2006 F250 6.0 Powerstroke UOA -semireposted

[Kleetus]

Somewhat new to the forum here... I've been a member, reading, just not many posts.

So I understand that the 6 liter likes to chew on it's oil, I would tend to agree with that, as I've ran 5w-40 syn from a couple vendors and even 15w-40 syn as well. Where I'm confused is the statement of 'shearing down to 30 weight'.

Is this making the statement that 'we' should start out with 5w-30 or 10w-30 or 15w-30 (I don't think that 15w-30 exists though) instead of 40?

My latest oil changes have been with royal purple oil, the 15w-40 worked well enough in the summer, but the motor lacked snap or crispness in the winter is was like driving a bus, I went back to the 5w-40, and it seems good, winter and summer.

Now... on to the shearing... at around the 5k mark, no matter what oil I'm running, I really seem to notice more ignition noise and more vibration from the engine. So, assuming the oil has been 'sheared' to 30w, wouldn't starting at 30w give the same noise and vibration levels at the beginning of the change as it would at the end since it's starting and presumably ending at the same 30w viscosity? By that logic, would it not theoretically be better to start at 50 and let it chew down? Something doesn't make sense.

I haven't ran any 10w-30 through it yet, and will likely do another 5w-40 RP run since I still have some remaining. It doesn't burn any appreciable amount of oil, but based on the noise and vibration levels, I'm really not that inclined to push to 7.5k or 10k based on what I FEEL, though I agree, the iron and other wear indicators show it to be just fine, and likely could go longer... so what the heck is it I can hear and feel, but can't seem to quantify analytically?

Here's my 15w-40 RP report

MI/HR on Oil 6990
MI/HR on Unit 76990
Date 12/27/2014
Make Up Oil Added 0
ALUMINUM 4
CHROMIUM 1
IRON 16
COPPER 2
LEAD 5
TIN 1
MOLYBDENUM 2
NICKEL 0
SILVER 0
TITANIUM 0
POTASSIUM 0
BORON 67
SILICON 3
SODIUM 4
CALCIUM 2428
MAGNESIUM 28
PHOSPHORUS 1088
ZINC 1233
BARIUM 0

SUS Viscosity @ 210°F 61.7
cSt Viscosity @ 100°C 10.7
Flashpoint in °F 405
Fuel % 1
Antifreeze % 0
Water % 0
Insolubles % 0.1

 

[Powerstroke]

Delo has a relatively new 15w30:

http://www.thisissevereduty.com/Product/
https://cglapps.chevron.com/msdspds/PDSDetailPage.aspx?docDataId=413394&docFormat=PDF

Running a 30 grade is no "louder" than a 40 grade...though IMO, I do feel the 30 grade provides a smoother running 6.0. I use the Delo 400 LE 5w30 and super happy with it...

 

[sdude2k2000]

Good UOA in terms of wear... typical viscosity shredding of a 40-weight. Royal Purple 15w40 starts at 14.8cSt @ 100*C... yours ended up at 10.7cSt... smack in the middle of 30-weight territory. That's where the term "shearing" comes from. The 6.0L uses a High Pressure Oil Pump that forces the oil under a pretty high amount of pressure for the injector firing (google search "HEUI injection system" for more info if you want).

Oh - And I'd agree that a 10w30 does not increase your engine noise at all. I'd actually say the opposite - the injectors are QUIETER with a 30-weight -vs- a 40-weight. The truck certainly starts noticeably better. My truck has custom tuning and I've noticed no ill effects whatsoever... only positives.

 

[Kleetus]

Yeah, I'm familiar with the injection system, really should have been a separate oil system for the firing as engine oil wasn't designed to act like hydraulic fluid.

I'm tuned as well, nothing that crazy, truth be told I'm having more problems with that stupid midship carrier bearing on the driveshaft chattering than I am the motor.

But as an engineer, it bugs me that with fresh oil it's smoother and quieter than oil with time on it, but the popular opinion seems to be put thinner oil in it as it will be better... when my experience seems to indicate the opposite.

I do like the starting abilities of the 5w in the winter over the 15w, that's very noticeable. 10w I would suspect would be pretty close for obvious reasons. The question becomes 30 or 40.

Still got some reading to do.

 

[roadrunner1]

Try a 10w-30 and run it for the same interval, get UOA and compare the results, you won't be disappointed.

 

[dnewton3]

Originally Posted By: roadrunner1
Try a 10w-30 and run it for the same interval, get UOA and compare the results, you won't be disappointed.


x100.

The 6.0 loves 30 grades. You'll either feed it one, or it will shear down a 40 to a 30 for you.

The thinner lube most certainly reduced the "cold romp" in winter in my neighbor's PSD, and yet turned in perfectly normal UOA results. With towing his boat several times a year.

Being in PA, you can use with (this is brand specific, but I am not brand loyal) either a 10w-30 Rotella TP, or the T5. Deere has a fantastic product as well; rr1 has proof! It does not get cold enough where you are at that a syn is a requirement. Even a conventional 10w-30 would serve you well.

 

[Kleetus]

I'm partial to synthetics, maybe foolishly so, but I would HOPE they hold up better. I have synthetic in everything else I run, so far so good.

My next change I'll try the 10W-30 Rotella route. I had some 5w-40 RP left, so I'm using that for right now.

Thanks gang!