Zero oil pressure - Debug thread
Tech Contributor
Joined: Dec 1999
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The ONLY two things that I have seen cause a ONE DAY GOOD to the next day BAD oil pressure reading is:
-The Pump "INTERNAL" Relief Valve gets stuck in the fully OPEN position.
- The O Ring between the pump and pick up tube fails (this usually happens as a result of poor reassembly)
Oil Pump vs Pick Up Tube CUT AWAY:
BC
-The Pump "INTERNAL" Relief Valve gets stuck in the fully OPEN position.
- The O Ring between the pump and pick up tube fails (this usually happens as a result of poor reassembly)
Oil Pump vs Pick Up Tube CUT AWAY:
BC
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 479
From: OK
[QUOTE=Bill Curlee;1589508069]The ONLY two things that I have seen cause a ONE DAY GOOD to the next day BAD oil pressure reading is:
-The Pump "INTERNAL" Relief Valve gets stuck in the fully OPEN position.
- The O Ring between the pump and pick up tube fails (this usually happens as a result of poor reassembly)
Is there any way to tell when either of these two failures occur, besides taking the pan or pans off and inspecting them?
-The Pump "INTERNAL" Relief Valve gets stuck in the fully OPEN position.
- The O Ring between the pump and pick up tube fails (this usually happens as a result of poor reassembly)
Is there any way to tell when either of these two failures occur, besides taking the pan or pans off and inspecting them?
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2020 Corvette of the Year Finalist (performance mods)
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shouldn't have to pull the pan to inspect the oil pump/pickup tube o-ring... you will have to move the steering rack out of the way and remove the balancer and front cover to gain access to the oil pump... you can remove the pickup tube from the pump and inspect the o-ring without having to lower the pan just be careful not to drop the bolt... for whatever reason there are 2 bolt holes in the pickup tube where it bolts to the oil pump but only one is used, vettes use the front hole and for whatever reason the f-body uses the rear hole which makes an oil pump swap a little more difficult
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 479
From: OK
shouldn't have to pull the pan to inspect the oil pump/pickup tube o-ring... you will have to move the steering rack out of the way and remove the balancer and front cover to gain access to the oil pump... you can remove the pickup tube from the pump and inspect the o-ring without having to lower the pan just be careful not to drop the bolt... for whatever reason there are 2 bolt holes in the pickup tube where it bolts to the oil pump but only one is used, vettes use the front hole and for whatever reason the f-body uses the rear hole which makes an oil pump swap a little more difficult
So, is that the ONLY way to tell if that is the problem as Bill described... or is there some other way/symptom to diagnose those two failures?
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,823
Likes: 42
From: East Aurora NY
Let me make sure I'm getting this straight...
Your car is running fine no codes, normal operating pressures and temps... then all the sudden, BAM you have ZERO oil pressure.
First off then, I wouldn't have suspected oil pump... I would think that would have been a gradual or drop in pressure, not just BAM to Zero...
Unless there was a hole knocked in your oil pan, oil line broke, something to cause a dump of all of your oil...
My first thought would be OPS, second would have been gauges... wiring.
Of all the threads I've read so far, this one intrigues me more than any others just because it doesn't make sense to me...that the oil pump was the culprit. I'm looking forward to you getting your issue fixed and hoping you have no engine damage....
Your car is running fine no codes, normal operating pressures and temps... then all the sudden, BAM you have ZERO oil pressure.
First off then, I wouldn't have suspected oil pump... I would think that would have been a gradual or drop in pressure, not just BAM to Zero...
Unless there was a hole knocked in your oil pan, oil line broke, something to cause a dump of all of your oil...
My first thought would be OPS, second would have been gauges... wiring.
Of all the threads I've read so far, this one intrigues me more than any others just because it doesn't make sense to me...that the oil pump was the culprit. I'm looking forward to you getting your issue fixed and hoping you have no engine damage....
Previous to changing the pump, I did replace the OPS and tested the wiring to the best of my abilities. Also I changed the oil and filter too.
Going to be placing a mechanical gauge on it tonight and seeing if I have pressure. I hope I do, so I don't have to tear it down again. Then its back to the sensor, wiring, etc.
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,823
Likes: 42
From: East Aurora NY
The ONLY two things that I have seen cause a ONE DAY GOOD to the next day BAD oil pressure reading is:
-The Pump "INTERNAL" Relief Valve gets stuck in the fully OPEN position.
- The O Ring between the pump and pick up tube fails (this usually happens as a result of poor reassembly)
Oil Pump vs Pick Up Tube CUT AWAY:
BC
-The Pump "INTERNAL" Relief Valve gets stuck in the fully OPEN position.
- The O Ring between the pump and pick up tube fails (this usually happens as a result of poor reassembly)
Oil Pump vs Pick Up Tube CUT AWAY:
BC
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 243
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
In your OP, when you said you tested the wiring, did that include a continuity check for all three wires between the EOP connector and the PCM?
The reason I'm thinking this may still be electrical as opposed to strictly mechanical, is that in your OP you said you experienced zero oil pressure indications, and then you replaced the oil pump (along with the other items mentioned) and still experienced the same thing.
The reason I'm thinking this may still be electrical as opposed to strictly mechanical, is that in your OP you said you experienced zero oil pressure indications, and then you replaced the oil pump (along with the other items mentioned) and still experienced the same thing.
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Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,823
Likes: 42
From: East Aurora NY
Another CF member stopped over today and helped me find the root cause. We tested the pressure using a mechanical gauge, still zero. Then we took the lower batwing pan off, and to our surprise it was clogged. It was a mixture of what looked to be a "fiberish" material and some parts orange gasket, but mainly "fiberish". No idea what is was, but once cleared the car had good oil pressure
Racer
Joined: May 2014
Posts: 356
Likes: 29
From: Orchard Park NY
Another CF member stopped over today and helped me find the root cause. We tested the pressure using a mechanical gauge, still zero. Then we took the lower batwing pan off, and to our surprise it was clogged. It was a mixture of what looked to be a "fiberish" material and some parts orange gasket, but mainly "fiberish". No idea what is was, but once cleared the car had good oil pressure
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 479
From: OK
Did your air filter or oil filter come apart? Can you have the fiber analyzed?
Well, glad you found what the issue was and got it removed...my concern would be where the hell did it come from and will it do it again...
Thank you for posting your findings!
Well, glad you found what the issue was and got it removed...my concern would be where the hell did it come from and will it do it again...
Thank you for posting your findings!
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,823
Likes: 42
From: East Aurora NY
Pending my oil pressure stays rock solid
I'll be posting updates in my ECS Blower Build thread (Forced Induction Section).
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,823
Likes: 42
From: East Aurora NY
and the dollar tree is bare because of the blower build haha it really adds up fast, and then you are in too deep to stop lol
Tech Contributor
Joined: Dec 1999
Posts: 32,910
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
WINNER!!!!
I would not have suspected a clogged strainer in 100 years.. Only because normally, CRAP like that doesn't get into an engine under normal conditions or when you have the engine disassembled.
SOMEBODY,,,,,,,,,,,,
,,,,,,,,,,,, left a shop towel in the unassembled engine... 
Last edited by Bill Curlee; Apr 28, 2015 at 10:29 AM.
Thread Starter
Drifting
Joined: Mar 2011
Posts: 1,823
Likes: 42
From: East Aurora NY
WINNER!!!!
I would not have suspected a clogged strainer in 100 years.. Only because normally, CRAP like that doesn't get into an engine under normal conditions or when you have the engine disassembled.
SOMEBODY,,,,,,,,,,,,,,,,,,,,,,,, left a shop towel in the unassembled engine...
I would not have suspected a clogged strainer in 100 years.. Only because normally, CRAP like that doesn't get into an engine under normal conditions or when you have the engine disassembled.
SOMEBODY,,,,,,,,,,,,
,,,,,,,,,,,, left a shop towel in the unassembled engine...
Acct Suspended APR 2026 by request
Joined: Dec 2010
Posts: 10,367
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2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
I would not have suspected a clogged strainer in 100 years.. Only because normally, CRAP like that doesn't get into an engine under normal conditions or when you have the engine disassembled.
SOMEBODY,,,,,,,,,,,,,,,,,,,,,,,, left a shop towel in the unassembled engine...
SOMEBODY,,,,,,,,,,,,
,,,,,,,,,,,, left a shop towel in the unassembled engine...
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 479
From: OK
[QUOTE=Bill Curlee;1589508069]The ONLY two things that I have seen cause a ONE DAY GOOD to the next day BAD oil pressure reading is:
-The Pump "INTERNAL" Relief Valve gets stuck in the fully OPEN position.
- The O Ring between the pump and pick up tube fails (this usually happens as a result of poor reassembly)
Need to add... some Knucklehead leaves a rag in the oil pan
-The Pump "INTERNAL" Relief Valve gets stuck in the fully OPEN position.
- The O Ring between the pump and pick up tube fails (this usually happens as a result of poor reassembly)
Need to add... some Knucklehead leaves a rag in the oil pan
Last edited by 73Corvette; Apr 28, 2015 at 07:53 PM.