2011 Silverado 101 Miles 2nd Check Engine Light

c0boy · April 20, 2011

Well I did not make a stink (post) about the first one, but now I'm a little frustrated. I picked up a brand new Silverado on Saturday. Saturday afternoon at 30 miles (or so) the check engine light came in. I pushed the OnStar button and had it diagnosed to code P0521. I called my dealer and they told me to bring it in. So on Monday, less than 48hrs of ownership, I drop the truck off. According to the dealer part number 12621234 (Oil Pressure Sensor) needed to be replaced and they had to order it. They installed it Tuesday and I picked it up the same night.

On my way home today from work the check engine light came on again. Just as before I pushed the little blue button and had it diagnosed to the same code.

I haven't read any posts about this sensor being a problem. I have read the long post about oil pressure. Is this something I should start worrying about or maybe GM has a bad batch of sensors? I'm used to check engine lights in VWs. Our last two VWs would throw them regularly, often enough that you just would shrug it off.

Are check engine lights this common on these trucks?

Rant over, thanks for any imput.

98 Z71 SLT · April 21, 2011

You may have some type of internal engine problem. 2 sensors, same code??? Something else at fault for sure.

Start reading up on buy-back laws in your state. Sure don't want to be stuck with a pos turd truck. I know here is WIS dealer gets 4 tries to fix a problem. You are already on try #2 at your next dealer visit...

I'll read up on P0521, will post some suggestions...

98 Z71 SLT · April 21, 2011

Ok...just read up on that dtc

P0521 engine oil pressure out of range //

Next step for the dealer would be an actual mechanical oil pressure reading. Complete upper intake manifold has to be removed for access to the engine oil pressure switch.

This code keeps re-occuring because the programmed engine oil pressure (in the PCM logic) DOES NOT resemble the engine's actual oil pressure.

Something is really wrong here...get it checked out right away...

You said the SES light came on 30 miles AFTER driving, so the engine was real good and hot...

My gut feeling says there is something internally wrong with your engine...bearing clearances, not enough oil pressure,etc...

exracer · April 21, 2011

this one is scary....If it was mine I would make them install and mechanical gauge and I would need to see the actual readings for myself......cold....then drive it and check hot.......

98 Z71 SLT · April 21, 2011

to the OP--

have you noticed any "low" oil gage readings on the dash??

SouthCo · April 21, 2011

I can only aswer your question about whether check engine lights are normal and no they are not. Good luck and keep us posted.

pm26 · April 21, 2011

I can only aswer your question about whether check engine lights are normal and no they are not. Good luck and keep us posted.

+1. I never had an engine check light come on in my truck. Is GM following in the footsteps of Volkswagen here? VW has constant problems with check engine lights coming on because they use cheap sensors made in third world countries by the lowest bidder. The customer pays for it with aggravation and money in the long run. I hope this is an isolated incident for GM, but in their never ending quest for cheaper parts, you just never know.

But as superstealth said, I too suspect that something is not quite right with the oil pressure. I have changed a number of bad oil pressure senders on cars, trucks, and boats over the years, and typically replacing the sender fixes the problem, if it is caused by a bad sender. I had a bad new oil pressure sender once - it was an aftermarket unit for a deuce and half and as soon as I installed it and started the engine, the oil came out gushing right through the top of sender which came off and I lost about a gallon of oil in a few seconds and it sprayed all over the engine. I installed the sending unit correctly, I even used Teflon tape to seal the threads so it would not leak past them. I did not count on the whole sensor coming apart. Fortunately it happened while I was watching and the crankcase holds 22 quarts of oil, so nothing bad happened. But it illustrates how a cheap oil sending unit can potentially destroy an entire engine. I hate cheap parts!!!!!!!!!!

98 Z71 SLT · April 21, 2011

To the OP---

keep this thread going, and keep us posted on what they "find" this time around

I wanna know---

c0boy · April 21, 2011

There have been no other warnings what so ever. I do plan on following up with this thread. Again I do not want to start a "bashing" but I am becoming frustrated with this. In the end it is how the dealer and GM handle this. Since the first light I called GM and they have a "file".

On another note after reading the details on the invoice for the first sensor it reads: used scan tool to observe oil pressure sensor parameter and it was within correct values.

So I guess it was cheapest just to replace a part that showed it was working correctly?

c0boy · April 23, 2011

I received a call from the service manager at the dealer. They figured out the problem by hooking up a mechanical oil pressure gauge and found the oil pressure was too high. At idle it was slightly high and at highway cruising speed it was way too high. They traced it back to the oil pump and its being replaced.

4wd · April 23, 2011

They have a chronic oiling problem, it is propagating from one year to another!...I had oil pump replaced twice under warranty,

amc31b · April 23, 2011

Oh man, This kinda makes me nervous too. I was really hoping GM worked out these kind of bugs in the later model GMT-900's. They certainly have had enough time to figure them all out and fix them! I have a 2011 LS so there is no oil pressure gauge for me to tell if something is even starting to go wrong. Not cool. Would the D.I.C. upgrade give me an oil pressure reading?

Daryl LBZ · April 23, 2011

Oh man, This kinda makes me nervous too. I was really hoping GM worked out these kind of bugs in the later model GMT-900's. They certainly have had enough time to figure them all out and fix them! I have a 2011 LS so there is no oil pressure gauge for me to tell if something is even starting to go wrong. Not cool. Would the D.I.C. upgrade give me an oil pressure reading?

I don't think it would. I think you would have to upgrade the whole guage cluster to get the oil pressure guage, unless you could still hook up a mechanical one somehow. I know my DIC doesn't display oil pressure just the oil life monitor.

pm26 · April 23, 2011

Oh man, This kinda makes me nervous too. I was really hoping GM worked out these kind of bugs in the later model GMT-900's. They certainly have had enough time to figure them all out and fix them! I have a 2011 LS so there is no oil pressure gauge for me to tell if something is even starting to go wrong. Not cool. Would the D.I.C. upgrade give me an oil pressure reading?

What? They deleted the oil pressure gauge too on LS models? It used to be standard equipment on ALL full size trucks.

What is happening here is obvious. GM is constantly looking for cheaper parts and many such parts will be actually substandard in quality. That's the only way I can explain the oil pump being defective. This is one part that should not fail and they should never compromise on quality of a critical part such as this. If they keep this up, they will perfect a throw-away vehicle. Volkswagen has already done that. Most Volkswagens become such a money pit after warranty expiration that most people will get rid of them. This is due to use of cheap parts and crappy workmanship.

ujtruck · April 23, 2011

This could be Oil Sensor + corrupted ECU Firmware (ask them to Re flash your ECU) - then, if possible monitor your engine ( I use scantool and my laptop)