2012 Chevy Tahoe low oil pressure/ shop says I need new engine!

[j91z28d1]

man these threads are just painful to read.

I honestly don't know what I'd do in your position without repairing cars most of my life. it's just painful to watch.


when I say it's amazing what they charged you don't take it as a knock on you. I'm sure I've been taken a lot of times in fields I don't know much about. I'm just blown away they can charge that for a sensor that I just walked into gm parts dealer a few months ago and paid like 60$ for with tax. ugh.


I like the add oil idea and to check the o ring, and then personally I'd change it and put a thicker 15w40 or something in and drive it till it's atleast got a knock or some sign something actually wrong before replacing an engine. in the mean time, I think I'd consider after watching some YouTubes, buy a oem gm sensor and screen from rock auto and try changing it yourself. it's not fun but the sensor and price of a tool kit you'll spend less than they billed you for just a sensor of a unknown brand and quality or if they actually did change the screen. we don't know that they actually removed the intake, because you really don't need to but it does make the screen easier to get out. I don't know a flat rate tech alive that will remove a whole intake when there's a simple short cut. it's the reason they spend 1000s of dollars on the tool truck for special tools.

 

[Dustin Jackson]

Presuming there are any.....
if I was a honest mechanic as soon as I found metal indicating internal engine damage I am going to stop work period, right there and reach out to the customer and have them come down and make a educated decision, show them the metal and maybe I get the work and maybe I don't but no sense in stringing someone along. either way i got paid so far.
these guys overcharged for minimum effort.

@Doubeleive Are you saying it’s possible that there really isn't metal flakes in the motor? This is turning into a bit of a roller coaster here

When I was asking local mechanics for advice with my AFM delete I got about a dozen and a half different opinions so I wouldn’t be surprised if OP was led astray.

 

[GREGB1954]

Let me share my experience with the similar symptoms: We have a 2007 Tahoe, 145000 miles. Suddenly the low oil pressure/turn engine off light came on. Oil level was fine. Light went off. Days later same thing. I paid a mechanic $500 to replace the sensor with an AC Delco premium INCLUDING the little screen that goes in first. I have worked on cars for over 50 years and this was just too difficult to reach. Then the oil pressure was reading low, like 20 psi high and 10 psi at idle. The mechanic told me that I likely needed to replace the cam bearings. Keep this in mind: If the oil pressure was truly low then the hydraulic valves would be clattering. Then the warning came on again with the new sensor, but went off again.

Someone here suggested running Motor Medic flush following the instructions. I think it is like put a quart in, start and idle for 5 min. Drain and replace oil. I was told by my mechanic to try a High Mileage oil so I used Valvoline's brand. Voila!! Oil pressure now just over 40psi and idles at 20psi. The light has not come back on.

My conclusion is the oil pressure sensor screen got plugged up with gunk. New one went in and had gunk intermittently blocking the new sensor. The oil flush got rid of the gunk and combined with the High Mileage oil my pressure at the sensor and the entire engine was restored.

 

[donjetman]

If it were mine I would:

send an oil sample to a lab for analysis, like Blackstone-Labs, JG Lubricant Services, Oil Analyzers Inc, Wix, Polaris Laboratories. I always have about 5 sample kits on hand. Results will tell the tale (metal in oil or not).

Overfill the engine by 2 qts of oil. Warm it up to normal operating temperature until the oil pressure drops. Jack the rear of the vehicle up and see if the oil pressure returns to normal. If so its the oil pickup o-ring needs changing.

Change the oil pressure sender screen and sender.

If its not making any unusual noises? like Valve train rattling, rods knocking, it isn't hurt bad.

Last resort: chemical engine flush

 

[Doubeleive]

@Doubeleive Are you saying it’s possible that there really isn't metal flakes in the motor? This is turning into a bit of a roller coaster here

When I was asking local mechanics for advice with my AFM delete I got about a dozen and a half different opinions so I wouldn’t be surprised if OP was led astray.

I was told by a mechanic once that a transmission had metal flakes in it while getting a flush, someone that I had dealt with many times, I drove that thing almost 100k and sold it and never had a single problem, so unless the mechanic showed him the flakes on a cloth or something I wouldn't trust it under many circumstances the picture of the dipstick shows pretty clear clean oil. Doesn't mean the mechanic is making it up, but I would add the extra oil as a test and see what happens and otherwise just drive it and keep checking the dipstick for flakes. Not everyone is honest

 

[2008yukonxlslt]

If it were mine I would:

send an oil sample to a lab for analysis, like Blackstone-Labs, JG Lubricant Services, Oil Analyzers Inc, Wix, Polaris Laboratories. I always have about 5 sample kits on hand. Results will tell the tale (metal in oil or not).

Overfill the engine by 2 qts of oil. Warm it up to normal operating temperature until the oil pressure drops. Jack the rear of the vehicle up and see if the oil pressure returns to normal. If so its the oil pickup o-ring needs changing.

Change the oil pressure sender screen and sender.

If its not making any unusual noises? like Valve train rattling, rods knocking, it isn't hurt bad.

Last resort: chemical engine flush

I like the oil analysis idea, that will tell if and what parts in the engine maybe falling apart. Isn’t the oil plug magnetic? Cant you just pull the oil plug out and inspect for metal, not as good as the analysis but cheap and easy.

 

[donjetman]

I like the oil analysis idea, that will tell if and what parts in the engine maybe falling apart. Isn’t the oil plug magnetic? Cant you just pull the oil plug out and inspect for metal, not as good as the analysis but cheap and easy.

ferris metals (iron, steel, etc) yes.
Non-ferrous (lead, copper, aluminum, etc) no. Bearings are non ferrous.

 

[petethepug]

When the shop had the intake off you should have been provided info on the valley cover underneath. My $8h oil pressure sensor in my 09 included a diagnosis and repair of leaky valley cover gaskets, the clean up, parts, as well as the gaskets for the intake.

The shop got me a good bang for the buck on labor as well as offering the opportunity to decline it. You can see the oil sensor sticking up at the back of the motor.





This is an 09 6.2L w/o AFM so the valley cover plate looks a little different.

 

[Fubar0715]

I cannot get over the $185 part - I did mine for the low pressure issue and the warning messages. The sensor and screen helped a little (enough the messages didnt return) however, I bit the bullet and pulled the oil pan. I think I am all in at this point with new O-ring, pan gasket, sensor and screen, oil cooler filter, and 2 oil changes with filter - must be less than what that "professional" shop charged. That hurt just looking at the bill but, in your defense, you were in a bind and trusted they knew what they were talking about. If it were me, do the O-ring on the pick up tube and roll with it - FWIW, I run the recommended oil with a PF63 filter and mine runs about 45 cold and 25 hot with the gauge climbing when the loud pedal is pressed.

 

[Aburns70]

Let me share my experience with the similar symptoms: We have a 2007 Tahoe, 145000 miles. Suddenly the low oil pressure/turn engine off light came on. Oil level was fine. Light went off. Days later same thing. I paid a mechanic $500 to replace the sensor with an AC Delco premium INCLUDING the little screen that goes in first. I have worked on cars for over 50 years and this was just too difficult to reach. Then the oil pressure was reading low, like 20 psi high and 10 psi at idle. The mechanic told me that I likely needed to replace the cam bearings. Keep this in mind: If the oil pressure was truly low then the hydraulic valves would be clattering. Then the warning came on again with the new sensor, but went off again.

Someone here suggested running Motor Medic flush following the instructions. I think it is like put a quart in, start and idle for 5 min. Drain and replace oil. I was told by my mechanic to try a High Mileage oil so I used Valvoline's brand. Voila!! Oil pressure now just over 40psi and idles at 20psi. The light has not come back on.

My conclusion is the oil pressure sensor screen got plugged up with gunk. New one went in and had gunk intermittently blocking the new sensor. The oil flush got rid of the gunk and combined with the High Mileage oil my pressure at the sensor and the entire engine was restored.

Hey Greg, I actually just did this today even though the oil had just been changed. I added it, ran for exactly 5 minutes then changed the oil and filter, this was my first time changing my own oil, still feeling anxious about it as I am very much a noob when it comes to cars. It was idling at about 21-22psi for about 10 minutes before I had to go inside. I saw someone on YouTube to do this as well. I should note that the person in the YouTube video did this after they already replaced their oil pickup tube oring, and this finally helped get his cars psi back to normal.