🔧 Technical 04 Tahoe - Lower Oil Pressure

[PANDA]

2004 Tahoe 5.3
5w30 Amazon High Mileage Synthetic
GM Filter
Oil level is OK
20psi on cluster gauge warm idle.
Goes up with more RPM as normal
Runs perfect, no abnormal sounds.

I have been getting lower oil pressure recently and I think it has something todo with the oil and filter I am running. I have been running Amazon oil for probably 25K now with zero issues, even after two Black stone analysis, they still say I am getting better results verses my previous M1 oil and M1 filter. I usually change oil every 6-7K (DIC 30-40%) even though blackstone says I should go 10K. About 6K miles ago. 3K on the oil change and 50% on the DIC I started to notice lower than expected oil pressure. Just over 20psi on a warm idle. I thought to myself maybe its time for an early oil change.

After the oil and filter change the pressure goes back to normal. 30psi on warm idle.

Fast forward to a few days ago. I got another 3K and 50% on the oil life monitor and pressure is down again. I'm thinking maybe its time for another oil analysis or go back to the M1. Id really like to NOT change the oil every 3K. But I am not sure what's changed. I have been running this amazon shit for over 25K with no issues. Wondering if a change to the blend or filter? I wouldn't put it past a big company like Amazon to change something to make it work less effective and force the buyer to buy more of it. Not apposed to switch back to M1 either, I am not saving any money buying Amazon anymore.

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[EmersonHart13]

Bub would say 3k is the way.

 

[Yaj Yak]

when was the oil pressure sender replaced last.

 

[Bub]

when was the oil pressure sender replaced last.

This. Also fuck Bezos and his snake oil

 

[PANDA]

when was the oil pressure sender replaced last.

Never under my ownership. I'm just pointing my finger at the oil since it seems to fix itself after a oil change.

 

[Yaj Yak]

doesn't it have a newer engine in it

 

[Yaj Yak]

those sensors go bad frequently. those gauges are about as useful as a GM coolant temp gauge also.

 

[Yaj Yak]

also PANDA there's a specialty socket for them or something weird with it iirc. it's pretty straightforward though i think i did one in my burban and in my 2wd truck

 

[PANDA]

doesn't it have a newer engine in it

2004 with 160K now.

 

[Yaj Yak]

2004 with 160K now.

so, no ?

 

[DEEZUZ]

Rotella 15w40 and send it

 

[Yaj Yak]

also PANDA there's a specialty socket for them or something weird with it iirc. it's pretty straightforward though i think i did one in my burban and in my 2wd truck

https://www.amazon.com/dp/B0002SR2RY/?tag=tcg21-20

 

[PANDA]

https://www.amazon.com/dp/B0002SR2RY/?tag=tcg21-20

That some thing you can just remove like a 02 sensor? Need to drain oil first?

 

[CMNTMXR57]

Yep, the pressure sensor can be flaky. I'm actually surprised that it isn't either at 0 or at 80, and sometimes flipping between the two. There is also an O-ring on the oil pickup that can be an issue IIRC as well as a pressure relieve valve on the pump itself IIRC that can impact oil pressure on these.

You do not need to drain the oil. It is on the back of the engine, behind the intake. It is kinda a bitch to get to, and I would suggest getting the thing unplugged (usually the hardest part), and then putting the special socket on it first (you can get them at any auto parts store, I have 2 or 3 laying around), then putting an extension in it. You'll have a hard time getting it back there and on it with the extension/socket all in one piece.

Mine just went out on the 8.1 and it's even more of a bitch to get to believe it or not.

 

[PANDA]

Actually yes. The oil pressure sensor was replaced years ago with a GM unit. The location of it reminded me. I paid someone to replace it.

 

[CMNTMXR57]

Here, found a video. This guy ended up doing it the other way, putting the whole socket/extension/ratchet on at once. YMMV. But of course everything worked like a charm for him... Me, I'd break the fucking plastic retaining clip, break the plug, break the plastic on the sensor itself, have a bitch of a time getting it loose, etc... Because the ones I always get to work on were assembled by HeMan on a Wednesday after a power lunch at the gym and a 6-pack of Monster energy drinks.

 

[SaturdaysGS]

Yep, the pressure sensor can be flaky. I'm actually surprised that it isn't either at 0 or at 80, and sometimes flipping between the two. There is also an O-ring on the oil pickup that can be an issue IIRC as well as a pressure relieve valve on the pump itself IIRC that can impact oil pressure on these.

My ‘12 one day the oil pressure just dropped like a rock to 0, didn’t hear any clickety clack from the engine so I kept goin, ran fine no noise no issues except the chime dinging and DIC telling me to turn off the engine.. I ordered the part, it came in and a new screen and it started working again. Never did change it and then I got rid of it several Thousand miles later.. not sure what that was all about.

 

[CMNTMXR57]

It feared being worked on.

Mine happened a few weeks ago when I had the plow on. Driving down Stearns look down and the gauge is flipping from 0 to 80, to 0, then dead... Went and got a new sensor and figured 5 - 10 minutes I'll be good. Got in there, removed and relocated one of the wiring harnesses, disconnecting it to the alternator, TPS, and a few things, removing some brackets and the ground strap at the back of the engine only to find I could barely get my hand down there still and then there is the main wiring harness in front of it, so I couldn't even get to the plug. At which point it was 4pm, 30* out and I said "fuck it" this will be a spring day project when I can take a lot of shit apart.

It's gonna require me removing the back coil pack, disconnecting the fuel line and perhaps even more just to get my fingers on it.

 

[Bob Kazamakis]

Sensor is easy. It’s probably the oil pump pickup o ring.

 

[daturbosix]

Prob the sender. But before you deem the engine bad, put a mechanical gauge on it to verify.

Also, run thicker conventional oil. I run 10/40 in my caddy, and carl runs 15/40 in his silverado(225miles)

 

[PANDA]

If it could be a sender or o ring why did a oil change "fix" it for another 3000 miles?

 

[Blood on Blood]

Rotella 15w40 and send it

Send it with a 300 shot

 

[Yaj Yak]

you're believing the gauge.

quit it

 

[PANDA]

you're believing the gauge.

quit it

Does the gauge only read correctly with fresh oil?

 

[Yaj Yak]

the gauge never reads correctly ever.