Tahoe idle oil pressure

[Sam Harris]

This is why I bought a subscription to alldatadiy so I have access to the factory service manual.

Totally worth it!

 

[MassHoe04]

This is why I bought a subscription to alldatadiy so I have access to the factory service manual.

Not as fancy as the Alldata online, but I did go out and get the PDF FSM from an Ebay seller. I have mine on my Google Drive. Maybe not as easy to navigate as Alldata, but I can have access to the manual for my model year if I need it. Sometimes it is nice to have diagrams in front of you when watching some of the Youtube videos as a reference. Exploded views, parts lists and wiring diagrams are really handy. They also have Tech 2 specific diagnostic steps outlined, which can also be helpful.

I agree... You need all the help you can get! Anything you can get your hands on, preferably before you actually need it...

 

[Spaul]

Not as fancy as the Alldata online, but I did go out and get the PDF FSM from an Ebay seller. I have mine on my Google Drive. Maybe not as easy to navigate as Alldata, but I can have access to the manual for my model year if I need it. Sometimes it is nice to have diagrams in front of you when watching some of the Youtube videos as a reference. Exploded views, parts lists and wiring diagrams are really handy. They also have Tech 2 specific diagnostic steps outlined, which can also be helpful.

I agree... You need all the help you can get! Anything you can get your hands on, preferably before you actually need it...

Does the FSM have sensor data ranges to diagnose?

 

[MassHoe04]

Reference voltage for the gauge is between 0 and 4.6 volts.
The PSI on the cluster would be linear in readings that correspond to the voltage from the pressure sensor.

Signal at half the voltage would read in the middle of the range. With the minimum being 0 and the maximum being 99, a voltage signal from the sensor of approximately 2.3 would display as approximately 50 PSI on the cluster gauge.
Voltage of 4.6 would be maxed out on the gauge. A signal of 0 V would, of course would be 0 PSI on the gauge (either actual 0 PSI or a problem in the circuit).


Not sure if this helps, but this is what the FSM says...



Displayed Oil Pressure


The scan tool displays 0-682 kPa (0-99 psi). The displayed oil pressure gage value in the IPC.


Engine Oil Pressure Sensor


The scan tool displays 0 to 5 volts. The PCM monitors the engine oil pressure sensor signal circuit where
a low voltage indicates low pressure.

Oil Pressure - Minimum - Hot

6 psig at 1,000 engine RPM

18 psig at 2,000 engine RPM

24 psig at 4,000 engine RPM

EOP Sensor Terminal Identification



Pin Wire Color Circuit No. Function

1 BLK 2755 Low Reference

2 GRY 2705 5-Volt Reference

3 TAN/WHT 332 Oil Pressure Sensor Signal

 

[JPVortex]

Getting the front diff back in was a PIA, decided to put in the diff before the right axle shaft housing and it was a very hard fit, got it in tho
Have a feeling its gonna leak in between the diff and the axle shaft housing as I just put some rtv around it and it was not very good bead of rtv. Probably got some inside the housing too but I'm not too worried about it with all the oil that'll be splashing around it

 

[JPVortex]

Well everything's back together but 4wd is having an issue. Most of the time when I go to engage it, it makes this clank noise as shown in the video. And its sometmes not wanting to shift to and out of 4wd. I put those 2 washers in, tried flattening them the best I could but they aren't perfect. I'm wondering if those are hitting the axle shaft or something? Not sure tbh.

Video: https://drive.google.com/file/d/1dLBx4TDnrT-Wa07kvhfp5zTKflg1j9uC/view?usp=drivesdk

 

[JPVortex]

Actually I think I'm stupid, I think a clunk to and from 4 low is normal

 

[West 1]

I have fixed many with low oil pressure, did one with 270,000 miles on it. Installed the Melling High Volume Oil Pump along with the new Pick up tube Oring and it has 50 PSI at hot idle now. Be very careful choosing your new O ring for the pick up tube, there are 2 or 3 different designs, melling supplies pictures and a couple orings to get this correct.
I just fixed an 08 that had zero oil pressure at hot idle and the lifters started clacking a sure sign of low oil pressure. After pan removal the pick up tube fell out when I removed the bolt, sure sign it had a bad Oring, the O ring was flat and brittle not doing its job. New Oring and the original pump left in the engne at 170,000 miles and it now has 30 PSI hot idle oil pressure and 60 PSI at 2,000 RPM hot. GM says you are fine with only 10 PSI at idle but no body likes low oil pressure. ( the 07 and newer AFM engines need a minimum of 26 PSI at idle or the AFM system which allows running on 4 or 8 cylinders will not work.) In your case I would change the oil and filter, use a quality filter like Wix, use a quality oil, I might use a 5-40 instead of a 5-30 and see what you have. If your 05 is 4wd, taking the oil pan off to remove the pick up tube is complicated by the front differential but still not really too hard I would plan to have an entire day available if you tackle this job. Not hard just time consuming and messy. Less mess if you can let the engine sit for a day before taking off the pan allowing most oil to drip down into the pan before you remove it. They will drain down to the pan for hours after running.

Almost every one of the 5.3L engines I worked on are leaking at the Oil Cooler adapter plate right above the oil filter, I have used both the Mahle or Fel Pro gasket available to reseal this block off plate. It makes oil leak down right at the oil filter and to the back of the oil pan. $10 gasket, 2 10mm bolts and you can eliminate this leak while doing a normal oil change. With the filter out it is easy to access the bolts for repair. Again, there are two types of gaskets for this job, the gasket with two small holes only works if you actually have an engine oil cooler, the gasket with one large rectangle hole in it fits all other trucks. Most do not have the external oil cooler. It is a heavy duty option.

 

[West 1]

Yep, they all clunk when shifting from 2wd to 4 low which has to be done in neutral, 2wd to 4wd high is silent normally.

 

[Fless]

Yep, they all clunk when shifting from 2wd to 4 low which has to be done in neutral, 2wd to 4wd high is silent normally.

x2 Tap the dash button once and give it a few seconds to change modes.