new 2009 Tahoe LTZ owner

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stretchb1953

stretchb1953

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Got a new problem now. New code P0521 oil pressure. went and got an oil pressure sensor and screen. picked up the tahoe from stepdaughter's work and drove it home. pressure indicate less than 20 psi at idle but climbs to about 30 at 60MPH.. got home and tried to access the POS sensor and found it buried under a plastic panel. how the heck do you remove that panel, shgrt of a dremel tool? and what is it there for? am starting to wonder what other codes are gonna start popping up one after the other.
ok all. replaced the oil pressure sensor and screen. did my leak check and function check. oil pressure is still about 20 PSI at idle. man it was a pain to change but got it done. next question is, what's next? and hopefully it ain't an oil pump.
 
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stretchb1953

stretchb1953

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20 psi at warm idle is normal/okay.
whew thanks for that info. i thought it should be higher, like around 30 or 40 PSI. at highway speed it may get up to 35 PSI or so. i'm so used to seeing pressures around 40 PSI at all engine speeds that this kinda scared me. my trailblazer and tundra both run at about 40 PSI.
 
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stretchb1953

stretchb1953

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When I replaced my engine almost 3 years ago, I removed that plastic shield and have had no issues. I recently also had the P0521 code and was able to easily remove the oil pressure sensor without that plastic shield in the way. The only thing you should keep on back there is the metal bracket that looks like a spoon, I believe it is a protector for the fuel rail in case of a bad front end collision.
think the shield can be removed without removing the intake?
 
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stretchb1953

stretchb1953

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whew thanks for that info. i thought it should be higher, like around 30 or 40 PSI. at highway speed it may get up to 35 PSI or so. i'm so used to seeing pressures around 40 PSI at all engine speeds that this kinda scared me. my trailblazer and tundra both run at about 40 PSI.
just checked the Tahoe after a day of driving. P0521 code is back, so apparently 20PSI to 25PSI is not enough pressure to keep light off. also it only climbs to about 30PSI at 60 MPH. i'm thinking about trying some 10W-30 oil to see if pressure increases. if it doesn't help keep that CEL off, then guess i'm going to have to bite the bullet for a new oil pump and pickup screen. would do it myself, but i don't have a decent place to work on it. i do all my maintenance in my driveway.
 

solli5pack

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just checked the Tahoe after a day of driving. P0521 code is back, so apparently 20PSI to 25PSI is not enough pressure to keep light off. also it only climbs to about 30PSI at 60 MPH. i'm thinking about trying some 10W-30 oil to see if pressure increases. if it doesn't help keep that CEL off, then guess i'm going to have to bite the bullet for a new oil pump and pickup screen. would do it myself, but i don't have a decent place to work on it. i do all my maintenance in my driveway.
If anything the issue is the o-ring on the pick-up tube deteriorated and the tube is sucking in air causing low oil pressure. The oil pumps on these things don't fail often. O-ring replacement can be done in a driveway.
 
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stretchb1953

stretchb1953

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If anything the issue is the o-ring on the pick-up tube deteriorated and the tube is sucking in air causing low oil pressure. The oil pumps on these things don't fail often. O-ring replacement can be done in a driveway.
thank you for the reply. still have to do a lot of part removal just to get to the pickup tube. oil pan removal, not to mention drilling rivets out that hold factory gasket on oil pan (if it is still factory gasket). also according to what i have seen and read, removing a cross member frame, maybe a skid plate if one installed. just a lot more work than my 70 year old butt wants to tackle.
 
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donjetman

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just checked the Tahoe after a day of driving. P0521 code is back, so apparently 20PSI to 25PSI is not enough pressure to keep light off. also it only climbs to about 30PSI at 60 MPH. i'm thinking about trying some 10W-30 oil to see if pressure increases. if it doesn't help keep that CEL off, then guess i'm going to have to bite the bullet for a new oil pump and pickup screen. would do it myself, but i don't have a decent place to work on it. i do all my maintenance in my driveway.
Oil pressure doesn't seem "too" low to me.

To achieve higher oil pressure at operating temperature (100*C), us an oil with a larger second #. The first # is an indication of its cold (40*C) viscosity.
Mobil 1 and others make 5w-40, and even a 5w-50.

Here's a viscosity/temperature chart.
viscosity charts.jpg
 

solli5pack

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thank you for the reply. still have to do a lot of part removal just to get to the pickup tube. oil pan removal, not to mention drilling rivets out that hold factory gasket on oil pan (if it is still factory gasket). also according to what i have seen and read, removing a cross member frame, maybe a skid plate if one installed. just a lot more work than my 70 year old butt wants to tackle.
It's definitely not easy. Especially if it's 4x4.
 

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