at Normal Operating Temperature)

42 kPa at 1,000 RPM

125 kPa at 2,000 RPM

166 kPa at 4,000 RPM

6 psig at 1,000 RPM

18 psig at 2,000 RPM

24 psig at 4,000 RPM

Dan and 4 other Chevy Specialists are ready to help you
Customer: replied 9 years ago.
Are you saying that my tahoe is running normal??