High oil pressure under acceleration

Jwhite409 · March 1, 2015

Hello, new to the forum but I have a concerning question. I have a 05 silverado 1500HD with the 6.0 and I have a K&n intake and edge evoulation programmer. My oil pressure stays normal on idle and normal driving around 275+ but when I do full throttle acceleration the needle goes all the way up to 550 on the gauge. Can this cause any engine damage ?

newdude · March 1, 2015

After some quick kPa to psi conversion (40psi driving and around 80psi wide open), it sounds about right. The engine drives the oil pump, so the higher the rpms the higher load, the more pressure it puts out. Is it possible the pressure sender or the gauge in the dash is acting up? Maybe, but those numbers sound about right.

What you don't want to see is the gauge going real low at idle, near zero. No oil pressure is bad.

oldscsc · March 1, 2015

I believe that's about 40 and 80 PSI respectively?

If the condition is indeed happening, yes, it is normal, especially in the cold. More RPMs = more oil being pumped through the same clearances = more PSI.

Keep in mind, however, the 03-06 pickups are notorious for instrument cluster stepper motor failure (the motor that moves your gauge needle). You may not actually be producing enough oil pressure to peg the gauge, but rather witnessing a failed stepper motor revealing itself.

Jwhite409 · March 1, 2015

Thanks for the quick reply fellas, all my gauges work fine I was just concerned about damaging anything with that much pressure, but now knowing its normal I don't have to worry about it when I decide to mash the fun pedal.

Gurrzt · March 1, 2015

Any over pressurization in the system will be taken care of by the "PCV" system.

DwayneJ · March 1, 2015

Any over pressurization in the system will be taken care of by the "PCV" system.

PCV has nothing to do with oilpressure, crankcase pressure sure but oil pressure is completely unrelated.

As covered the pressures you are seeing are reasonable depending on temperature and the stepper motors in these are garbage, the speedo in my stops working if I drive it say -20F and it wasn't in the garage or if I drive it for more than say 20minutes.

If whay uou are seeing is a departure from normal on your truck first I would change the oil filter at least, then if you feel something still isn't right confirm pressure with a mechanical gauge.

dantesedillos · March 5, 2015

Ya definatly could be the gauge cluster with the solenoids happened in my 03 and my buddy's 04 yukon if that's the case it's a cheap fix but either way sound about right where it should be, think about it this way full throttle=high pressure increase in most applicable parts on the truck

that lb7gmc guy "Semper Paratus"

Doug_Scott · March 7, 2015

With you being in Newfoundland, average temps there are generally a bit colder than most places. The winter temp is not that bad(around 0 degrees C), but summer temps average about 16 degrees C. What oil are you running? With those temps, you are safe to run the thinner oils. 5w30 is probably good for that, I would not go any higher than 10w30.

The pressure being at a higher level at a higher RPM is preferred over it going the other way. Inside the engine there are not any seals holding back the oil pressure directly. Closest you get is the rear main seal, but it is not exposed to the actual oil galley, it gets to see the oil that leaks around the rear main bearing.

Jwhite409 · March 8, 2015

With you being in Newfoundland, average temps there are generally a bit colder than most places. The winter temp is not that bad(around 0 degrees C), but summer temps average about 16 degrees C. What oil are you running? With those temps, you are safe to run the thinner oils. 5w30 is probably good for that, I would not go any higher than 10w30.

The pressure being at a higher level at a higher RPM is preferred over it going the other way. Inside the engine there are not any seals holding back the oil pressure directly. Closest you get is the rear main seal, but it is not exposed to the actual oil galley, it gets to see the oil that leaks around the rear main bearing.

I run 5w30 as it calls for on the engine cap, it gets a lot colder here then 0 degrees C here in the winter and we been getting really hot summers lately.

DwayneJ · March 8, 2015

The 5w-30 thing is all about CAFE not what is necessarily best for the engine and since the "30" is a RANGE a 0w-30 can the thicker than a 10w-30 at operating temps.

Based on Used Oil Analysis a particular 0w-30(usually refered to as German Castrol) performes very very well, but is getting increasingly hard to find and is splitting hairs anyway. I just mention it because based on actual measured performance this oil works better than what GM tells you to use.

It tends to be a fair bit thicker than the 5w-30 M1 evenyone mistakenly believes is magical in LT1s and LS variants. They make that assumption based on the marketting deal struck to use it in the Vettes starting in the 90s, even in the LT1s that first becan in it was never anything more than mediocre for the application, a quality product but not great for that app.

Doug_Scott · March 8, 2015

The 5w-30 thing is all about CAFE not what is necessarily best for the engine and since the "30" is a RANGE a 0w-30 can the thicker than a 10w-30 at operating temps.

Based on Used Oil Analysis a particular 0w-30(usually refered to as German Castrol) performes very very well, but is getting increasingly hard to find and is splitting hairs anyway. I just mention it because based on actual measured performance this oil works better than what GM tells you to use.

It tends to be a fair bit thicker than the 5w-30 M1 evenyone mistakenly believes is magical in LT1s and LS variants. They make that assumption based on the marketting deal struck to use it in the Vettes starting in the 90s, even in the LT1s that first becan in it was never anything more than mediocre for the application, a quality product but not great for that app.

If I am reading this right, you are saying that a can marked to be 0w30 may not meet the specs for 0w30? There is a pre-defined standard way for manufacturers to use when claiming viscosity.

0w oil is tested at -30C and 10w is tested at -20C. 5w is tested at -25C. If you test all of these at 0C they will not meet their marks for viscosity. Oil that does not have the W (for Winter by the way) in the viscosity are measured at 100C. All grades, one temperature.

Personally, I use 0w30 from Oct to Apr, and 10w30 from Apr to Oct. Using the 0w30 in the winter stops the valve rattle I would sometimes get when truck is left for a couple of days at -20C (0F) with either 5w30 or 10w30.

Essentially, 0w30 is supposed to have a viscosity of 0 at -30C and a viscosity of 30 at normal operating temps.

DwayneJ · March 9, 2015

I am speaking about viscosity @100C basiclly operating temp viscosity. All oils are tested at that and is the basis for the -30 in the oils being discussed. 30weight regardless of a Xw in front of it has a cSt@100C of between 9.3-12.5. One 10w-30 might have a cSt@100C of 9.9 and many 0w-30s have a cSt@100C up near 12.

You seem to be under the impression that 0w-30 is thinner all the time, and that is a VERY common assumption and VERY wrong. Yes a 0w will pump well at a lower temp than a 10w-30 but that means nothing about operating temp viscosity.

Doug_Scott · March 9, 2015

I am speaking about viscosity @100C basiclly operating temp viscosity. All oils are tested at that and is the basis for the -30 in the oils being discussed. 30weight regardless of a Xw in front of it has a cSt@100C of between 9.3-12.5. One 10w-30 might have a cSt@100C of 9.9 and many 0w-30s have a cSt@100C up near 12.

You seem to be under the impression that 0w-30 is thinner all the time, and that is a VERY common assumption and VERY wrong. Yes a 0w will pump well at a lower temp than a 10w-30 but that means nothing about operating temp viscosity.

I am under the assumption that 0w-30 is easier to pump at -30C than 5w-30 is. Note that I have said nothing about which is thicker or thinner at 100C. The reason they have the xW grade is because some engines have to start and run at -30C for months at a time. I thought I was clear in my reasoning for using the 0w-30 in winter. But in case I was not clear why, here is why I do this.

When it is -30C outside, my truck will occasionally 'rattle' on the cold start if I am running 5w-30 or 10w-30. Using 0w-30 does not give me a 'rattling' engine on a cold start. When it is -30C outside, and my truck has been sitting for a couple of days, I do not care what viscosity the oil is when the temp is 100C. I am only concerned with what it will be when I try to start the cold engine. I don't know how to make this any clearer.

If the oil is rated as being 0w-30, it is tested at both -30C and 100C. It should have the characteristics of a oil with a viscosity of 0 when tested at -30C, and have the characteristics of an oil with a viscosity of 30 when tested at 100C. All oils that have a xW viscosity are tested at both cold and hot temps. If there is no W in the rating, no cold temp test is done.