12.5-13# oil pressure @ hot idle??

jaymac

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Feb 18, 2004

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Northern Mass

Jul 27, 2006

#1

• Jul 27, 2006

• #1

I searched and saw this issue touched on, but never a definitive answer, so:
Engine starts and warms up slightly above 50 psi, and once it's hot, it will settle down to about 12.5-15 psi at idle. Lately it's been in the 80's-90's here. I run Mobil 1 5w-30, and there's 123,xxx miles on the engine, never rebuilt. It is an autometer gauge. Earlier this year, before it got hot outside, the lowest it would ever go is 20-25, using the same gauge and weight oil.
Once you touch the gas, it will go back up to 35, and will stay at 35-40 while cruising at 2000+
What do you guys think? Reason to worry? Should I just switch to 10w-30 and see what happens for the summer?
Thanks for the replies!
Jeremy

 

R

R2D2

Jul 27, 2006

#2

• Jul 27, 2006

• #2

it's fine

 

DMAN302

My mom says thanks for the pearl necklace.

Nov 8, 2003

2,120

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59

windsor, Canada

Jul 27, 2006

#3

• Jul 27, 2006

• #3

jaymac said:

I searched and saw this issue touched on, but never a definitive answer, so:
Engine starts and warms up slightly above 50 psi, and once it's hot, it will settle down to about 12.5-15 psi at idle. Lately it's been in the 80's-90's here. I run Mobil 1 5w-30, and there's 123,xxx miles on the engine, never rebuilt. It is an autometer gauge. Earlier this year, before it got hot outside, the lowest it would ever go is 20-25, using the same gauge and weight oil.
Once you touch the gas, it will go back up to 35, and will stay at 35-40 while cruising at 2000+
What do you guys think? Reason to worry? Should I just switch to 10w-30 and see what happens for the summer?
Thanks for the replies!
Jeremy

Click to expand...

Might need to look at a new pump..numbers are on the attention getting side. Other options are switch to a 10-40 or 20-50 to help out pressure situation.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Jul 27, 2006

#4

• Jul 27, 2006

• #4

Jeremy, I also wouldnt infer much until you run a thicker oil (while in the heatwave).

If it stays hot outside, I might step up to a 10W-XX (if you happen to be ready to change oil).

 

ninety15.0

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Mar 10, 2004

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Jul 27, 2006

#5

• Jul 27, 2006

• #5

I live in Charleston SC and it has been in the mid to upper 90's for the past two weeks. Im running 20-50 amsoil sythetic right now and i hold 35# at HOT idle and 45-50 at cruise. When i first got down here and i was running 5-30 i was pulling like 35# at cruise and 15-20# at hot idle. I didnt really like it and i knew i wasnt going to be beating on my car too bad while i was down here so i switched to the 20-50 for safety sake! Also what kinda of gauge are you using.

 

Mavrick

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Aug 29, 2002

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Collingwood, ON

Jul 27, 2006

#6

• Jul 27, 2006

• #6

With 5-30, mine runs around 15psi at hot idle. Cruise is 50+.

 

jaymac

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Feb 18, 2004

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Northern Mass

Jul 27, 2006

#7

• Jul 27, 2006

• #7

it's an autometer.
Today it hasn't been too bad. Not as hot, and lowest I saw it at was about 14-25... I'll consider the weight swap. I just changed oil about 1000 mile ago, but why not??

 

srothfuss

Last night I stabbed the same guy 7 times in a row

Oct 17, 2004

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Woodward Ave.

Jul 27, 2006

#8

• Jul 27, 2006

• #8

mine also ran lower numbers at hot idle. Switched to 10/30 and now I idle in the mid 20's.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

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Jul 27, 2006

#9

• Jul 27, 2006

• #9

Realistically, I dont like to see pressure quite that low (14 PSI at idle), but since it jumps up as soon as you bump the throttle, I might not sweat it. You know that you have outstanding protection/clinging with the M1 oil.............

If you do change it, pour it back into the jug and use it again this winter.

 

91lxttrim

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Mar 7, 2006

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AZ

Jul 27, 2006

#10

• Jul 27, 2006

• #10

I always thought anything below 20 psi at idle was bad news. I have an oil pressure warning light from Auto Meter and the sending unit for the light is 18psi. So it will go off if the pressure gets below 18# which means shut down. Is this true or can these engines run at lower pressure?

FYI mine idles at 22-25# hot with a/c, and cruise 2000 rpm is about 60#.

 

srothfuss

Last night I stabbed the same guy 7 times in a row

Oct 17, 2004

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Woodward Ave.

Jul 27, 2006

#11

• Jul 27, 2006

• #11

Shoot, a Chevy can idle with almost 0PSI

 

jaymac

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Feb 18, 2004

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Northern Mass

Jul 27, 2006

#12

• Jul 27, 2006

• #12

HISSIN50 said:

If you do change it, pour it back into the jug and use it again this winter.

Click to expand...

Hell yeah! (I think... )

 

R

R2D2

Jul 27, 2006

#13

• Jul 27, 2006

• #13

low oil pressure is nothing more than 2-3 things, bearing clearances are opening up, pump is bleeding some pressure off due to rotor clearances or the freak leaks at the pickup. You can run all day long at 10psi per 1000 rpm, regardless if that formula is from the 60-70's, it still holds true today regardless of the oil being used. The thread starters motor is fine, your gonna lose bearing clearance, no two ways around it.

 

mattmcdan

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Apr 19, 2006

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Okeechobee, Florida

Jul 27, 2006

#14

• Jul 27, 2006

• #14

I got 5psi hot with 20w50 with my stock 150K mile 1986 engine, I ran it for 2 years that way, and it would still run If I had not changed it out. If you don't beat on it, it will last forever.

 

jaymac

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Feb 18, 2004

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Northern Mass

Jul 28, 2006

#15

• Jul 28, 2006

• #15

sbftech said:

The thread starters motor is fine,

Click to expand...

That's reassuring; thanks! I checked out your website by the way, looks like good quality stuff. I'll keep it in mind for the future!
Thanks!
Jeremy