10 psi when warm

[JohnnyA]

If the bearings were blown but all else was OK, I would expect a +/- linear increase up to the oil pump bypass valve opening.
Snowdeifter I'm not registering. The difference between the two gauges changes depending on oil temp and rpm. The first gauge is a machanical post oil pump port on the block driver side behind the power steering pump. I am using torque pro for the screen shots that I uploaded.

 

[JohnnyA]

Thank you RAMurphy I will have a look see.

 

[RAMurphy]

Thanks everyone! I removed the machanical gauge post filter and replumb the oil cooler lines. Cold start mid 35 at machanical gauge and 20 at sending unit. However, when warm the machanical gauge post oil pump is 20 psi and sending unit is 6-8. Presure looks barely adequate 1psi per 100 rpm up to 2700 rpm then it is below 1-100. Lq4 and m32 are original and untouched. 1700 rpm = 35 at machanical gauge 20 psi at sending unit. Looked through transmission for a look see and no oil on fly wheel. I felt some residue underneath and unknown if it's from a engine wash job that I did. Also knock sensor bank 2 came on unknown if it's from me washing the engine down essentially at the sending unit. I tell you now luck. Is it possible to refresh trany with corvette servo or what is best for towing. My trailer is 6000lbs and hauls very nice. I am in no hurry when towing. 60-65 mph thank you everyone .

@JohnnyA As most have already stated, that oil pressure is low - not good. Your situation reminds me of mine. Around the 230k mark I noticed my oil pressure was lower than it had been. Following the posts in this forum I did all the troubleshooting and r/r suggested. Nothing brought the pressure back. After another 5k miles I started getting a random knock sensor code that I couldn't find a reason why. After another 5k or so I developed a substantial knock. Removed the engine and took it apart and found I had two camshaft bearings that failed. I ended up dropping an upgraded 5.3l crate engine in instead of getting this one rebuilt. Love this new engine but wish I dropped in a 6.0.

 

[THarber]

If you just had an oil pump put in then I would d1st look towards the oil pump o-ring and pick up tube seal. It can fail and cause exactly what you're going thru.

As far as your transmission. the 4l80 has a different set of gear ratios, you might not be happy with what you end up with. I'd build what you have. You can make a 4l65e bullet proof just as easy. I could spin all 4 tires of my H2 with no issues with my built 4l65e behind a 500hp plus LS but it was to handle it.

 

[SnowDrifter]

If the bearings were blown but all else was OK, I would expect a +/- linear increase up to the oil pump bypass valve opening.
Snowdeifter I'm not registering. The difference between the two gauges changes depending on oil temp and rpm. The first gauge is a machanical post oil pump port on the block driver side behind the power steering pump. I am using torque pro for the screen shots that I uploaded.

What's your config for the pid?

Iirc there's a port on the front left side of the block that's a leftover from machining. I'm quite curious what the oil pressure is there.

 

[JohnnyA]

This is the pid I used. Pid is off another forum. Typically my oil pressure is about half at the sending unit in comparison to the machanical gauge just after the oil pump outlet. I'm going to tear into the engine next month. Everything goes on hold in September... if it is the cams bearing I'm probably going to just replace and put back together. Engine is still plenty strong. I don't push it that much.

 

[RAMurphy]

@rockola1971 Great information and I filed it away if I end up blowing up my heavy upgraded 4L60. I've been at the cusp of upgrading to the 4L80.

 

[SnowDrifter]

Yeah the PID config looks correct. Was hunting if there was a typo in the equation.


If you do the cam bearings, HAVE THEM LINE BORED after install. These engines have a small, though non-negligible chance of spinning the cam bearings if this step is skipped. The block isn't quite as straight and warp free as we like to think it is. Line boring corrects that.

Though, I maintain: it sounds like there's an obstruction in the oil passages if your pressure is cut in half between pump and sending unit.

 

[JohnnyA]

Snowdrifter should I blow some air or pressurize some oil and put through oil passage?

 

[SnowDrifter]

Good idea! See if you can reverse-flow it. Or maybe even shove a boroscopic camera up there if you have one