Low Oil Pressure
- Thread starter LarryW
- Start date
> Hi Matt
>
> Sending an oil sample to Blackstone after more miles on the existing oil will be next. Tapping into the oil filter adapter would be worth a try.
> Connecting copper tubing kits together would reach the oil filter adapter. When that is attempted at some point in the near future, could I impose
> on you, yet again, for a rough sketch of where to install the tap, please? As you said, it would not be a great risk. It will be interesting to see
> if the Autogauge oil pressure gauge would register higher oil pressure? It might even be worth running the adapter up to the local machine shop to
> have them install the tap.
>
> Thanks
> John
John,
When I am in my barn to do stuff again, I will pick an adapter and look it over so we can get it right.
I just forwarded a private message to you.
Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
>
> Sending an oil sample to Blackstone after more miles on the existing oil will be next. Tapping into the oil filter adapter would be worth a try.
> Connecting copper tubing kits together would reach the oil filter adapter. When that is attempted at some point in the near future, could I impose
> on you, yet again, for a rough sketch of where to install the tap, please? As you said, it would not be a great risk. It will be interesting to see
> if the Autogauge oil pressure gauge would register higher oil pressure? It might even be worth running the adapter up to the local machine shop to
> have them install the tap.
>
> Thanks
> John
John,
When I am in my barn to do stuff again, I will pick an adapter and look it over so we can get it right.
I just forwarded a private message to you.
Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
I have a mechanical gauge located at the tap point on the front of the engine along with the electrical sender right next to it and they both are very close on readings. If your concerned if you have 48 or 50 pounds on the gauge and there is a 2 or 3 # difference it doesn’t matter, as long as you have an indication of positive pressure say in the high 30’s to mid 40’s then you probably just fine. I have seen people here fight over 2 or 3# difference, again IT DOESN”T MATTER! Gauges are not necessary that accurate. I also have a digiPanel too, everything is close enough.
J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Above water in Midland Michigan
>
> Hi Larry
>
> It's mechanical. It's an Autometer brand. I had one like it before on an s-15 Jimmy 2.8L for several years. Seemed reliable. I'll keep you guys
> updated. Thanks for your interest.
>
> John
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Above water in Midland Michigan
>
> Hi Larry
>
> It's mechanical. It's an Autometer brand. I had one like it before on an s-15 Jimmy 2.8L for several years. Seemed reliable. I'll keep you guys
> updated. Thanks for your interest.
>
> John
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
You need less oil pressure then most people think. Back then. Factory low oil pressure dash lights came on at about 7 PSI. GM at the time. Saw 20 psi as a low normal. At speed, on the road.
I have a Digi Panel from Jim K at Applied. I will never drive a GMC without one of those panels. Because of the alarm that they have,
Bob Dunahugh
78 Royale
4 COPO Yenkos
I have a Digi Panel from Jim K at Applied. I will never drive a GMC without one of those panels. Because of the alarm that they have,
Bob Dunahugh
78 Royale
4 COPO Yenkos
Flow is as important as pressure. The oil absorbs heat from combustion as
well as friction between heavily loaded bearing surfaces, and carried away
to be exchanged into the air by oil coolers and the sides of the oil pan,
etc. Engines have to have the capacity of greater heat exchange than their
ability to create it, or very bad stuff happens rapidly. 7-10 psi is
adequate idle speed pressure, 35 - 40 psi is enough at 2000 rpm @ 40% load.
Lots of opinions abound relative to oil pressure.
Jim Hupy
Salem, Oregon
On Thu, May 21, 2020, 10:30 PM Bob Dunahugh via Gmclist <
> You need less oil pressure then most people think. Back then. Factory low
> oil pressure dash lights came on at about 7 PSI. GM at the time. Saw 20
> psi as a low normal. At speed, on the road.
> I have a Digi Panel from Jim K at Applied. I will never drive a GMC
> without one of those panels. Because of the alarm that they have,
> Bob Dunahugh
> 78 Royale
> 4 COPO Yenkos
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
well as friction between heavily loaded bearing surfaces, and carried away
to be exchanged into the air by oil coolers and the sides of the oil pan,
etc. Engines have to have the capacity of greater heat exchange than their
ability to create it, or very bad stuff happens rapidly. 7-10 psi is
adequate idle speed pressure, 35 - 40 psi is enough at 2000 rpm @ 40% load.
Lots of opinions abound relative to oil pressure.
Jim Hupy
Salem, Oregon
On Thu, May 21, 2020, 10:30 PM Bob Dunahugh via Gmclist <
> You need less oil pressure then most people think. Back then. Factory low
> oil pressure dash lights came on at about 7 PSI. GM at the time. Saw 20
> psi as a low normal. At speed, on the road.
> I have a Digi Panel from Jim K at Applied. I will never drive a GMC
> without one of those panels. Because of the alarm that they have,
> Bob Dunahugh
> 78 Royale
> 4 COPO Yenkos
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
Hi J.R.
Thanks for the input. I am at the low end of the spectrum on oil pressure. On a warm (hot) engine, I am getting a reading of 18 - 19 pounds at 55
mph; about 5 pounds at a fast idle, maybe 900 rpms. I bought a tach but have yet to install it. Sitting at a traffic signal, in gear, the pressure
drops to 2 - 3 pounds. I have gotten into the habit of putting it in neutral at a traffic signal and keeping the rpms up. Long story short, there is
no logical reason why my oil pressure should be that low. The compression is consistent on all eight cylinders. My gauge reads 170# but I've been told
my gauge must be off because a new engine only reads about 140 Point well taken, but the consistency of the pressure on all eight cylinders is what
is important, plus the fact that it runs great and has lots of power. I have no clatter of the lifters at any rpm. There is no knocking sound coming
from the engine and I have been really paying close attention. I am still trying to get around 1,000 miles on the oil so I can send a sample to
Blackstone for an analysis. Several of the great guys out here on the forum have been trying to help. The general consensus is the relief valve on the
oil pump may be stuck or partially blocked. There are a couple "tricks" I can try as soon as I get it down off the blocks, which is getting very near.
A silly problem of the wrong V-belts lengths is giving me fits at the moment. I'll be reporting my progress.
Thanks for the input. I am at the low end of the spectrum on oil pressure. On a warm (hot) engine, I am getting a reading of 18 - 19 pounds at 55
mph; about 5 pounds at a fast idle, maybe 900 rpms. I bought a tach but have yet to install it. Sitting at a traffic signal, in gear, the pressure
drops to 2 - 3 pounds. I have gotten into the habit of putting it in neutral at a traffic signal and keeping the rpms up. Long story short, there is
no logical reason why my oil pressure should be that low. The compression is consistent on all eight cylinders. My gauge reads 170# but I've been told
my gauge must be off because a new engine only reads about 140 Point well taken, but the consistency of the pressure on all eight cylinders is what
is important, plus the fact that it runs great and has lots of power. I have no clatter of the lifters at any rpm. There is no knocking sound coming
from the engine and I have been really paying close attention. I am still trying to get around 1,000 miles on the oil so I can send a sample to
Blackstone for an analysis. Several of the great guys out here on the forum have been trying to help. The general consensus is the relief valve on the
oil pump may be stuck or partially blocked. There are a couple "tricks" I can try as soon as I get it down off the blocks, which is getting very near.
A silly problem of the wrong V-belts lengths is giving me fits at the moment. I'll be reporting my progress.
