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Discussion Starter · #1 ·
Freaked me out today oil pressure went down to zero on gauge. Check gauges light lit up. Then it goes to Full other side at 80 psi. Pulled over checked oil level, was ok. Im thinking possible oil pressure sending unit, any body know where thats located. Anybody have that issue before? Thanks
 

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Discussion Starter · #3 ·
Best to check what an obd scanner or logging tool shows. Then you can determine if it’s a sensor or the dash motor
Yeah I guess if the scanner has the oil pressure parameter and if gauge starts to act up and oil pressure on scanner still shows good it would be the gauge. I guess it wouldnt be to expensive to just switch the oil pressure sensor which I found to be near the oil filter. Unplug the sensor and see if oil is coming thru it into connector. Im not assuming its the oil pump because no knocking or lifter ticking was occuring. Thanks for idea and reply
 

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It's on the back of the block on top under the intake manifold. You can reach it from the drivers side. A few months ago my gauge pegged 0psi I removed the sender put a mechanical gauge in pressure was good, replaced sender fixed.

Sent from my SM-G991U using Tapatalk
 

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Discussion Starter · #5 ·
It's on the back of the block on top under the intake manifold. You can reach it from the drivers side. A few months ago my gauge pegged 0psi I removed the sender put a mechanical gauge in pressure was good, replaced sender fixed.

Sent from my SM-G991U using Tapatalk
Yeah thanks, I jacked up the truck at work today, Im a diesel mechanic. Looking under by oil filter,etc. I finally googled it and yeah found it was on top at back of manifold. Changed the pressure switch which was ridiculously priced at like 67 dollars. Started it up and let idle and stayed at zero psi. Didnt want to take a chance reving it up. So I was thinking wire repair now probably. So long story short was going to go home at lunch, two minutes from work, and switch cars but it shot up to 40 psi and is working fine now. No oil leak thru the sensor. Maybe just me tweaking the wires to unplug and replug fixed it. Or actual pressure switch bad. Will know soon enough if it happens again. Your everywhere civteck. Was thinking about other comment. Not like temp switch where you have two sensors sometimes, one for computer and one for gauge. So dont know if scan tool would of helped me by reading oil pressure even if it could. Three wire oil sensor. I was hoping low oil pressure sensor reading wouldnt shut me down. Obviously I wasnt driving long miles but any driving could of possibly ate my bearings. Well working fine for now but freaked me out. Thanks guys.
 

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Freaked me out today oil pressure went down to zero on gauge. Check gauges light lit up. Then it goes to Full other side at 80 psi. Pulled over checked oil level, was ok. Im thinking possible oil pressure sending unit, any body know where thats located. Anybody have that issue before? Thanks
That's the screen underneath the oil pressure gadge. You can pull it out with a hook tool, they are about $8. It will be plugged, don't run it when it's plugged. put engine cleaner in, change the oil and screen.
 

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Freaked me out today oil pressure went down to zero on gauge. Check gauges light lit up. Then it goes to Full other side at 80 psi. Pulled over checked oil level, was ok. Im thinking possible oil pressure sending unit, any body know where thats located. Anybody have that issue before? Thanks
Oil pressure sensor! Possible spun bearing
Dorman part number 926-040
Happened to me, punt new sensor in. Was normal for about 20 minutes. Then same thing happened.
changed my oil, cut the filter open and chunks of bearing / metal
I would stop driving it until you address the problem
 

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Yeah thanks, I jacked up the truck at work today, Im a diesel mechanic. Looking under by oil filter,etc. I finally googled it and yeah found it was on top at back of manifold. Changed the pressure switch which was ridiculously priced at like 67 dollars. Started it up and let idle and stayed at zero psi. Didnt want to take a chance reving it up. So I was thinking wire repair now probably. So long story short was going to go home at lunch, two minutes from work, and switch cars but it shot up to 40 psi and is working fine now. No oil leak thru the sensor. Maybe just me tweaking the wires to unplug and replug fixed it. Or actual pressure switch bad. Will know soon enough if it happens again. Your everywhere civteck. Was thinking about other comment. Not like temp switch where you have two sensors sometimes, one for computer and one for gauge. So dont know if scan tool would of helped me by reading oil pressure even if it could. Three wire oil sensor. I was hoping low oil pressure sensor reading wouldnt shut me down. Obviously I wasnt driving long miles but any driving could of possibly ate my bearings. Well working fine for now but freaked me out. Thanks guys.
Has it happened to you again?
If the oil pressure stays at zero mostly every time you fire it up and just tap the throttle it would rise up to normal?
Yuppers (bearings)
Keep me posted please
Good luck
 

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I had this happen with mine back in the day....AFTER changing the bearings, rod bolts, etc...and verifying sensor was good. What happened was the bypass in the oil pump hung open...literally bypassing all oil back to the pan (or pump intake...same thing). Anyhow, sadly, this was a common problem on many of the LS motors.... I put in a new Melling pump, problem solved.

DO NOT RUN IT!!! It probably has no pressure, and that story does not end well.
 

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I had this happen with mine back in the day....AFTER changing the bearings, rod bolts, etc...and verifying sensor was good. What happened was the bypass in the oil pump hung open...literally bypassing all oil back to the pan (or pump intake...same thing). Anyhow, sadly, this was a common problem on many of the LS motors.... I put in a new Melling pump, problem solved.

DO NOT RUN IT!!! It probably has no pressure, and that story does not end well.
Absolutely correct
But I already had the C-6 oil pan and melling pump and all upgraded within 8 months of this happening to mine.
 

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Discussion Starter · #12 ·
Has it happened to you again?
If the oil pressure stays at zero mostly every time you fire it up and just tap the throttle it would rise up to normal?
Yuppers (bearings)
Keep me posted please
Good luck
No everything is good so far. been acting fine. I have to look in my service manuals, dont know if bypass is on the pump or by the oil filter housing. Obviously if bypass was stuck open would cause low pressure. dont even know if it has a bypass. l wil look and get back on here soon.
 
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