2012 gmc sierra oil consumption

[cquint]

I recently noticed the oil pressure would goto 40 on a cold start then slowly goto 20. When accelerating it would barely go up from 20. I checked the oil after I let it sit and it was about 1-2 quarts low. Its been about 950 miles since the last oil change. I dont know what the normal oil pressure should be but before this at a hot idle it sits about 20 and goes to 40 when accelerating.

 

Truck has about 84k miles.

[Dustoff87]

Which motor do you have?

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[cquint]

Just now, Dustoff87 said:

Which motor do you have?

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5.3

[Dustoff87]

On the top of the motor on the backside is your oil sending unit. If you remove the sending unit and stick a 3" drywall screw down into it you'll feel like resistance, just push through that and then pull it up. You will pull out a small debris screen. Most likely that screen is clogged and needs replacement. It's about a $7 part but the sending unit is a pain to access and the wiring clip can be a pain in the dick to remove. I just snapped off the wiring harness clip to make it easier for next time.

 

 

 

 

 

 

[Dustoff87]

Hopefully that will solve your pressure problem however, the oil consumption problem is usually tied to the Active Fuel Management. I disabled the AFM and the oil consumption problem was solved

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[cquint]

4 minutes ago, Dustoff87 said:

On the top of the motor on the backside is your oil sending unit. If you remove the sending unit and stick a 3" drywall screw down into it you'll feel like resistance, just push through that and then pull it up. You will pull out a small debris screen. Most likely that screen is clogged and needs replacement. It's about a $7 part but the sending unit is a pain to access and the wiring clip can be a pain in the dick to remove. I just snapped off the wiring harness clip to make it easier for next time.

 

 

 

 

 

 

I have replaced the screen and sending unit about 2 years ago. Do these need to be replaced that often?

[Dustoff87]

I've been replacing mine about every 2 years.

 

[cquint]

Just now, Dustoff87 said:

I've been replacing mine about every 2 years.

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Okay, thanks.

[Sharpz]

7 hours ago, cquint said:

I have replaced the screen and sending unit about 2 years ago. Do these need to be replaced that often?

In your case, since you are experiencing oil pressure issues, it would be one of the cheapest attempts at a fix.   I would also change the oil, and filter at the same time even though you are only at 1000 mark. 

[swathdiver]

On 3/29/2021 at 10:56 PM, cquint said:

I recently noticed the oil pressure would goto 40 on a cold start then slowly goto 20. When accelerating it would barely go up from 20. I checked the oil after I let it sit and it was about 1-2 quarts low. Its been about 950 miles since the last oil change. I dont know what the normal oil pressure should be but before this at a hot idle it sits about 20 and goes to 40 when accelerating.

 

Truck has about 84k miles.

What kind of oil and filter are you using?  How often do you change it?

 

Which 5.3 engine, the LMG or the LC9?  The LC9 runs at a lower oil pressure, just below 40, but pumps 1/3 more volume per revolution as it has an aluminum block.

[cquint]

15 hours ago, swathdiver said:

What kind of oil and filter are you using?  How often do you change it?

 

Which 5.3 engine, the LMG or the LC9?  The LC9 runs at a lower oil pressure, just below 40, but pumps 1/3 more volume per revolution as it has an aluminum block.

I was using penzoil platinum, The last change I did I switched it up to Mobil 1 to see if there was a difference . Its done every 3k with acdelco filter.  Its a LC9.

[swathdiver]

7 hours ago, cquint said:

I was using penzoil platinum, The last change I did I switched it up to Mobil 1 to see if there was a difference . Its done every 3k with acdelco filter.  Its a LC9.

Ok, Calvin.  Mine is not much different.  Once warmed up, she runs just shy of 40 psi while driving and in the mid to high 20s while stopped at a light.  Both our LC9 and L9H run this way.  I gained 2-3 psi when I switched off of Mobil 1 EP and ACDelco oil filters and went with K&N long filter with the nut on the end.  Aluminum engines are more loose, yours just a little more so it seems.  I also switched to ACDelco oil, no more rattle on start up and gained a 1/4 MPG in fuel efficiency on the LC9.  Mobil 1 is not what it once was.