Somewhat Fixed ! Low Oil Pressure at Low Idle !

[HiHoeSilver]

Where is this sensor located ?

At the back of the block on the top.

 

[iamdub]

Where is this sensor located ?

Top of the engine, at the back, behind the intake manifold. It's a pain (literally) to reach, but can be done without removing the IM. If you've never cleaned and sealed the knock sensors (assuming that's your rig in your avatar), you may wanna remove your manifold to do this and check and/or replace the oil pressure sensor and/or screen while you're at it.


Here's a pic of an LS engine in an F-body, but that's irrelevant. The intake manifold is removed and you can see the oil pressure sensor in the red square. The knock sensors are just in front of that in the valley cover under the two black circles with the wires going to them.

 

[JonnyTahoe]

Top of the engine, at the back, behind the intake manifold. It's a pain (literally) to reach, but can be done without removing the IM. If you've never cleaned and sealed the knock sensors (assuming that's your rig in your avatar), you may wanna remove your manifold to do this and check and/or replace the oil pressure sensor and/or screen while you're at it.


Here's a pic of an LS engine in an F-body, but that's irrelevant. The intake manifold is removed and you can see the oil pressure sensor in the red square. The knock sensors are just in front of that in the valley cover under the two black circles with the wires going to them.

Thanks Chris. Yes its the truck in the pic. I have noticed it before but never realized it contained a screen. Never had the Intake off but have removed the foam that comes from the factory in the front. I hear there is another in the rear. I will give it a shot with the Intake on and see how it goes. As long as its off I think I will replace it with a new one.

 

[iamdub]

Thanks Chris. Yes its the truck in the pic. I have noticed it before but never realized it contained a screen. Never had the Intake off but have removed the foam that comes from the factory in the front. I hear there is another in the rear. I will give it a shot with the Intake on and see how it goes. As long as its off I think I will replace it with a new one.

That foam helps to keep debris and water from getting under the IM and working it's way under the knock sensor seals and building up around them. It's a well-known issue and the fix is to remove the IM, pop off the wires and seals, vacuum out the water and/or debris, replace the knock sensors, and reassemble but with adding RTV sealant to those knock sensor harness seals. It's a good time to clean the oil and sludge out of the IM, too.

 

[HiHoeSilver]

Here's how you get at it.

 

[JonnyTahoe]

Here's how you get at it.

View attachment 181714


View attachment 181713

Thanks for the pics. I do have those exact tools and even blasted the back of the motor last summer to make changing that sensor a cleaner job.

 

[S_wall98]

I just did this and it fixed my low/no oil pressure at cold idle. LOL at a pro quoting 12 hours labor, it took me prob 8 but I was being slow and meticulous, no way a pro with a lift who works on cars day in and out takes 12 hours. Hardest part was maneuvering the front differential out of it's small space. You def need a small transmission jack to get it back in (I was able to remove with a regular jack and roping the diff off to the frame, ended up finding my old small Harbor Freight tranny jack later and using it on the re-install.). I took pictures and will make a guide available sometime soon, it's really pretty easy overall.

Looks like I'm bringing this one back from the grave.
Jagsta, did you ever get that guide made?