Oil pressure . What’s normal ?
December 17th, 2022, 02:09 PM
#1
The Olds
Thread Starter
Join Date: Aug 2022
Posts: 69
Oil pressure . What’s normal ?
68 olds 455 all stock 44,000 miles . My question is are these numbers normal and what kind of picture does this paint ?
Running Rotella t4 15w-40 . Outside temp is 40 F
Operating temp is reading 190 F
Jegs gauge reads about 50-65 lbs cold start.
40-50 mph at operating temp it’s reading 25 psi
idle at operating temp is somewhere around 7-10 psi would be my guess
problem is the intervals on the gauge don’t really read that low but the needle is not sitting on the peg of the gauge so I know there’s some pressure.
Running Rotella t4 15w-40 . Outside temp is 40 F
Operating temp is reading 190 F
Jegs gauge reads about 50-65 lbs cold start.
40-50 mph at operating temp it’s reading 25 psi
idle at operating temp is somewhere around 7-10 psi would be my guess
problem is the intervals on the gauge don’t really read that low but the needle is not sitting on the peg of the gauge so I know there’s some pressure.
December 17th, 2022, 08:29 PM
#4
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Join Date: Jan 2010
Location: central Indiana
Posts: 5,401
Put a different gauge on it to rule out gauge inaccuracy.
If the 2nd gauge confirms the numbers, next time you change the oil cut open the filter with tin snips. Look inside the pleats for copper/brass debris. If you have bearing issues, that’s where you will see it.
Has the timing chain ever been replaced? If not, you can almost guarantee most of the nylon has broken off of the cam gear and is now on the oil pump pickup. The oil pump is almost certainly restricted, causing oil starvation and bearing wear.
If it’s not making any noise, you might be able to drop the oil pan and replace the bearings. Personally, I’d run it until there are more serious problems. It might run along time.
If the 2nd gauge confirms the numbers, next time you change the oil cut open the filter with tin snips. Look inside the pleats for copper/brass debris. If you have bearing issues, that’s where you will see it.
Has the timing chain ever been replaced? If not, you can almost guarantee most of the nylon has broken off of the cam gear and is now on the oil pump pickup. The oil pump is almost certainly restricted, causing oil starvation and bearing wear.
If it’s not making any noise, you might be able to drop the oil pan and replace the bearings. Personally, I’d run it until there are more serious problems. It might run along time.
December 18th, 2022, 06:49 AM
#5
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Join Date: Jun 2009
Location: Aledo, Texas
Posts: 2,482
December 18th, 2022, 08:32 AM
#6
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Join Date: Apr 2021
Posts: 33
I had similar numbers in my '69 that had 115k on it. The hot idle numbers were concerning.
I decided on a rebuild to be safe. Nothing notable on the tear down other than expected wear and age.
My rebuild included restrictors in the mains, restrictive push rods and a high volume oil pump.
My oil pressure is now above 60 under all conditions.
I decided on a rebuild to be safe. Nothing notable on the tear down other than expected wear and age.
My rebuild included restrictors in the mains, restrictive push rods and a high volume oil pump.
My oil pressure is now above 60 under all conditions.
January 8th, 2023, 11:24 AM
#7
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Join Date: Nov 2020
Location: Washington State
Posts: 421
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