High oil pressure when cold

[2017HD]

New truck only 150 miles - noticed this AM that the oil pressure gauge is almost pegged at 120 until engine temp rises. Is this going to hurt anything? I did not notice this until this morning -picked up the truck on Fri.

[Peterd]

New truck only 150 miles - noticed this AM that the oil pressure gauge is almost pegged at 120 until engine temp rises. Is this going to hurt anything? I did not notice this until this morning -picked up the truck on Fri.

Have the same issue. My 2015 showed 70+ cold and 60 from 40mph up. The 2017 pegs the guage cold runs up,to 60mph at 30+ and about 50+ over 60 mph. 30 to 120 just seems wrong. Have requested dealer check sending unit when the other items are addressed.

 

Just turned 1,000 miles and am experiencing most of the quirks others have reported. A bit disappointed as the 2015 went 100'000 with only the antenna gasket leak

[1st diesel truck]

I noticed mine seemed high too but I did just locate a TSB on another GM forum that says very high oil PSI while cold is normal and not to be concerned about it. The quote below is a copy and paste of that posted TSB which covers Duramax 2017+ L5P engine models.

 

For other similar TSB's on the L5P engine model, search online ( L5p bulletins, recalls and updated calibrations )

 

 

 

 

#17-NA-051: High Oil Pressure during Initial Start of Vehicle - (Feb 23, 2017)
Subject: High Oil Pressure during Initial Start of Vehicle


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Brand:
Model:
Model Year:
VIN:
Engine:
Transmission:

from
to
from
to

Chevrolet
Silverado
2017
2018
L5P
All

GMC
Sierra
2017
2018
L5P
All


Involved Region or Country
North America and Israel

Additional Options (RPOs)
Equipped with Diesel 6.6L Engine (RPO L5P)

Condition
Some customers may comment on high oil pressure or that the oil pressure is "pegged" high during the initial start up of the vehicle.

Cause
When first starting the engine with cold oil, the oil pressure can be up to 100 psi or 690 kPa (full range of oil pressure gauge) at idle conditions. This is normal with cold oil and internal relief valves in the engine will be active. As the engine oil temperature rises, the idle oil pressure will reduce.

Correction
This is considered a normal condition and no repairs should be performed.


Parts Information
No parts should be replaced for this condition.

Customer Information
Please communicate to the customer this condition is a normal characteristic of their vehicle. It will not impact the designed performance or reliability of the vehicle. Please share this information with the customer, including a copy of this bulletin.

Version
1

Modified

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

[redwngr]

I wonder if the sensor location is the same part of the oil circuit as on the LML?

[SMiller]

Old big blocks would peg the guage when cold, just let it warm up a little and drive easy.

[brclark82]

Glad I found this info, when my engine is "cold" (heat index today is 110 so I say cold as in hasn't been running) the pressure spikes to max with pretty much any acceleration and then down below it's normal 60 or so to around 40 on idle...certainly scared me at first

[redwngr]

I wonder if the sensor location is the same part of the oil circuit as on the LML?

My LML also showed much higher than normal oil pressure when cold. Got in the habit of driving it easy til it warmed up.

[SMiller]

My LML also showed much higher than normal oil pressure when cold. Got in the habit of driving it easy til it warmed up.

That is a damn good habit to get into regardless. I cringe when I see someone fire up a engine, throw it in gear and blast a way, we (most) are not responding to fires...

[Cowpie]

On 7/11/2017 at 9:53 PM, SMiller said:

Old big blocks would peg the guage when cold, just let it warm up a little and drive easy.

Exactly.  Oil pressure is a reflection of resistance to flow.  Cold oil takes more pressure to get it moving thru the passages until engine and oil warm up. Been that way since the dawn of the internal combustion engine.    Like has been stated, don't try doing 1/4 mile runs with a cold engine.  Just take it easy first thing.  One could let the engine idle for quite a while and warm up, but it will warm up faster under moderate driving.  Another technique, that I like to use, is a oil pan warmer.  Doesn't take much power. Plug it in when the truck is sitting and your engine will have nice warm oil flowing thru it first thing in the morning.  

[redwngr]

Oil pressure measurement is also dependent on the location that is chosen to measure the pressure.

 

The further from the pump outlet, the lower the pressure that will be measured. 

 

 

On the 6.6L, in below freezing temps, an few minutes on 'elevated idle' does a surprisingly good job of doing it's intended job of warming both the engine and the transmission. (and the bonus is it will automatically engage when remote started).  

 

(this is different than the optional fast idle (high idle) that engages with the cruise buttons - is which increases engine speed but is not designed to create heat)