P0521 - low oil pressure - how worried should I be?

[Periodic]

some history...

Car had lifters replaced under warranty in august 2013. I paid them to put a new oil pump in the car.

Fast forward to January. Pop code p0521 low oil pressure. Went to check oil, and the dipstick was broken at the bracket and had literally popped out of the block. Weldrd the bracket back to the dipstick tube got her back in the block. Changed the oil. Reset codes and have been fine ever since.

Fastforward to Thursday. On my way home from work. 25 minutes in throw the same p0521 code. Turn off hvac and radio and listen for problems. All seem ok. Drive home. Clear code.
Friday morning. I drove to work no codes (40 minute drive). Im thinking great just a fluke code. Nope...Friday on the way home it tripped again. Fak

I came home and cleared the code and inspected for any odd sounds. Nothing. This morning I picked up a new sensor from the dealer. Ugh canadian dealers charge 119 after tax. I then drove to my parents house to borrow their truck. No codes at all. The car is still their while I do some errands today.

So..from all my searching. ..many people say that it is usually the sensor...yet havent found any real world people to confirm that it has been the sensor. Most end up saying it was a problem with the oring either on pump or oil pick up tube and some of the big threads have basically had engine replaced or seriously rebuilt.

Now..if this is the case..should dealer be responsible?? Im going to hope the sensor is the easy fix for now.

[JWSDenver]

I had low oil pressure after lifters and cam replaced too. No light but just low. 2 dealers have told me that low spec is 10 psi and I am ok. Now with getting a light you are obviously out of spec but put a manual gauge on there and see what you get.

[Periodic]

Replaced sensor and still got code.

Replaced oil valve lifter filter today...we will see if that helps. Using efilive im seeing average of 36psi at idle...50psi when held at 2000rpm.

Not once did it drop below 30psi in the electric gauge. Wont have a chance to drive it until wednesday now.

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[Periodic]

Just updating my own thread...

So far Engine Oil pressure sensor and Valve Lifter Oil Filter have been replaced. Car runs good. Haven't popped a CEL yet, but monitoring it on EFILIVE I have the following results to share.

EXT TEMP was below 30F, -3C this morning.

Began logging rpm vs engine oil pressure.

On startup; 50psi at idle, 50psi while moving.

Pressure slowly dropped to 30psi at idle, 45-50psi while moving (say my first 2 stop signs)

Once the engine was warm, I was seeing pressures ranging from 12-20psi at idle, 30psi at light cruise, and 40psi at 75% throttle up to 3000rpm.

I know I need to get a manual gauge on there, but for some reason I trust the engine oil pressure sensor. It seems to respond properly to throttle application and increase pressure almost immediately with any load.

[hflores3]

I had this code issue before.
a) there are "many" bad oil sensors out there. Whomever the supplier is - should be beaten senseless!
b) if they replaced the lifters with non-dod lifters..you may need a different valley tray. I replaced mine - bingo no more P0521 code.

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[vert]

If it was the oring, I would think you would have noticed the issue right after they changed the oil pump. My dashawk would show 50-52 on start up and upper 40's while cruising 40-50 mph.

[Periodic]

Dealer attempting to replace oil pressure releif valve inside the pan. Highly doubt this is causing low pressure...since its job is to releive high pressure to afm lifters.

As always will keep thread updated.

[TooManyHobbies]

Dealer attempting to replace oil pressure releif valve inside the pan. Highly doubt this is causing low pressure...since its job is to releive high pressure to afm lifters.

As always will keep thread updated.

It could if it is stuck open by a small piece of debris.

[Periodic]

Dealer is replacing entire engine, it is being good willed through GM Canada since I am only 2 months out of my extended warranty and since the dealer was the last ones to have my engine apart only 10,000km ago. Just a minor dispute or how much of it I will cover (out of my pocket), but quite frankly those details don't belong on a public forum. Again, my experience with my dealer and with GM Canada customer care have been top notch and both have expressed a willingness to help.

[Chewy]

AWESOME! That's what you want to hear! I looked at mine the other day and it sits right at 30PSI on the HSV gauge I put in when idling and warm. It jumps right up when on it though. Mine has a Melling pump though.