Looking to try 15w40 in my 6.0 now...

[NattyBoh]

So I have been running 5w40, then I did 10w30 dino, and now Im back to 5w40. I think I want to give 15w40 a run for a while. Here is my thinking, without getting into it too much, diesels have been running 15w40 for years and in the 6.0 for a while too. My main concern was to switch to a syn because of the "stiction" possibility in the injectors. Many reported that the stiction went away with the 5w40 oil introduction for the 6.0s.

If I change out my oil around 5000-6000 OCI, I think I would be just fine running a 15w40 dino. What Im concerned about is the cold start up wear and tear. Is it significant? Would it cause issues? I know thicker oil causes the cold "romps" within the injectors, but I dont know if that actually equates to more wear internally...

 

[Donald]

Stick with Rotella T6 5W40

 

[sdude2k2000]

Short answer... 15w40 is fine, especially in the summer months.

Longer answer... since the 6.0L is a HEUI driven engine, oil pressures are CRITICAL to proper injector operation. Stiction by itself is typically a by-product of other things currently happening, or that have already happened (weak FICM, lazy injectors, low voltages, low HPOP pressure, etc etc etc). During the summer months, there wont be much of a difference, but during the winter months it has been largely proven that a 5w40 or 10w30 is a better option for HEUI engnies (CAT recommends lower grades as well in their HEUI applications).

Bottom line - HEUI systems, and the 6.0L to an even greater extent due to high HPOP pressures, tend to prefer lighter oils... proven by the way they shear the heck out of 40-grades. Is there a tangible reason you want to move to a 15w40?

 

[BigWrench9]

IF, you are indeed having stiction problems, that are oil deposit and NOT voltage or electrical problems related, I would try Delo 5-40 full synthetic. We have found, the hard way, that only after you run a product such as RevX or Archoil, will an engine oil keep your thimbles clean, and stiction free. In our case, the Delo maintained the "stiction free" injector much much better. The Castrol Elixion 5-30 as of right now is being tested in our fleet of class 6 trucks, and is doing quite well.

 

[turbowhistle]

I used to own a 2002 F350 with the legendary 7.3. It called for 15w40 except in real cold temps 10w30 diesel rated oil could be used. Some ran 5w40 all year. I used the 15w40 all year, no issues. With the 6.0, the recommended oil was 10w30 diesel rated oil. Although the 7.3 and 6.0 were made for Ford by International, they were indeed two different engines in many ways. To stay safe with your 6.0, I would stick with what the owners manual indicates.

 

[Clevy]

Stay with the 30 grade. The 6.0 will shear a 40 grade into a 30 grade real quickly but once it's lost that initial viscosity it holds steady,so there's no point going thicker.

 

[roadrunner1]

Originally Posted By: NattyBoh
So I have been running 5w40, then I did 10w30 dino, and now Im back to 5w40. I think I want to give 15w40 a run for a while. Here is my thinking, without getting into it too much, diesels have been running 15w40 for years and in the 6.0 for a while too. My main concern was to switch to a syn because of the "stiction" possibility in the injectors. Many reported that the stiction went away with the 5w40 oil introduction for the 6.0s.

If I change out my oil around 5000-6000 OCI, I think I would be just fine running a 15w40 dino. What Im concerned about is the cold start up wear and tear. Is it significant? Would it cause issues? I know thicker oil causes the cold "romps" within the injectors, but I dont know if that actually equates to more wear internally...


Haven't heard from you in a while, hows your 6.0?
Looking back through my UOA's I didn't see any real difference in wear metals between the 15w40 and 10w30, which is why I stayed with 10w30. The injector system prefers 10w30 during cold-starts, and I know I experience much colder conditions than you due to location but even during spring/summer when temps can be similar the 10w30 still has an advantage in the HUEI.

You already know my position as the 10w30 has no disadvantages in the 6.0, so its your call.

 

[fpracha]

Originally Posted By: roadrunner1
Originally Posted By: NattyBoh
So I have been running 5w40, then I did 10w30 dino, and now Im back to 5w40. I think I want to give 15w40 a run for a while. Here is my thinking, without getting into it too much, diesels have been running 15w40 for years and in the 6.0 for a while too. My main concern was to switch to a syn because of the "stiction" possibility in the injectors. Many reported that the stiction went away with the 5w40 oil introduction for the 6.0s.

If I change out my oil around 5000-6000 OCI, I think I would be just fine running a 15w40 dino. What Im concerned about is the cold start up wear and tear. Is it significant? Would it cause issues? I know thicker oil causes the cold "romps" within the injectors, but I dont know if that actually equates to more wear internally...


Haven't heard from you in a while, hows your 6.0?
Looking back through my UOA's I didn't see any real difference in wear metals between the 15w40 and 10w30, which is why I stayed with 10w30. The injector system prefers 10w30 during cold-starts, and I know I experience much colder conditions than you due to location but even during spring/summer when temps can be similar the 10w30 still has an advantage in the HUEI.

You already know my position as the 10w30 has no disadvantages in the 6.0, so its your call.
Cleanliness and wear of the injectors should really be affected by fuel only... how exactly does the oil grade (40wt versus 30 wt) affect the injector system???

 

[NattyBoh]

My reasoning is that the truck's injectors were built and tested ( this is on the Hartridge HA230 ) using a 40# hydraulic fluid. I know Im going to have a lot of people say otherwise, but Ive talked to a few injector builders ( aftermarket were talking now ) and thats what they've said. So what Im getting at, is that I know oil PSI, is oil PSI... But if the injector was built, tested and made to perform on that 40# oil, why not stick with it?


Im already running newer injectors ( the were 54k miles old when I first had them modded to 190cc's, not I just had them bumped up to 210cc's at 63k ). So the injectors have be cleaned, whatever "stiction" that was on the spool is removed, solenoid coils tested good, Im running a 58v FICM ( part that controls the solenoid ), so its getting more than proper voltage. I monitor more things NASA on this truck, so all the "problem" areas are covered...

I know I can run the 5w40, but the cost is what has me thinking. And also what Ive been seeing people do lately, was run Archoil with 15w40. The nano-boron technology may do more for internal lube than it does for sticiton. Though Ive ran it and Blackstone noted it didnt decrease my wear, so Im still on the fence on that. Ive also heard that running 15w40 with Rev-X or Archoil helps on cold starts, thus making the 15w40 cheaper, plus making it a little better on those cold days.

Hopefully I didnt bore anyone, this is just me thinking out loud here. On thing I did notice about the 10w30 was slightly lower ICP at WOT and at idle. A couple 1/10th's of a volt. I dont know if that is because of the thinner 30# oil or what, but everything else checked out pretty much better when I went back to 5w40.

 

[NattyBoh]

Whats up buddy, its going good. As you know or may not, Im always doing stuff to it haha. How do you like your new truck?

All in all, I do agree with the 10w30, but with people making them faster, modifying injectors etc, Im thinking the 40# for however long it lasts as a 40# will give better power etc. Eric at Innovative Diesel noticed a few 1/10's on his track time just changing out his oil at the local track one night... I doubt he would make it up and it was repeatable too. Just something that got me thinking.

 

[sdude2k2000]

While the injectors may have been "built and tested" with a hydraulic fluid in mind (which would have made more sense honestly), in the real world they are powered by multi-grade engine oils. Since the 6.0L has been out for over 10 years now, a lot has been understood through trial and (expensive) error. In regards to lubrication, time and time again UOAs have demonstrated 15w or 5w40 oils shearing down to a 30-grade within very short periods of time. It's just a reality of the stresses the HEUI system puts on the oils. Injector life has also been an issue over time with various reasons and/or theories as to why. One thing that both CAT and Ford have agreed on however, is that the HEUI system tends to prefer lighter oils under most operating conditions. This is why they both modified their oil recommendations to now have 10w30 cover the primary usage conditions and temperatures for most people (up to 90*F in Ford's case, and 104*F in CAT's). And before anyone goes and thinks "well that's just for fuel economy reasons"... CAT could give two cares about fuel economy. They care about long-term durability to help keep long-term maintenance costs down (i.e. replacing the crazy expensive injectors).

Archoil is not going to help a 5w or 15w40 engine oil stay in grade. It may assist with injector cleanliness though. I've seen the testimonials too, and folks appear to be pretty happy with it. Since your injectors are already clean though, I think the biggest thing for you is to simply run a quality CJ-4 lube, keep it changed on time, and monitor the other engine vitals. RoadRunner is probably the best long-term UOA keeper on the 6.0... and his UOA's consistently came back incredible on 10w30. His truck was stock, mine is pretty heavily tuned... and it loves the 10w30. Easily the best starting and quietest running (injector wise) lube that I've run.

Originally Posted By: fpracha
Cleanliness and wear of the injectors should really be affected by fuel only... how exactly does the oil grade (40wt versus 30 wt) affect the injector system???


The 6.0L uses a HEUI injection system (google it for in-depth details). Bottom line is that engine oil is fed into the injectors at a very high PSI to "fire them off".

 

[NattyBoh]

True.. tHAnks

 

[rufushusky]

Originally Posted By: fpracha
[/quote]Cleanliness and wear of the injectors should really be affected by fuel only... how exactly does the oil grade (40wt versus 30 wt) affect the injector system???


HEUI = hydraulically activated, electronically controlled, unit injection system. In the case of the Navistar 7.3 and 6.0 they use a HPOP (high pressure oil pump) to pressurize motor oil to fire the injectors as apposed to a distributor style injection (aka P-7100 bosch pump found on older Cummins engines) also popular at the time. Now Common Rails rule the market in North America for the most part.

http://www.trucktrend.com/how-to/expert-...n-systems-work/

To the OP, as others have said, I would run a 10w30 (heck Wally World is now stocking Rotella T5 10w30 in 2.5 gallon jugs now) and forget about it. 10w30 will cover the majority of climates you will run into. If you plan on running the truck on the Arabian peninsula or in northern Alaska then it is a bit of a different story.