P06DD Oil pressure

[Jayselectricco]

I have a 2014 Silverado 4.3l 4x4 lt , I recently bought this truck and the check engine light came on P06DD.  The oil was very dirty so I changed it and the filter, however the CEL came back on.  I ran that oil for a couple hundred miles and replaced it again to make sure all that old sludge mess got cleaned out of there. Seems doing that helped prolong the time that it took for the CEL to return. I replaced the oil pressure sensor, but it did not change anything. I used an OBD reader and noticed that after I reset the code and I drive it the truck will go into V4 mode a few times then won't do V4 mode anymore and then I will have a pending P06DD code.  The oil pressure runs just above 40 when idling and goes up to 60-70 when accelerating, however at cruising it hangs around 60. I would expect it to be back down around 40 when in 6th gear and running at a low rpm, but that may be normal. From what I understand there is a 2 stage oil pump and the solenoid switches between low and high oil pressure mode.  That fact that it has a range of 40 to 70 oil pressure makes me think the solenoid is working.  I called a dealership and talked to a service guy and he said that sounded normal.  I would love to talk to someone who has a 4.3 and could tell me how their oil pressure works, or anyone that could help, thanks !

[CamGTP]

The range that it moves would be normal while driving but the oil pressure staying at 60psi while cruising means it's not working as intended. It should drop back down to 35-40psi while cruising and 20-25psi with a hot idle.

[Jayselectricco]

Ok thanks! Do you think that means that the oil pump is just stuck in high pressure mode all the time?  I guess the only way to know is to take it to a mechanic that can switch the solenoid back and forth and see if it changes right? Thanks for the response!

[Jayselectricco]

On 5/6/2022 at 7:02 PM, CamGTP said:

The range that it moves would be normal while driving but the oil pressure staying at 60psi while cruising means it's not working as intended. It should drop back down to 35-40psi while cruising and 20-25psi with a hot idle.

I just noticed today that my engine temperature does not go past 185, and is sometimes lower.  So I am guessing my thermostat may be stuck? If the oil is never getting hot then my oil pressure would be staying high and maybe be causing my code? Thanks 

[CamGTP]

Not likely, the oil doesn't have to get super warm for it to still idle around 20-25psi. Even on a cold engine my truck with a V8 using the same style pump does not run at much more than 50psi going down the road.

[Jayselectricco]

That makes sense, but do you think I have a separate problem with the thermostat? Isn't it supposed to get up to 210? Thanks

[richard wysong]

check the temp with an infrared temp gauge or just change the t-stat, fluctuation may just be low coolant level. not related to op problem. possible problem with the gauges, whats the scanner read?

[Jayselectricco]

Ok, I am going to pick up a thermostat on the way home from work today and see what that does.  The scanner I have is just a Bluetooth obd2 reader and I don't see a temperature or oil pressure readout on it.. it just gives me P06DD code... I can reset it and it and drive the truck and it will go into V4 mode a few times then will stop going into it.  I can check it after it stops going into V4 mode and there will be a pending P06DD code. My temperature never gets past 185 and most of the time is lower than that.  My thinking is that if the oil pressure changes from 40 to 60 then both oil pressure modes are working, but the overall oil pressure is higher than normal in both modes.  I know oil is thicker when it's colder and will cause more oil pressure. I am hoping my tstat is stuck open causing it not to fully warm up, and once that's fixed my oil pressure will come down some into the range acceptable to the computer. CamGTP says that the oil pressure should come on down to 20-30 psi when hot.  Is that what the 5.3 oil pressure is?  I noticed that the 5.3 uses 0-w20, the 4.3 uses 5w-30 and maybe the 4.3 oil pressure runs a little higher because of the thicker oil? I don't think the 20 or so degrees of heat I will gain will bring the oil pressure down that much. I guess it's wishful thinking that the two problems are related, but I guess I will find out if the thermostat fixes the temperature problem. I appreciate y'all's responses!

[Jayselectricco]

Well I replaced the thermostat, and drove it down the road and back, and it went up to 210 and stayed there.  Also my oil pressure dropped back to about 40 cruising, and down to 20-30 at a hot idle. Haven't seen the Check Engine light back on yet, so I am hopeful!

[Jayselectricco]

Now If I could fix that gauge between the oil pressure and temperature... it keeps using more money than it used to, to keep it pointed towards F instead of E 

Edited May 10, 2022 by Jayselectricco

[richard wysong]

I hear that, gas went up .30 here last week, it's $4.29 at the lowest places. I try to fill up before it gets down to 1/2 a tank, it doesn't hurt as bad putting $50 in as it does $100 even though it's not really saving anything

[Jayselectricco]

I know what you mean, it's about $4.20 a gallon around here.  

[Tier1parks]

@Jayselectricco I’m curious if replacing the thermostat ultimately corrected both problems for good, or if the oil pressure ever gave you issues again? I’m dealing with the exact same two problems right now. I was thinking the same thing about the stat causing my oil pressure problems as well, and now that I see you’ve dealt with the same issues I’m hoping it fixed yours and I’m on the right track. 

[Jayselectricco]

On 5/28/2023 at 8:21 AM, Tier1parks said:

@Jayselectricco I’m curious if replacing the thermostat ultimately corrected both problems for good, or if the oil pressure ever gave you issues again? I’m dealing with the exact same two problems right now. I was thinking the same thing about the stat causing my oil pressure problems as well, and now that I see you’ve dealt with the same issues I’m hoping it fixed yours and I’m on the right track. 

Hello, 

 

To answer your question ... yes and no. First of all the thermostat was definitely bad, it goes to 210 and stays there, before the oil pressure would never drop under 40 because it was never getting to a "hot idle." The P06DD came and went, and most of the time would come back when it was nearing an oil change.  I thought this had something to do with old oil causing it however I discovered that it was something different.  My torque converter went out and I was inspecting the transmission cooler lines and seen a leak, however it was not transmission fluid leaking it was oil.  I traced the source of the oil leak back and it is actually leaking around the 2 stage oil pump wiring harness and running down. So I thought Ok so the oil is shorting out the wires in the plug causing the P06DD, however cleaning it had no effect on it.  What did have an effect is putting the oil back in that it had leaked out. As long as I keep the oil level up P06DD stays gone even if the oil gets past 5k miles (I try to change it every 3-4k miles) still is gone. I can't say for sure that the oil in the connector is not still causing it, or that may be on the way. Just seems as tho I will loose about a quart every 2500 miles or so and that is what is triggering the code. Its kind of hard to read that dipstick accurately anyway. The real fix would be to change out that wiring harness and put new seals but you have to drop the oil pan to get to it, so might as well change out the oil pump and all when I break down and do it. For now I seem to be keeping the check engine light at bay by keeping the oil level right. Oh also, I did get one of those Range AFM disablers and that stops that code from ever coming on, however that thing will never go back in my truck because it caused my transmission temps to go 240-250 under normal driving, and I could pull it out and run 130-160.  Worst purchase I ever made getting that RANGE, it cost me a torque converter. 

[mikeyk101]

27 minutes ago, Jayselectricco said:

I did get one of those Range AFM disablers and that stops that code from ever coming on, however that thing will never go back in my truck because it caused my transmission temps to go 240-250 under normal driving, and I could pull it out and run 130-160.  Worst purchase I ever made getting that RANGE, it cost me a torque converter. 

Sorry, a little off topic but... That's an odd outcome. I've been using my RANGE AFM disabler for several years now and it never had an effect on transmission temps or give me any other problems. Well maybe when it was time for emission testing but that's easily solved. What did help for trans temp was swapping out the Transmission thermostat to the updated ones. Mine still seems to run a little warmer than others have reported but stays in the 150-175⁰ range. It only went up considerably north of 200⁰ when I was towing my toy hauler up a steep grade for several miles. Other than that, it has pretty much stayed at a much more reasonable temp. But taking it out and seeing lower temps would confirm that something was going on.