Strange Oil Pressure Question
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Joined: Apr 2017
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Strange Oil Pressure Question Hi, new member here with an oil pressure conundrum I could really use some help with.
2007 Yukon with the 5.3, 166K miles.
In-dash gauge started dropping to 0 at idle after reaching normal operating temp. Ran in to this before, replaced the sender with one from autozone (I know, I know) and eventually replaced the oil pickup tube o-ring and everything was fine for 6+ months. Now it's back.
Attached an "Oil Port adapter"( ) replacing the cooler bypass plate near the oil filter with one that has a 1/8" NPT fitting. Connected mechanical gauge, that reads fine. 30psi at startup, 24-30 at idle once warmed up, 30 at 1500RPM cruise. These seem a little low to me, but reading multiple threads here and elsewhere they don't seem that out of line, but feel free to correct me if I'm wrong.
Replaced the sender and filter screen with GM parts, still dropping to 0 once warmed up and driving.
Removed the sender and attached a second mechanical gauge. Mechanical gauge verifies what the dash gauge was doing, dropping to 0 psi once it's warmed up and driving.
Poured Seafoam down the mechanical gauge line on the top sender port followed by blasts of air from my compressor. Put maybe 1/3 of a bottle in, reconnected the gauge and nothing has changed.
I'm really confused by these symptoms. Is the top of the engine starving for oil and if so, why? It would seem that if the path was that obstructed the pressure on the bottom would skyrocket? No sign of debris in the oil or any other issues.
As a final test I'm going to remove the screen on the top sender port, but this seems unlikely to change anything. If nothing changes what is my next step? I'm thinking a higher flow oil pump (due to mileage) and a new O-ring. Any other thoughts? Heavier oil than factory recommended?
Thanks in advance for any help!
2007 Yukon with the 5.3, 166K miles.
In-dash gauge started dropping to 0 at idle after reaching normal operating temp. Ran in to this before, replaced the sender with one from autozone (I know, I know) and eventually replaced the oil pickup tube o-ring and everything was fine for 6+ months. Now it's back.
Attached an "Oil Port adapter"( ) replacing the cooler bypass plate near the oil filter with one that has a 1/8" NPT fitting. Connected mechanical gauge, that reads fine. 30psi at startup, 24-30 at idle once warmed up, 30 at 1500RPM cruise. These seem a little low to me, but reading multiple threads here and elsewhere they don't seem that out of line, but feel free to correct me if I'm wrong.
Replaced the sender and filter screen with GM parts, still dropping to 0 once warmed up and driving.
Removed the sender and attached a second mechanical gauge. Mechanical gauge verifies what the dash gauge was doing, dropping to 0 psi once it's warmed up and driving.
Poured Seafoam down the mechanical gauge line on the top sender port followed by blasts of air from my compressor. Put maybe 1/3 of a bottle in, reconnected the gauge and nothing has changed.
I'm really confused by these symptoms. Is the top of the engine starving for oil and if so, why? It would seem that if the path was that obstructed the pressure on the bottom would skyrocket? No sign of debris in the oil or any other issues.
As a final test I'm going to remove the screen on the top sender port, but this seems unlikely to change anything. If nothing changes what is my next step? I'm thinking a higher flow oil pump (due to mileage) and a new O-ring. Any other thoughts? Heavier oil than factory recommended?
Thanks in advance for any help!
Staging Lane
Joined: Mar 2016
Posts: 51
Likes: 1
Hi, new member here with an oil pressure conundrum I could really use some help with.
2007 Yukon with the 5.3, 166K miles.
In-dash gauge started dropping to 0 at idle after reaching normal operating temp. Ran in to this before, replaced the sender with one from autozone (I know, I know) and eventually replaced the oil pickup tube o-ring and everything was fine for 6+ months. Now it's back.
Attached an "Oil Port adapter"(https://www.amazon.com/gp/product/B00LV4IJSY) replacing the cooler bypass plate near the oil filter with one that has a 1/8" NPT fitting. Connected mechanical gauge, that reads fine. 30psi at startup, 24-30 at idle once warmed up, 30 at 1500RPM cruise. These seem a little low to me, but reading multiple threads here and elsewhere they don't seem that out of line, but feel free to correct me if I'm wrong.
Replaced the sender and filter screen with GM parts, still dropping to 0 once warmed up and driving.
Removed the sender and attached a second mechanical gauge. Mechanical gauge verifies what the dash gauge was doing, dropping to 0 psi once it's warmed up and driving.
Poured Seafoam down the mechanical gauge line on the top sender port followed by blasts of air from my compressor. Put maybe 1/3 of a bottle in, reconnected the gauge and nothing has changed.
I'm really confused by these symptoms. Is the top of the engine starving for oil and if so, why? It would seem that if the path was that obstructed the pressure on the bottom would skyrocket? No sign of debris in the oil or any other issues.
As a final test I'm going to remove the screen on the top sender port, but this seems unlikely to change anything. If nothing changes what is my next step? I'm thinking a higher flow oil pump (due to mileage) and a new O-ring. Any other thoughts? Heavier oil than factory recommended?
Thanks in advance for any help!
2007 Yukon with the 5.3, 166K miles.
In-dash gauge started dropping to 0 at idle after reaching normal operating temp. Ran in to this before, replaced the sender with one from autozone (I know, I know) and eventually replaced the oil pickup tube o-ring and everything was fine for 6+ months. Now it's back.
Attached an "Oil Port adapter"(https://www.amazon.com/gp/product/B00LV4IJSY) replacing the cooler bypass plate near the oil filter with one that has a 1/8" NPT fitting. Connected mechanical gauge, that reads fine. 30psi at startup, 24-30 at idle once warmed up, 30 at 1500RPM cruise. These seem a little low to me, but reading multiple threads here and elsewhere they don't seem that out of line, but feel free to correct me if I'm wrong.
Replaced the sender and filter screen with GM parts, still dropping to 0 once warmed up and driving.
Removed the sender and attached a second mechanical gauge. Mechanical gauge verifies what the dash gauge was doing, dropping to 0 psi once it's warmed up and driving.
Poured Seafoam down the mechanical gauge line on the top sender port followed by blasts of air from my compressor. Put maybe 1/3 of a bottle in, reconnected the gauge and nothing has changed.
I'm really confused by these symptoms. Is the top of the engine starving for oil and if so, why? It would seem that if the path was that obstructed the pressure on the bottom would skyrocket? No sign of debris in the oil or any other issues.
As a final test I'm going to remove the screen on the top sender port, but this seems unlikely to change anything. If nothing changes what is my next step? I'm thinking a higher flow oil pump (due to mileage) and a new O-ring. Any other thoughts? Heavier oil than factory recommended?
Thanks in advance for any help!
