P0521 Code

[Mickey_7106]

i have this code that keeps coming back. Started this past weekend. Dash gauge appears to read about 20 psi lower than what i remember. i dont think it goes past 40psi at WOT. AC Delco shows these two part numbers for my vin 12673134 , 55488247 but amazon says neither one is compatable with my truck based on year, make and model. Wondering if someone could me help me with this and perhaps a number for the filter/screen?

Lastly, is there an oil pressure sensor relocation kit for these 5.3s? im sure down the road ill be having to replace this sensor again.

Thanks

 

[Geotrash]

The first (12673134) is the correct one for your truck. It will have the round connector, not the flat oval as in the 2nd one you listed. Amazon's parts engine is often off. The filter/screen is included with the new sensor. Might as well buy the special socket for the job too if you don't have it already.

There is no sensor relocation kit that I know of.

 

[Mickey_7106]

The first (12673134) is the correct one for your truck. It will have the round connector, not the flat oval as in the 2nd one you listed. Amazon's parts engine is often off. The filter/screen is included with the new sensor. Might as well buy the special socket for the job too if you don't have it already.

There is no sensor relocation kit that I know of.

Thanks, checked the oil level and was low about 2.5qts. Smh straight newb mistake. Oil pressure is back to normal now.

 

[wsteele]

Thanks, checked the oil level and was low about 2.5qts. Smh straight newb mistake. Oil pressure is back to normal now.

Not sure how long it took you to burn 2.5 qts, but I assume it was between oil changes. If it was burn and not a known leak, you might want to read this, https://f01.justanswer.com/camerontech/b2a842c0-18fc-4828-85f1-e66f6588acba_SB-10065824-9133.pdf

Also, maybe think about adding a catch can.

 

[donjetman]

Part of that GM TSB is installing a new improved valve cover to reduce oil loss thru the vc built in PVC system.

 

[Mickey_7106]

Not sure how long it took you to burn 2.5 qts, but I assume it was between oil changes. If it was burn and not a known leak, you might want to read this, https://f01.justanswer.com/camerontech/b2a842c0-18fc-4828-85f1-e66f6588acba_SB-10065824-9133.pdf

Also, maybe think about adding a catch can.

Between oil changes. Just changed the oil this am. Wasted 2qts of oil from yesterday for nothing

 

[Mickey_7106]

I have a catch can from catchcan.com. that thing is garbage! Took it off for smog this year and didnt bother to put it back on.

 

[wsteele]

Between oil changes. Just changed the oil this am. Wasted 2qts of oil from yesterday for nothing

Have you checked to see if you have the updated valve cover called out in the TSB above? Your truck didn't come with it from the factory. It can make a very big difference when it comes to how much oil your engine will be burning.

I am pointing this out as my Yukon was a particularly bad example as it pertains to the issues called out in the TSB. We ended up having to replace the pistons and rings to fix the oil burn. I got lucky as GM paid for the parts, gaskets, fluids, etc. because the engine was less than 100K.

 

[89Suburban]

Thanks, checked the oil level and was low about 2.5qts. Smh straight newb mistake. Oil pressure is back to normal now.

Damn dude I would think the low oil light would have come on before the pressure drops started.

 

[Mickey_7106]

Have you checked to see if you have the updated valve cover called out in the TSB above? Your truck didn't come with it from the factory. It can make a very big difference when it comes to how much oil your engine will be burning.

I am pointing this out as my Yukon was a particularly bad example as it pertains to the issues called out in the TSB. We ended up having to replace the pistons and rings to fix the oil burn. I got lucky as GM paid for the parts, gaskets, fluids, etc. because the engine was less than 100K.

I haven't checked, but i doubt it has updated covers. Is installing the afm shield part of making the new covers work as intended? Or is that an extra precaution?

 

[wsteele]

I haven't checked, but i doubt it has updated covers. Is installing the afm shield part of making the new covers work as intended? Or is that an extra precaution?

It is a separate factor. The conclusion the GM engineers came to was there was a chance the AFM pressure relief valve, under certain circumstances, could spray oil into the lower part of some of the bores of the cylinders, causing an accumulation of oil on the rings from the underside, exacerbating the stuck ring syndrome identified as part of the excessive oil consumption downward spiral.

It seems to be the consensus opinion, at least on the internet, that the valve cover is the biggest single improvement you can make in the area.

If you are burning oil due to stuck rings, then freeing them up (or replacing them) will be needed to fix the oil consumption once and for all. But if you are just burning oil because your valve cover is funneling oil through the PCV and back into the intake, the valve cover may be all that is needed to stop the downward spiral and correct the lion's share of the issue.

PS - The updated valve cover is model year dependent (a couple of different orifice sizes in the PCV), so if you decide to do the update, make sure you get the right one for the yr/model engine.

 

[Mickey_7106]

It is a separate factor. The conclusion the GM engineers came to was there was a chance the AFM pressure relief valve, under certain circumstances, could spray oil into the lower part of some of the bores of the cylinders, causing an accumulation of oil on the rings from the underside, exacerbating the stuck ring syndrome identified as part of the excessive oil consumption downward spiral.

It seems to be the consensus opinion, at least on the internet, that the valve cover is the biggest single improvement you can make in the area.

If you are burning oil due to stuck rings, then freeing them up (or replacing them) will be needed to fix the oil consumption once and for all. But if you are just burning oil because your valve cover is funneling oil through the PCV and back into the intake, the valve cover may be all that is needed to stop the downward spiral and correct the lion's share of the issue.

PS - The updated valve cover is model year dependent (a couple of different orifice sizes in the PCV), so if you decide to do the update, make sure you get the right one for the yr/model engine.

Awesome, thanks for the help!

 

[89Suburban]

PS - The updated valve cover is model year dependent (a couple of different orifice sizes in the PCV), so if you decide to do the update, make sure you get the right one for the yr/model engine.

This is true and stated in the TSB. Just wanted to add my $.02 shit's worth of experience, I put a '09 cover on my '07 and it did not throw any codes or seem to affect anything negatively so far. Wasn't by choice, just they way things fell together at the time.

 

[swathdiver]

i have this code that keeps coming back. Started this past weekend. Dash gauge appears to read about 20 psi lower than what i remember. i dont think it goes past 40psi at WOT. AC Delco shows these two part numbers for my vin 12673134 , 55488247 but amazon says neither one is compatable with my truck based on year, make and model. Wondering if someone could me help me with this and perhaps a number for the filter/screen?

Lastly, is there an oil pressure sensor relocation kit for these 5.3s? im sure down the road ill be having to replace this sensor again.

Thanks

Our LC9s don't run as high an oil pressure as the iron block motors. Mine idles in gear in the 20s when hot and cruising under 40, the bypass on the pump spring is 36 psi or so. Mine has the new driver's side valve cover and does not burn oil unless it spends time above 3,000 rpms.

 

[Mickey_7106]

Our LC9s don't run as high an oil pressure as the iron block motors. Mine idles in gear in the 20s when hot and cruising under 40, the bypass on the pump spring is 36 psi or so. Mine has the new driver's side valve cover and does not burn oil unless it spends time above 3,000 rpms.

Mine has always been over 40 psi while driving on the highway and about 60 psi at wot. That's why I thought there was something off about my oil pressure during the check engine light.

 

[Mickey_7106]

At idle

 

[Fless]

Mine has always been over 40 psi while driving on the highway and about 60 psi at wot. That's why I thought there was something off about my oil pressure during the check engine light.
View attachment 305631

What PID are you using for Ethanol? I can't seem to find one that works on my NBS.

 

[Mickey_7106]

What PID are you using for Ethanol? I can't seem to find one that works on my NBS.

It's built in using torque pro app

 

[swathdiver]

At idleView attachment 305632

That's some hot oil right there! Isn't your truck a 4x4?

 

[Mickey_7106]

That's some hot oil right there! Isn't your truck a 4x4?

Yeah, 4x4. It's supposed to run cooler than that? 10° over the coolant temp didn't seem bad to me