Code P0521 help!!!

[mkoz]

Hi,
My '09 G8 GT has been to the dealer 5 times now for this 'low oil pressure' code. They've replaced the oil pressure sensor, the lifter filter, the oil pan relief valve, the oil pan itself (original leaked) and most recently the PCM (due to "internal failure"). I'm waiting for confirmation that their last diagnostic included checking the pressure with a manual guage. Can anyone think of anything else that could be causing this code? I know if the pressure really is low it could be the pump or pickup o-ring, but the engine sounds normal, so I suspect actual pressure is fine. Code seems to set most frequently when cruising at 55km/h with AFM engaged. Car is bone stock and otherwise behaving normally, just under 50K km on the clock.

Help!

[Crazy Paul]

P0521 is all about indicated oil pressure readings being way out of whack. Obviously you can't actually have 127psi or 1.16psi at the revs quoted below.

There's an electrical issue with voltages or the oil pressure sensor is fucked.


P0521
• The engine oil pressure is greater than 880 kPa (127.6 psi) and the engine speed is less than 640 RPM.
• The engine oil pressure is less than 8 kPa (1.16 psi) with the engine speed greater than 1520 RPM, engine oil temperature is between 80°C (176°F) and 110°C (230°F).
• The above condition is present is present for greater than 4 seconds.

See this thread: http://forum.grrrr8.net/showthread.php?t=29660

*** Replacing the Oil Pressure Sensor again with another new one is the next logical step.
Yes they do arrive faulty straight out of the box.

[mkoz]

See this thread: http://forum.grrrr8.net/showthread.php?t=29660

*** Replacing the Oil Pressure Sensor again with another new one is the next logical step.
Yes they do arrive faulty straight out of the box.


Thanks. I told them to order another sensor. It's going back in on Monday.

[GM Customer Service]

Hi,
My '09 G8 GT has been to the dealer 5 times now for this 'low oil pressure' code. They've replaced the oil pressure sensor, the lifter filter, the oil pan relief valve, the oil pan itself (original leaked) and most recently the PCM (due to "internal failure"). I'm waiting for confirmation that their last diagnostic included checking the pressure with a manual guage. Can anyone think of anything else that could be causing this code? I know if the pressure really is low it could be the pump or pickup o-ring, but the engine sounds normal, so I suspect actual pressure is fine. Code seems to set most frequently when cruising at 55km/h with AFM engaged. Car is bone stock and otherwise behaving normally, just under 50K km on the clock.

Help!


Mkoz,

I apologize for the concerns that you are having. What I would like to do for you is set up a Service Request number to document your concerns.. Please send me first and last name, address, phone number, VIN, current mileage and dealership.

Look forward to your reply!

Tina
GM Customer Service

[mkoz]

Mkoz,

I apologize for the concerns that you are having. What I would like to do for you is set up a Service Request number to document your concerns.. Please send me first and last name, address, phone number, VIN, current mileage and dealership.

Look forward to your reply!

Tina
GM Customer Service

Hi Tina,
Info sent via PM.

Thanks!

[mkoz]

See this thread: http://forum.grrrr8.net/showthread.php?t=29660

*** Replacing the Oil Pressure Sensor again with another new one is the next logical step.
Yes they do arrive faulty straight out of the box.


Oil pressure sensor got replaced for the second time today, unfortunately the code is back :(

[GRRRR8]

They need to hook up a mechanical oil pressure gauge and test it hot and cold. They really need to do it, not just say they did.

[Steve]

Perhaps your bypass valve in the pan in stuck open..
Of course I had the code too a few years ago after doing a stroker kit but my problem was I spun some cam bearings XD

[mkoz]

Perhaps your bypass valve in the pan in stuck open..
Of course I had the code too a few years ago after doing a stroker kit but my problem was I spun some cam bearings XD

The bypass valve has been replaced. That's not to say that it isn't sticking again. I'm trying to get my hands on software that will allow me to datalog extended GM PIDs so I can graph the oil pressure sensor data against PCM and battery voltage. I want to see if there is any correlation or erratic readings. The conditions for setting the code are almost always the same: cruise under light load 50-60km/h with AFM enabled. Today it happen while rolling in traffic on the way home. I have another dealer visit booked for next week and they want to engage the engineering group which leads me to believe they've done everything they said they did, including putting a manual guage on it.

[The Beej]

Mkoz,
My bet would be the oil pump. My dealer did everything including putting a manual pressure gauge to it, new pressure sensor etc. the light still came on. New pump problem fixed. Also even if you datalog, your still only going to see the psi the sensor sends to the computer not real time actual pressure, hence the suggestion for a direct pressure gauge.

Brandon

[mkoz]

Mkoz,
My bet would be the oil pump. My dealer did everything including putting a manual pressure gauge to it, new pressure sensor etc. the light still came on. New pump problem fixed. Also even if you datalog, your still only going to see the psi the sensor sends to the computer not real time actual pressure, hence the suggestion for a direct pressure gauge.

Brandon

I understand the datalog will only show sensor output. My thought was to see if there is anything else strange going on electrically at the time the sensor reads low. The car is back at the dealer today. Tech is talking to GM engineering. Let's see what they come up with...

[mkoz]

I understand the datalog will only show sensor output. My thought was to see if there is anything else strange going on electrically at the time the sensor reads low. The car is back at the dealer today. Tech is talking to GM engineering. Let's see what they come up with...

Good news. The car spent 3 nights at the dealer and they replaced the lifters and the lifter oil manifold. It's finally quiet on startup and it's been 3 weeks now with no code.

[mkoz]

Good news. The car spent 3 nights at the dealer and they replaced the lifters and the lifter oil manifold. It's finally quiet on startup and it's been 3 weeks now with no code.

My joy was premature. Code came back week 4. It's a lot less frequent than before, but still comes back within a couple of days of clearing. Wiring to oil pressure sensor was replaced, but still no love. The powertrain warranty is great, but if I could get frequent flyer miles with every dealer visit, I bet I could travel around the world by now. Car is back at the dealer, let's see what next week brings...

[GM Customer Service]

My joy was premature. Code came back week 4. It's a lot less frequent than before, but still comes back within a couple of days of clearing. Wiring to oil pressure sensor was replaced, but still no love. The powertrain warranty is great, but if I could get frequent flyer miles with every dealer visit, I bet I could travel around the world by now. Car is back at the dealer, let's see what next week brings...


We apologize for any frustrations you may be experiencing with this. Please let us know what the dealership was able to diagnose. We are here if you have any questions or concerns.

Brandon
GM Customer Service

[mkoz]

We apologize for any frustrations you may be experiencing with this. Please let us know what the dealership was able to diagnose. We are here if you have any questions or concerns.

Brandon
GM Customer Service

New oil pump is currently on order. Thanks.

[GM Customer Service]

New oil pump is currently on order. Thanks.

That's great that they were able to pinpoint this issue for you. Let us know how the repair goes.

Brandon
GM Customer Service

[-Ray-]

New oil pump is currently on order. Thanks.

Ask them to return the used pump!
If it's all scarred up, then so will be more parts scarred up.

[mkoz]

Bringing this thread back from the dead. I stored the car for the winter and put it back on the road a month ago. Code came back 2 weeks in. Car was the the dealer for the last 5 days, they couldn't get it to trip the code again. I got the code within 20 minutes of driving the car. I like the car and the dealer has been cooperative, but this is getting real frustrating.

G8 Ray: I forgot to ask and see the old oil pump

GM Customer Support: Please advise on next steps

[GM Customer Service]

Bringing this thread back from the dead. I stored the car for the winter and put it back on the road a month ago. Code came back 2 weeks in. Car was the the dealer for the last 5 days, they couldn't get it to trip the code again. I got the code within 20 minutes of driving the car. I like the car and the dealer has been cooperative, but this is getting real frustrating.

G8 Ray: I forgot to ask and see the old oil pump

GM Customer Support: Please advise on next steps

Hello mkoz,

Sorry you are having this issue and your dealer was not able to recreate for service. Could you private message me your name, address, VIN and current mileage and finally your involved dealer's information? I will make a record of your issue, and look further into your situation.

Reggie B.
GM Customer Care

[todds87ss]

They need to hook up a mechanical oil pressure gauge and test it hot and cold. They really need to do it, not just say they did.

this!!! you need to be able to see pressure.

[mkoz]

Oil pressure and wiring resistance checked out ok for the 2nd time, but issue is intermittent. GM TAC made the call, complete new engine is on order. Apparently TAC has seen this with one other L76. Now we wait...

[-Ray-]

Oil pressure and wiring resistance checked out ok for the 2nd time, but issue is intermittent. GM TAC made the call, complete new engine is on order. Apparently TAC has seen this with one other L76. Now we wait...

Nice!

[todds87ss]

good for you! Hope the problem is gone for good. (I wonder if the used longblock would then be for sale ;))

[hflores3]

good for you! Hope the problem is gone for good. (I wonder if the used longblock would then be for sale ;))

LOL!!!! You scavenger! :-)

[hflores3]

Hey Mkoz, you wouldn't have done a DOD delete - did you? I had big P051 DTC codes -- after the DOD removal. Turns out it was the lower valley plate! Replaced it with the Non-DOD Valley Plate - Bingo! Problem solved.

[mkoz]

good for you! Hope the problem is gone for good. (I wonder if the used longblock would then be for sale ;))

I was wondering what they do with those, I doubt they go back to engineering for analysis if it's an issue that affects a small number of units. I'm gonna ask, but I imagine they have to scrap them. It would make for a nice project power plant with a DoD delete.

[mkoz]

Hey Mkoz, you wouldn't have done a DOD delete - did you? I had big P051 DTC codes -- after the DOD removal. Turns out it was the lower valley plate! Replaced it with the Non-DOD Valley Plate - Bingo! Problem solved.

No, car is bones stock and all work is being done under powertrain warranty. The valley plate was one of the last items replaced last season and the code went away for a few weeks, but eventually came back.

[GM Customer Service]

Oil pressure and wiring resistance checked out ok for the 2nd time, but issue is intermittent. GM TAC made the call, complete new engine is on order. Apparently TAC has seen this with one other L76. Now we wait...

mkoz,

Great news! Happy to hear that your issue is on the way to get resolved. Do keep us informed on the progress.

Reggie B.
GM Customer Care

[mkoz]

Got the car back on Friday. New engine is in and so far so good.