2011 Silverado 1500 5.3l Code P0521

[Dylan Paetsch]

Hey, so ive seen this posted a few times now and im aware its a common issue but i thought i wouidl dig it u again since i dont see anything recent on it or specific to my issue... 

 

Here goes... (excuse my grammar/spelling errors)

 

I have a 2011 Silverado 5.3l Crew Cab with... (drum roll) an oil pressure issue!  What a suprise.  Code p0521 "oil pressure performace".  It initially happened about 5 months ago in the summer and the pressure zero'd out after driving a short distance.  I took it in, oil pressure was fine but instead of doing the inevitable of changing the sending unit and screen we decided we would try replacing the oil (it was overdue and pretty dirty) and also do an engine flush to try and get rid of the crud.  This actually worked!  Oil pressure hovered around normal (275kPa/40psi) when in idle, after running for a bit.  No CEL.  I drove it for a 4 or 5 months (im still about 2k away from my recomended oil change) and then we had an EXTREME cold snap where i live.  Upwards of -40C with the windchill for an extended period of time (it was hell).  Hopped in it one day to go for a rip an noticed the pressure drop... and drop.... and drop.... annnnd CEL..... and 0 oil pressure.... alarm.  it would do this everytime i drove it, even just heading up to the store quick, it wouldnt take long until it eventually would just hover around that 1/4 mark (137kPa/20psi).  I decided to have the sending unit and screen replaced.  Got a call back, they put an actual reading on the pressure... good, changed the sending unit AND screen... good, cleared the CEL... good.  Started it up to take it home, pressure read higher than it did, but it had been sitting outside, cold.  Parked it, woke up the next morning to take it on the highway, didnt even get out of town.... CEL.  Warm oil pressure while idling roughly 137kPa/20psi.... increases a bit at higher RPM and highway speeds, but not much. Ive been driving it about 4 or 5 days now, no change.  It doesnt go into alarm, at least witht he distances ive taken it but the pressure remains low and CEL

 

SO... the infamous P0521 error = replace oil pressure sending unit seeand screen ms to be incorrect in this case.  Ill state some obvious facts before asking wtf is wrong with this thing to weed some things out.... 1... yes, ive checked the oil, its fine.  Perfect level and doesnt appear dirty. 2.  Engine temp has always been normal  runs at about 100C/210F once warmed up and idling/driving.  Never has it increased.... 

 

What im getting at here is that im fairly certain (i think?) that the engine is not starved of oil, the levels are fine and the engine isnt overheating.  It seems to still be an issue with the sensor sending false information to the engine.  But why?  Ive heard to check the Ohms on the harness to the sending unit?  But i cant seem to get much information on that.  Is there anything else it could be?  Im leaning possibly towards the fact aswell that i may have waited to long between oil changes and i have alot of buildup in there from doing so.  Are oil changes and engine flushes going be something i will have to do more regularly now as a result?  I guess that wouldnt be the end of the world... 

 

Anyway, any feedback would be awesome,  Thanks in advance.

 

(the pics posted here are of the code (duhh) and the other is of my dash idling after driving for a bit/warmed up)

[Supreme Pizza]

I would say that you are having some sort of oil pressure problem.

 

I would not run the engine for more than a few seconds with the gauge reading 0 oil pressure.

 

You mentioned that your not overheating, which leads you to believe you have good oil pressure.  But if you overheated because of no oil pressure - you would need a new engine afterwards.

 

You would not want to be driving at all with 0 oil pressure.

 

If you drive around for several seconds with no oil pressure, and it actually has 0 oil pressure, then you will drastically reduce the life of your engine.

 

If you want to disregard the electric dash gash gauge, that's fine, but I would install a temporary manual gauge and run it out of the engine bay and tape it to the hood so you can see it while driving.

 

In case you haven't already guessed, I'm of the opinion that oil pressure is extremely important.

 

If I was driving down the the highway and saw 0 oil pressure, then I would immediately look at the tachometer. If the tachometer said anything other than 0, then I would click the ignition off, turn on the right hand turn signal, and start looking for a way to coast off the side of the freeway.

 

If the oil level was full, I would call a AAA roadside assistance and have the rig towed back to my place for further diagnostics.

 

 

The next step is to 100% confirm what the oil pressure is - before driving the vehicle anymore, even if its just a bad stepper motor.

[Huckleby]

I had the exact same problem.  I was running  Fram oil filter and read somewhere to change to the AC Delco filter.  I did and it fixed my issue.  I think the Frams must be a little too restricting.

 

[richard wysong]

they used to have a display on the counter at my local parts store of a Fram oil filter cut open inside was a Japanese tuna fish can with the label still on it, I'm sure they have changed their manufacturing methods since then but you have to wonder. Walmart sells ac delco oil filters dirt cheap