CEL Oil Pressure Sensor

**Eddie Jackson** · 07-12-2012

As I was driving to work this morning, I noticed my Check Engine Light came on. A few moments later, the Low Oil Pressure warning came on the DIC with the Oil Light on the cluster, but turned right back off. A few minutes later, the Low Oil light came on again, but went off as I let off the gas. After checking the code, I found: P0521 (Oil Pressure Sensor) and P0522 (Low Oil Pressure, I believe). The low pressure light has never came back on, but CEL stays on, and came back on after I cleared it (with code P0521). I plan on picking up an oil pressure sensor when I get off to replace after I check the pressure with a manual gauge. Anyone know what the pressure range should be when I check at idle??? Any reason it is only low when I was driving, but went off when I let off the gas??? I was wondering maybe oil pump (knock on wood it's not). Could it let the pressure be low at times then normal at others??? Hoping it's just a sensor, but I'm wondering if it IS a faulty sensor, could it have been low all along, but not told me??? Anyone else had this happen or have anything I might try to troubleshoot if the new sensor doesn't solve it??? Thanks for the help!!!

**BillBoost37** · 07-12-2012

Warm idle... 30-50, cold 40-60

**Eddie Jackson** · 07-12-2012

Originally Posted by BillBoost37

Warm idle... 30-50, cold 40-60

Awesome...thanks!!! Will update as soon as I get it checked!!!

**Eddie Jackson** · 07-16-2012

Okay...got the manual oil pressure gauge installed today. Pressures were:

46 idle after being off for about 2 or 3 hours...about 37-38 after driving to warm temperature
53 driving down highway at a little over 2000 rpm
58 under heavier load 3500 up to 4500 rpm

Also, I cleared the CEL after I installed the manual gauge and left the sensor plugged in (to the wiring harness, but not in the motor), and the CEL never came back on during 45 minutes of driving, and no low pressure warning (even though the sensor wasn't even plugged in to measure any pressure at all!!!). Normally, the CEL would have came back on within 5 miles of clearing and driving it. Picking up a new sensor in the morning, as it seems that is the problem. PHEW!!! Breathing a HUGE sigh of relief...since oil pump was $1,600.00 for parts and labor!!!

**elejes** · 08-04-2012

My 07 (non supercharged) grand prix started acting weird also. My family and I went on vacation and noticed the ”low oil pressure” sign turn on. Checked the oil level and read fine. I had changed the oil a week earlier before leaving on vacation. Anyway, I stopped at a local auto parts store to pick at a dudes brain about the issue and I informed him I had already traveled over two hours since it went on. We decided it might be a faulty sensor and I took the risk to continue heading home. The light never went on again and we got home safe, (thank God). The car is running fine with no noticeable sounds.
Does anyone know what the issue could have been? How can I tell if the oil pump is failing? Is it hard to install? I noticed the oil level was about 1/2 a quart over on the dip stick, would that cause an issue? Any help would be appreciated.