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Jerry Newton
Jerry Newton, Chevy Technician
Category: Chevy
Satisfied Customers: 4458
Experience:  ASE Master Technician, L1, Master GM Technician. Over 20 years of bumper to bumper GM experience.
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Chevrolet Cruz: We are having the same issue...we went thru

Customer Question

We are having the same issue...we went thru 3 used turbos and the customer finally got a reman from the dealership....the original turbo failed from the feed line plugged up...both feed and return are new and the drain is clear we put a camera in the drain and it is clean...is it possible on this engine having some kind of pressure valve if its getting to much oil pressure to be pushing oil out of the turbos?
Submitted: 1 year ago.
Category: Chevy
Expert:  Jerry Newton replied 1 year ago.
I would start with an actual oil pressure test, using a handheld gauge. I'll attach the procedure, the oil pressure is normally pretty high on these, but testing is the only way to know.
Customer: replied 1 year ago.
That is an electrical diagram, not what we need. Is it really possible that all 4 of these turbos could have been bad? The only way I can test the oil pressure to the turbo is if i fabricate a test port on the oil feed to the turbo.
Expert:  Jerry Newton replied 1 year ago.
Sorry, I gave you the wrong attachment. The idea here is not to test oil pressure to the turbo, but to test the engine oil pressure, by removing the oil pressure sending unit and attaching a handheld gauge.
Customer: replied 1 year ago.
The idle psi is 55-60 and 3500 rpm is 70-75 psi. I cannot believe that I have installed 4 turbos, and they are all doing the same thing.
Expert:  Jerry Newton replied 1 year ago.
There is no other explanation for it, unless you have some sort of intermittent high oil pressure issue (not very likely, but nothing it out of the question). So, is the latest turbo also leaking?
Customer: replied 1 year ago.
yes and this one came from the dealer...i am a small shop just so u know and sometimes i just need another mechanics thought...and i do believe since this did fail this will have to go to the dealership...
Expert:  Jerry Newton replied 1 year ago.
I also own/operate a small shop, so I feel your pain. I can't see that there's anything wrong with the rest of the car, though, it doesn't make any sense. It does not need to go to the dealership for warranty repair, call your local dealer and talk to the warranty administrator. GM will reimburse your shop for the parts and labor to make this warranty repair, but it's up to your local dealer to facilitate it.
Customer: replied 1 year ago.
Hey Jerry we installed another GM turbo today and its sill pushing oil.....it idled for about ten minutes and then the oil started dripping out of the pressure side....is it possible it having more oil press at the turbo? This thing have some kind of oil pressure relief? thanks Tommy
Expert:  Jerry Newton replied 1 year ago.
Hi TommyHoly cow, again? Your oil pressure at idle should be 22psi, is that still an accurate number? I'd be testing it again.
Customer: replied 1 year ago.
The PSI is 60 at idle. We did research and found out that there is a valve in the oil housing assembly. We believe that the piece that was lodged in the oil feed tube for the turbo came out of the oil filter housing. Is the pressure at the oil pressure sensor the same as the oil feed to the turbo?
Expert:  Jerry Newton replied 1 year ago.
The oil pressure should be consistent across the whole engine, so yes, it seems that the oil pressure is high. The oil pump has the ability to modulate pressure, but my guess here would be that you'll find the oil pump stuck to the max side. It looks like you're putting an oil pump in this. If it's 60psi at idle, and it's not modulating, it's probably 3 times that when you rev it up. I don't know why I didn't notice this high oil pressure issue the first time you mentioned it, or I didn't notice that the spec was 22psi at idle. That's why I like to provide the written procedure to my customers, in case I miss a detail like that. According to the oil pressure specification... your oil pressure is too high here at idle.
Customer: replied 1 year ago.
The oil pressure will drop when its hot but not to 22psi...the oil gauge is still on the car..at 3500rpm it varies between 70-75psi hot...so you are telling me that the oil pressure relief valve is in the oil pump? i was doing some research today and there is some kind of valve made in the feed port for the turbo...but what i dont understand is if the spec at 3500 is 55-94 why is this turbo leaking at 60psi? This car needs a bomb....I tell you when u fire it up this crapper smokes!!! thanks Jerry for your continued support on this!!
Customer: replied 1 year ago.
The feed port that is in the oil filter housing...
Expert:  Jerry Newton replied 1 year ago.
The oil pump is like a variable displacement.... that's not the correct term, I can't remember what it's called, but it's like a transmission pump where it has the ability to increase or decrease pressure and flow by making the pump area larger and smaller. I was doing some reading about it this morning on your behalf. What it sounds like is that this pump has swung over to maximum pressure and is stuck there. I'd want to access the pump and just look at it while carefully disassembling it, to see if that is what has happened inside the pump. I agree that it's getting ridiculous with these turbochargers, they simply can't all be bad. I missed the lower spec on the oil pressure on the first read, but upon reviewing what we have here, it seems like that pressure is high at idle when compared to the spec/procedure.
Customer: replied 1 year ago.
If you read back there was a blockage in the turbo feed line so with having a blockage i think this is what caused it?
Expert:  Jerry Newton replied 1 year ago.
I did see that, but I can't make any connection between that (which is fairly common) and the oil pump issue. We don't know what kind of debris is in the pan... anything that can get past the pickup screen can potentially block the oil pump wide open, at least theoretically.
Customer: replied 1 year ago.
Dropped oil pan and found pieces of what looked like brass (see picture) Removed oil pressure relief valve. Where exactly is the oil pump in this motor? How do we get to it? Is the oil pressure relief valve the reason it is stuck on the high oil pressure? Could it be from all the pieces of metal we found in the oil pan?
Expert:  Jerry Newton replied 1 year ago.
The oil pump is under the front cover of the engine, it's driven directly by the crankshaft. When you get to it, you'll see what I'm talking about, how it closely resembles a transmission pump. It has vanes in it, and variable displacement using a spring loaded lever. I believe you'll find that it's stuck to one side. I don't know what those pieces are, however, I don't recognize them. Chain tensioner parts, perhaps? Removing the front cover will probably reveal the source of all your troubles.