P0520 Engine Code

Discussion in 'GM Powertrain' started by adam0285, May 28, 2011.

  1. adam0285

    adam0285 Rockstar

    I'm down to one trouble code to get rid of until I get that awesomely orange picture of an engine off of my instrument cluster. The code is P0520 and the wording is "Engine Oil Pressure Sensor/Switch Circuit Malfunction". I was wondering if anyone had run into this issue before and could give me some help as to fix it. Any and all help would be much appreciated.
  2. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    Have you check the connection at the oil pressure sensor. Maybe it was loosened when the heads and cam was installed. I would get some CRC electrical cleaner and remove all the sensor wires and spray and clean them. Sometimes when those wires are disconnected for work on the engine they get some dirt and grease in them so they don't make a good connection. This is easy to do and MAY be the problem.

    ---------- Post added at 08:23 AM ---------- Previous post was at 08:14 AM ----------

    I see you have the TEA heads on your 5.3. I was wondering how they fit as I've read that the 5.3 cylinder bore was to small for a 2" and larger intake valve?
  3. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    And if you clean everything and it still isnt repaired then there is chance that the Pressure switch went out, and its time to replace it.
  4. adam0285

    adam0285 Rockstar

    I will check those connections today after I get home from work. As for my heads, I had them built with a 2" intake valve and a 1.57" exhaust valve at the recommendation of the tech rep I spoke to there. He said I shouldn't run anything bigger than 2" because I would get a shrouding effect from the intake valve being too big. I've been happy with them so far.
  5. adam0285

    adam0285 Rockstar

    One question I had about those wires, where are they? I've been having a heck of a time finding any type of wiring diagram that I a) I understand and b) shows me where they are. Any help I can get would be awesome.
  6. adam0285

    adam0285 Rockstar

    Alright so, cleaned all the electrical connections to the Oil Pressure Sensor - no change. Changed the Oil Pressure Sensor - no change. At this point I'm almost ready to give up and take it to the shop and let them figure it out. Any last minute words of wisdom?
  7. 98Hotrod98

    98Hotrod98 Rockstar 100 Posts

    Might be obvious but did you reset the computer by pulling the battery cable after you cleaned everything and replaced it?
    These oil sensors tend to go out quite often these days. They are only about $50, but are normally hell to get to.


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