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

[Aburns70]

New to the site, first time posting but have been reading many of the other posts about the low oil pressure warning everyone has experienced.

Please bear with me as I am not a car person at all.

Situation: 2012 Chevy Tahoe 150k miles. Wife was driving it about 20 miles to our sons appointment, when ‘low oil pressure turn vehicle off’ warning came on. She drove it about 5-10 miles to the destination then turned vehicle off. I met her over there checked to see if there was any oil leaks, there was none, and to make sure there was oil, which there was. It had probably gone over 1k miles over recommended oil change. We had it towed to a shop near our house, we just moved and are new to the area and didn’t have a mechanic that we knew so tried this one spot with good reviews.

They said that it was probably the oil pressure sensor. I saw many people saying that was the culprit online so just assumed it would be a fairly straight forward fix. The quoted me 1k to diagnose, change sensor and give the vehicle an oil change, I felt that was fairly steep but like I said, I am no car person. So they went a head did the fixes and we picked up the vehicle on Friday the 15th. Drove the vehicle home, about 1 mile, no issues. Sunday I took the vehicle to the store about 10-15mile around trip and after the vehicle warmed up, I noticed I was getting less than 20psi on the gauge. So Monday morning I wanted to drive it to work which was about 20ish miles away. it was about 20 degrees out that morning, started up around 40psi, let engine warm for about 10 minutes, when I came back out it was down to 20, and progressively kept getting lower as I drove, until the ‘low oil pressure shut vehicle off’ warning came on again 5miles from work. Had it towed back to the shop, and it was there a couple days before getting a call today from them. They said that the oil was shiny, they tried going to 10w-30 oil to see if that helped, drove it about 7 miles and once the engine got up to temp, pressure dropped again. The mechanic told me that because the oil was shiny and it can’t keep pressure that the bearings were too warned down and that the only option was to rebuild the engine, and that it would cost in the ballpark around 5k to do that, but they wouldn’t rebuild the engine and we would have to find someone else to do that.

I have no idea what to do, would love to hear if anyone else has any tips or suggestions, or if I should look to get a second opinion.I can’t really afford an engine rebuild at this time, and not sure what to do.

Thank you in advance!

 

[strutaeng]

$1000 for an oil pressure sender!!! WTF, I'm in the wrong job!

Sounds like they should have checked pressure before condemning the oil pressure sender, which obviously wasn't the problem.

If you don't mind getting a little dirty, buying a harbor freight oil pressure mechanical gauge and climbing on the engine bay and hooking it up, that will be the best way to diagnose this.

 

[Aburns70]

$1000 for an oil pressure sender!!! WTF, I'm in the wrong job!

Sounds like they should have checked pressure before condemning the oil pressure sender, which obviously wasn't the problem.

If you don't mind getting a little dirty, buying a harbor freight oil pressure mechanical gauge and climbing on the engine bay and hooking it up, that will be the best way to diagnose this.

That’s what I was kind of wondering, the engine temp never overheated, and I never heard anything out of the ordinary from the engine noise, and performance hadn’t changed. So I wondered if I could manually check the engine pressure to see what it was actually reading, versus what the pressure sensor was reading.also wondering if they replaced the sensor but not the filter.

 

[strutaeng]

That’s what I was kind of wondering, the engine temp never overheated, and I never heard anything out of the ordinary from the engine noise, and performance hadn’t changed. So I wondered if I could manually check the engine pressure to see what it was actually reading, versus what the pressure sensor was reading.also wondering if they replaced the sensor but not the filter.

Yeah, although at this point it sounds like you do have legitimate oil pressure since you got a new sender.

I would still check with the mechanical guage.

I don't know much of the gmt900, but does this vehicle have that AFM/DoD stuff? I know those require higher oil pressure to operate that system.

I ran the original 4.3 on my 99 Silverado NBS with like 7-8 psi of oil pressure for like 1.5 years. I switched to the heaviest oil they sell, 50 weight and got an additional 2-3 psi at idle (down from like 5 psi.) Eventually I retired the truck and swapped the engine.

Look at some different threads about guys in similar situations, as far as your options and costs. There are a few recent threads...

 

[BG1988]

New to the site, first time posting but have been reading many of the other posts about the low oil pressure warning everyone has experienced.

Please bear with me as I am not a car person at all.

Situation: 2012 Chevy Tahoe 150k miles. Wife was driving it about 20 miles to our sons appointment, when ‘low oil pressure turn vehicle off’ warning came on. She drove it about 5-10 miles to the destination then turned vehicle off. I met her over there checked to see if there was any oil leaks, there was none, and to make sure there was oil, which there was. It had probably gone over 1k miles over recommended oil change. We had it towed to a shop near our house, we just moved and are new to the area and didn’t have a mechanic that we knew so tried this one spot with good reviews.

They said that it was probably the oil pressure sensor. I saw many people saying that was the culprit online so just assumed it would be a fairly straight forward fix. The quoted me 1k to diagnose, change sensor and give the vehicle an oil change, I felt that was fairly steep but like I said, I am no car person. So they went a head did the fixes and we picked up the vehicle on Friday the 15th. Drove the vehicle home, about 1 mile, no issues. Sunday I took the vehicle to the store about 10-15mile around trip and after the vehicle warmed up, I noticed I was getting less than 20psi on the gauge. So Monday morning I wanted to drive it to work which was about 20ish miles away. it was about 20 degrees out that morning, started up around 40psi, let engine warm for about 10 minutes, when I came back out it was down to 20, and progressively kept getting lower as I drove, until the ‘low oil pressure shut vehicle off’ warning came on again 5miles from work. Had it towed back to the shop, and it was there a couple days before getting a call today from them. They said that the oil was shiny, they tried going to 10w-30 oil to see if that helped, drove it about 7 miles and once the engine got up to temp, pressure dropped again. The mechanic told me that because the oil was shiny and it can’t keep pressure that the bearings were too warned down and that the only option was to rebuild the engine, and that it would cost in the ballpark around 5k to do that, but they wouldn’t rebuild the engine and we would have to find someone else to do that.

I have no idea what to do, would love to hear if anyone else has any tips or suggestions, or if I should look to get a second opinion.I can’t really afford an engine rebuild at this time, and not sure what to do.

Thank you in advance!

the oil pickup tube o-ring has failed and is bleeding oil pressure they would have stole your perfectly good engine..

 

[Aburns70]

the oil pickup tube o-ring has failed and is bleeding oil pressure they would have stole your perfectly good engine..

Is this a job I could do myself or something to leave to a mechanic? As far as the metal in the oil/shiny oil, is that something to be concerned about?

 

[BG1988]

Yeah if you have the tools you can
oil pan will need to come off though

also recommend replacing the 8 o rings on the vlom as well

 

[j91z28d1]

wait.. is it knocking? do you have the truck home so you can pull the dip stick and wipe the oil off with a white paper towel and see if there's any metal on it? you can test the o ring in the pan with the add extra oil trick or if you can find a steep driveway or something park on face downwards. the extra oil covers the o ring and if it's bad the pressure will come back up.


if it's not knocking or tapping when the low pressure light comes on. it's kinda hard to believe it's actually at zero. sadly not being a car guy at all, this is a bit of a deep end to jump into. 1000$ for the sensor is just criminal. they probably used some local parts place sensor, not a oem gm which is only like 50$. so you can't even rule out it being a bad sensor cause none oem can be unreliable even when new. they definitely could have not replaced or cleaned the screen under it also.

trying to think of the easy way to check the pressure with a mechanical gauge.. huh. it's kinda hard to get to where the sensor is and it doesn't have low pressure till it's hot. there's a adapter that replaces the oil filter, it's the easiest one to use, but being you gotta drive the truck to get it hot it's not good for it.

at this point you might just find another shop and ask specifically if they can put a mechanical gauge on it to confirm and actually walk you into the shop and show you. don't trust anyone.

 

[Aburns70]

wait.. is it knocking? do you have the truck home so you can pull the dip stick and wipe the oil off with a white paper towel and see if there's any metal on it? you can test the o ring in the pan with the add extra oil trick or if you can find a steep driveway or something park on face downwards. the extra oil covers the o ring and if it's bad the pressure will come back up.


if it's not knocking or tapping when the low pressure light comes on. it's kinda hard to believe it's actually at zero. sadly not being a car guy at all, this is a bit of a deep end to jump into. 1000$ for the sensor is just criminal. they probably used some local parts place sensor, not a oem gm which is only like 50$. so you can't even rule out it being a bad sensor cause none oem can be unreliable even when new. they definitely could have not replaced or cleaned the screen under it also.

trying to think of the easy way to check the pressure with a mechanical gauge.. huh. it's kinda hard to get to where the sensor is and it doesn't have low pressure till it's hot. there's a adapter that replaces the oil filter, it's the easiest one to use, but being you gotta drive the truck to get it hot it's not good for it.

at this point you might just find another shop and ask specifically if they can put a mechanical gauge on it to confirm and actually walk you into the shop and show you. don't trust anyone.

Damn I really appreciate all the responses so far. I feel stupid for not speaking up when they where giving me the quote, because I had read online that it wasn’t to bad to replace the sensor just that it was blind and you had to pretty much lay on top of the engine.

So let me kind of see if I understand this alittle better. Since there is no oil loss or leaks anywhere , most likely losing pressure through the faulty o-ring/rings. I haven’t heard or noticed any knocking or engine noise out of the ordinary, and didn’t notice any decrease in performance other than the pressure gauge. This wouldn’t be an issue with an oil pump? I haven’t

When I checked the oil level when it first was having issues before we got it towed I didn’t notice any actual metal shavings, obviously the dipstick looked shiny, but to my untrained eye I couldn’t tell you if was bad or not.

 

[j91z28d1]

don't take my word as official, just my experiences mixed with what I've read that makes sense to me. other guys here have way more experience with low oil pressure diagnostics over the web. in person with some tools is much easier haha.

so the o ring is on the suction side of the oil pump, if that o ring cracks it can suck air along with the oil, and you get foaming of the oil on the output side after the pump showing up at low pressure. it's a pretty common post around here at about the mileage you have, but others have changed it over low pressure and it not get much better. so it's a legitimate thing but not 100% you fix. that's why the test is to either add extra oil so it's above the o ring, or since the o ring is at the front of the engine, if you get on a steep hill nose down, oil will go forward and cover the ring to. I've not needed to do either test, but it's said you'll see the pressure come right up. you really should drain any extra oil you put in it back out thou after the test. high oil level can cause it's own set of problems.


I don't know how long these engines will run without oil pressure before they start to knock and tapping, but it should be tapping if it really has no oil pressure. heck, most ls engines tap a little with good oil pressure haha. so before you do anything drastic, I do think it's worth putting a real gauge on it. so the thing is, there's a little fine screen under the oil pressure sensor. because the sensor happens to be inline with the oil going to the active fuel management stuff and it needs to be extra clean for that. but if this screen gets clogged up, it's not blocking oil pressure to the main engine bearings, but it will block it from the pressure sensor and the AFM. what we don't know is if the shop replaced that screen or honestly if the sensor itself is even good.


it is what it is about the cost.. we all don't know what we know, and I've been taken before myself. drives me nuts but it happens. the gimmick is he probably billed you as if he had to remove the entire intake manifold to get to the sensor, which does make it eaiser and shop manual might even call for it. but it's not needed, I've replaced it both ways. it's not fun at all, but it can be done by laying across the engine with the right tools. but it's also very hard to replace that screen like that too since you can't really see what you're doing back there and you need a pick or a hook of some sort to pull it out.


any info on the maintenance history? the big question is usually was oil changes done every 4-5k miles, or by the much long change oil dash light. the long changes leads to gunk and sludge build up, which leads more clogging of that screen and the afm nightmare issues you'll read about if you search for afm.

so yeah, if you can test it either at the oil test port at the front of the engine with a mechanical gauge, or it hooked into the sensor port with the screen removed, you'll have a better idea what's really going on. how you get that done, I really don't know without knowing what you're comfortable with doing yourself.


I forgot to ask, once the oil pressure hits zero, how long do you have to have it off for the oil. pressure to come back up on restart. like 5 to 10mins or hours for the engine to cool completely?