Oil pressure fluctuating - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

CorvetteC6 · 06-28-2023, 07:07 AM

L99 stock, AFM disabled with Range.

Everything was fine, hot idle 23-25 psi. Today at a traffic light oil pressure dropped to almost zero. 30 psi while driving and floats a little. When car stops, pressure droops to 15 psi and suddenly can drop to 0 and then rise. Red oil pressure light does not light up.

As far as I understand, a mechanical pump either works and gives pressure or not.

Could it be the pressure sensor on the Valley Cover?
Could it be Pressure Relief Valve inside oil pan?

Oil pump replaced to Melling M365 with oil pickup rings.
Oil pickup tube mode not installed.

1JEWLDSSRS · 06-28-2023, 09:23 AM

Another possibility that I have read about on here is the screen under the oil pressure switch getting clogged with debris. From what I understand only the L99 engines have this, and I see you are an auto.

gtstorey · 06-28-2023, 10:12 AM

My advice is never assume that it's a sensor or a screen on a sensor without confirming actual pressure with a secondary device.

CorvetteC6 · 06-29-2023, 12:14 AM

Quote:

Originally Posted by gtstorey

My advice is never assume that it's a sensor or a screen on a sensor without confirming actual pressure with a secondary device.

Is it possible for the pump to give variable pressure at idle?

The pressure changes from zero to 15, then to 25 psi and back down. And sometimes it doesn't fluctuate at all

morepowerjoe · 06-29-2023, 03:10 AM

Let me make sure I'm understanding this correctly. So you replaced your l99 oil pump with a M365 and now have the oil fluctuations?

CorvetteC6 · 06-29-2023, 06:06 AM

Most likely found the cause. The problem was a pierced through pressure sensor. I took it off and it was covered in oil from the inside, including the connector. In addition, the resistance did not match with the new sensor.

gtstorey · 06-29-2023, 10:37 AM

Quote:

Originally Posted by CorvetteC6

Is it possible for the pump to give variable pressure at idle?

The pressure changes from zero to 15, then to 25 psi and back down. And sometimes it doesn't fluctuate at all

If one of the relief valves is having a problem, maybe. If the pickup tube or o-ring is damaged, maybe.

Moto-Mojo · 06-29-2023, 01:54 PM

The oil pressure gauge is mostly blocked from my view with the same instrument cluster. I'll never know until it's too late if mine ever fails.

1JEWLDSSRS · 06-29-2023, 08:14 PM

Quote:

Originally Posted by Moto-Mojo

The oil pressure gauge is mostly blocked from my view with the same instrument cluster. I'll never know until it's too late if mine ever fails.

And that's exactly one of the reasons I have the Aeroforce Dual pillar gauge pod in my Camaro, I monitor battery, oil pressure, trans temp and engine temp showing at all times, then I can scroll through the parameters and check all sorts of other items I selected like AFR, injector duty, IAT's and more. Nice setup.

06-28-2023, 07:07 AM	#1
CorvetteC6 Drives: 2011 Chevy Camaro SS Auto Join Date: Dec 2022 Location: Geneva, Swiss Posts: 24	Oil pressure fluctuating L99 stock, AFM disabled with Range. Everything was fine, hot idle 23-25 psi. Today at a traffic light oil pressure dropped to almost zero. 30 psi while driving and floats a little. When car stops, pressure droops to 15 psi and suddenly can drop to 0 and then rise. Red oil pressure light does not light up. As far as I understand, a mechanical pump either works and gives pressure or not. Could it be the pressure sensor on the Valley Cover? Could it be Pressure Relief Valve inside oil pan? Oil pump replaced to Melling M365 with oil pickup rings. Oil pickup tube mode not installed. Attached Images

06-28-2023, 09:23 AM	#2
1JEWLDSSRS Drives: 2011 SS-RS Join Date: May 2011 Location: FLORIDA Posts: 13,692	Another possibility that I have read about on here is the screen under the oil pressure switch getting clogged with debris. From what I understand only the L99 engines have this, and I see you are an auto. __________________ TSP STAGE 3 CAM,231/246 @112 LSA 614/641 LIFT, CIRCLE D 5C-4200-4500 CONVERTER,LOD INTAKE.CORSA EXHAUST. DSS 1 PC DS. PEGASUS SOLID CRADLE MOUNTS. 486RWHP/475RWTQ.LOTS MORE.

06-29-2023, 03:10 AM	#5
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,230	Let me make sure I'm understanding this correctly. So you replaced your l99 oil pump with a M365 and now have the oil fluctuations? __________________ DSS Pistons, Eagle ESP L19 Rods, ARP Head and Main Studs, TSP PRC CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Racing Lifters, CHE Trunnions, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP Longtubes, ZL1 Fuel Pump, Mishimoto Radiator and Oil Cooler, 3600 Circle D Converter, Tru Cool 40k Tranny Cooler, Fluid Dynamics Balancer, EBC 3GD Rotors with EBC Bluestuff NDX Pads, Bilstein B6 Shocks / Struts with Eibach ZL1 Drop Springs Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

06-29-2023, 06:06 AM	#6
CorvetteC6 Drives: 2011 Chevy Camaro SS Auto Join Date: Dec 2022 Location: Geneva, Swiss Posts: 24	Most likely found the cause. The problem was a pierced through pressure sensor. I took it off and it was covered in oil from the inside, including the connector. In addition, the resistance did not match with the new sensor. Attached Images

06-29-2023, 01:54 PM	#8
Moto-Mojo Fast Cars and Old Guitars Drives: 2015 2SS RS (L99, baby!) Join Date: Apr 2012 Location: N. CA Posts: 4,198	The oil pressure gauge is mostly blocked from my view with the same instrument cluster. I'll never know until it's too late if mine ever fails. __________________ “I don’t want to belong to any club that would have me as a member.” - Groucho Marx

06-28-2023, 10:12 AM	#3
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,433	My advice is never assume that it's a sensor or a screen on a sensor without confirming actual pressure with a secondary device.