vroomvrooom

Just got the car not too long ago completely stock with 53k miles so I don't know how long this has been going on.

Noticed the hot 580RPM idle oil pressure is in the low 20s even hitting 19 with oil temps >210. The pressure jumps up to 30psi by 1000RPM, 40 by 2000 and 50 by 4000. Cold start is 50psi.
I have verified with a mechanical gauge and it's the same (also noticed it's a bit bouncy especially at idle).

I changed the oil as soon as I got the car from dealer fill to Mobil 1 5W30, 3k miles later I drained it and cut the filter. The oil looked fine, the filter had a bit of stripper glitter and 3 pieces of shavings that were grey in color and non ferrous.
I pulled the filter again after 70 miles to gong one piece of aluminum colored shaving also non ferrous in it.

The car runs perfect, doesn't make any noises that I would consider abnormal. GM won't look at in under warranty until it shows up on a tow truck.

How thick is the layer of the bearings that is silver in color? Is there anything else that can be giving off these shavings?

Thanks for your help.

smitty2919

What year car will help people help you.

Rule of thumb I have heard and gone by is 10psi for every 1000rpm.

And oil pressure is only the resultant vanlue based on the amount of restriction in the oiling system along with water temp/oil temps. Thinking of it this way can help some people diagnose possible low oil pressure issues.

I had been getting a clogged radiator and would see 230* at autocross in my 95 LT1 which would bounce around 10psi at idle. All I did was upgrade my radiator and added a EWP, now my temps don't get above 195* and oil pressure is 15-20psi. So my root cause was water temps getting to high and not allowing oil to stay cooler.

Your readings don't sound too alarming to me.

vroomvrooom

I understand that pressure is affected by temperature. My oil temps don't normally go over 210 even on hot days, after autocrossing or road racing when the temps go higher, I see pressure dip down to 17. I have compared to other vehicles that see 30-35psi at hot idle, mine is low. The metal in the oil filter doesn't help the case either.

smitty2919

Again...what car do you have? What do you have done to your car?

Are the other cars the same setup as you? Same oil pumps, same oiling systems etc?

vroomvrooom

It's a stock gen 2 CTS-V. The other cars I'm comparing to are also stock gen 2 CTS-Vs with similar mileage and the same weight oil.

farmington

iTrader: (14)

sounds like on the low side of normal. wouldn't worry about it.

vroomvrooom

I wouldn't be concerned if not for the shavings in the oil filter.

1 FMF

iTrader: (1)

google babbit bearing for info on how they are made and what layers of material there is.

theres no point in worrying about it till you have a real problem. right now u dont have anything close to a problem. oil pressure depends on oil viscosity and temperature but also oil pump speed which is engine rpm. 800 rpm vs 600 rpm idle is a 33% increase if u do the math so u should expect a quick increase in oil pressure. it is normal to have 15 to 20 psi at hot idle 600 rpm especialy with 5w30 oil.
if youre in northern half of country and see below 50° cold start temps then run a 10w40 or 5w40. if your in hot climate especially southwest where its always above 80° and u get in stop and go traffic your oil temps will get very hot not moving and low rpm and low viscosity 5w30 is not good, here you want minimum 15w40 and probably 20w50 you shoild be worried about durability not fuel economy.

vroomvrooom

I have never worried about fuel economy, otherwise I would have bought a Prius. GM spends a lot of money to specify an oil viscosity and I refuse to change it. A thicker oil won't fix anything, my oil temps don't get over 210 with my driving. I would think that shavings are a "real problem" or is this like the GM dealership and it's not a real problem until is spins a bearing?

00SlvrSS

Oil pressure actually has a lot to do with bearing clearances. I don't know why people hardly ever consider that. And yes it is a problem. Lt1 model engines have a much larger bearing to crank clearance than an LS. So there's no comparing there. The bouncing needle at idle is what you don't want. The metal chunks and shavings is what you don't want. That is very premature for that many miles. I would worry instead towing my car off the road to the GM shop ( or any shop) and pay for some very serious damage.

00SlvrSS

And also pressure changes temps of oil. The lower the pressure, the less temp, the lower the break down rate of the oil. And vice versa.

1 FMF

iTrader: (1)

how do you know this?

vroomvrooom

They don't just arrive at a number by method of rectal extraction. There's a good amount of engineering and testing behind it.

farmington

iTrader: (14)

days and days in the dyno cells. trust me on that one. They don't just pick an oil and say, that one should work. Its an engineered and tested package.

1 FMF

iTrader: (1)

how much? how many degrees (in Fahrenheit or Celsius) will the temp of the oil change based on how much difference in oil pressure?
Since you said that, I would like to know.

1 FMF

iTrader: (1)

show me the engineering and testing then... since there's a good amount of it.

I'd like to know how you can state this, what qualifies you to state that?

vroomvrooom

There is a physical relationship between pressure, volume and temperature, usually when it comes to engines I'd consider it the other way, the hotter the oil the lower the pressure, however higher pressure means more restriction which creates heat.

1 FMF

iTrader: (1)

yeah, and is this more pressure => more heat at all significant ?
are you saying you should only have 40 psi oil pressure and not 60 psi because that will raise oil temp from 200°F to over 270°F and be a problem.....
since you said that and are making an issue of it I'd be interested to see it quantified....
but on the other hand i just saw you said it's a CTS-v so i really don't care, and i didn't really care to begin with.
best of luck

vroomvrooom

I don't think so, in this situation, the temperature is what will cause pressure to drop, the other way around would have negligible effects. I was just justifying someone else's point.

Firebrian

There is a reasonable amount of variation even with the same "weight" oils. If cars you are comparing against are the same as yours and run the exact same brand/weight/spec oil, then I'd agree. You are getting a reasonable pressure rise for each added 1,000 rpm. If your 6,000 rpm is up at 60 psi or higher it's probably ok though 65-75 psi would be better. You should be able to find what estimated oil pressures are for your engine using factory recommended oils. I'd agree that going to a significantly higher viscosity might actually cause more problems. A higher oil pressure doesn't mean you're getting optimum flow. The fact that your oil pressure is rising steadily up to 4,000 rpm is a sign of good flow. Check to make sure it continues at 5,000 and 6,000 /65+ psig (or whatever red line is) . If you get this, it probably means that a good 30 wt is all you need.

The car manufacturers also have to balance CAFE/mileage standards vs. optimum engine longevity/power. No doubt there's a lot of engineering that goes into the equation. And then the marketing team gets involved and all that "engineering" gets diluted down. Then you have the individual buyer who is not "average." Not every car out of the factory is average either. You might have a "Friday" built engine and/or car. The engine and oil were designed to handle a wide band of ambient temperatures, driving habits, and factory builds, etc. There's a good chance that the recommended factory oil is not the ideal one for your particular usage. The recommended stuff will probably do very well for most anyone. If you want "ideal" then there are other options, especially on performance cars.

With your car still under warranty then you're on the 5W-30 until it expires....otherwise I'd recommend looking at 0w-30, 0w-40, and even 5w-40 oils. The M1 5w-30 is a mid-range 30 weight at 11 cs/100 deg C. While it's supposed to fine for occasional track use, I'd be more comfortable with a slightly higher viscosity and hths (12-13 / 3.5-3.8). For now, I'd get the best 5w-30 available. I do note that the M1 5w-30 High Mileage version does give a bit more viscosity and hths (11.7 / 3.3). Pennzoil offers a Platinum Ultra Euro 5w-30 spec that meets A3/B4 and it's probably a thick 30 weight. It might be hard to find but it's probably closer to a weak 40 weight like the Castrol GC 0w-30 Euro (12.1 / 3.5). Do you have an oil temp gauge on your vehicle or is that 210 deg F just the coolant temp? You can still get localized high oil temps even with normal looking coolant temps. In any case you should get an oil analysis taken and sent off to the lab to verify if you really do have metal and exactly where it's coming from. What you don't know is how that car was driven and maintained for the 50,000 miles before you got it. Lots of variability there. If an oil analysis shows excessive engine wear particles then you have more ammo vs. the car dealer/factory warranty.

Seems like there are a number of threads on the internet about fluctuating or low oil pressure for the LS2/CTS-V. The guy below had a wandering relief valve. Other mechanical issues "could" be causing your symptoms: oil pump, pick up tube, etc.

http://www.yellowbullet.com/forum/sh...php?p=12113334