« previous next »
Pages: [1]   Go Down

Author Topic: ENG OIL PRESSURE  (Read 2067 times)

Offline CashpitC10

  • New Users
  • Posts: 1
  • Newbie
ENG OIL PRESSURE
« on: November 20, 2019, 01:48:38 PM »
Have 83c10 with a 305 just changed oil less than a month ago. When i stop at a red light or stop sign the oil pressure drops below 20lbs. What could be the cause of this? Any help would be great.    Thanks Jody
Logged

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6454
Re: ENG OIL PRESSURE
« Reply #1 on: November 20, 2019, 02:08:06 PM »
Have you checked the oil level?  How many miles on the engine?  What's the oil pressure at 1,500+ RPM?  Was there a sudden decrease in oil pressure at idle or has it been this way for some time?  Have you verified the oil pressure using a manual test gauge or are you relying on the factory dash gauge?
Logged
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Shifty

  • Junior Member
  • ***
  • Posts: 951
  • I bleed Bowtie red...
Re: ENG OIL PRESSURE
« Reply #2 on: November 20, 2019, 04:06:19 PM »
The olde small-block Chevy formula was 10 pounds per 1,000 rpm, if that means anything to ya.
Logged
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

98 C2500 ext cab longbed

Offline bedwards

  • Newbie
  • Posts: 80
  • Newbie
Re: ENG OIL PRESSURE
« Reply #3 on: November 20, 2019, 06:54:49 PM »
If your talking factory gauge, they are notoriously inaccurate.
Logged

Offline Shifty

  • Junior Member
  • ***
  • Posts: 951
  • I bleed Bowtie red...
Re: ENG OIL PRESSURE
« Reply #4 on: November 21, 2019, 08:33:48 AM »
Quote from: bedwards on November 20, 2019, 06:54:49 PM
If your talking factory gauge, they are notoriously inaccurate.
Agreed.  According to mine, I should be pushing the truck instead of driving.  :o
Logged
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

98 C2500 ext cab longbed

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2555
  • Old Goof
Re: ENG OIL PRESSURE
« Reply #5 on: November 22, 2019, 01:29:07 PM »
Are you using a multi viscousity oil, like 10-30?

Might be too light for a truck with high mileage.

Could go with a single vis oil, or move up to 20-50.

You don't hear knocking or rattle when that happens do you?
Logged
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction
Pages: [1]   Go Up
« previous next »