Frequent regens after switching to conventional

[oakaro68]

So 3,400 miles ago I switched from Mobil Delvac ESP 5w40 to Rotella T4 15w40 and now I'm experiencing more frequent regens.

I monitor miles since last Regen using a cts2 scanner. I was consistently getting over 600 miles on a regular basis using Mobil syn, now I'm lucky to get 400. What gives? I thought I was doing myself a favor and /finally/ breaking away from all the syn oil hype, but I'm not convinced with a bit lower mpg and more frequent regens.

Thoughts?

For those of you who follow my UOA on my truck I'll be posting results from this sample when it's due or I get too irritated with this going on, which might be sooner rather than later.

 

[gathermewool]

I'm going to have to say that it's not related.

 

[Boomer]

Are you burning any more oil with the Rotella T-4? Other than that, it is hard to see how more soot would be formed during combustion just by changing oils. Only process I can think of is burning lubricating oil off of the cylinder walls but that would show up as higher oil usage. Are you having to add Rotella between changes?

 

[oakaro68]

I've been meaning to check but have been procrastinating, I'll check it out and report back soon!

 

[mattwithcats]

I would try Shell Rotella T6, full synthetic, in 15W-40...

It just started being available....

 

[CarbonSteel]

Originally Posted by gathermewool
I'm going to have to say that it's not related.
I would agree--something else is going on.

 

[edyvw]

Originally Posted by oakaro68
So 3,400 miles ago I switched from Mobil Delvac ESP 5w40 to Rotella T4 15w40 and now I'm experiencing more frequent regens.

I monitor miles since last Regen using a cts2 scanner. I was consistently getting over 600 miles on a regular basis using Mobil syn, now I'm lucky to get 400. What gives? I thought I was doing myself a favor and /finally/ breaking away from all the syn oil hype, but I'm not convinced with a bit lower mpg and more frequent regens.

Thoughts?

For those of you who follow my UOA on my truck I'll be posting results from this sample when it's due or I get too irritated with this going on, which might be sooner rather than later.


More back pressure. Back pressure sensor is thinking there is soot. What it is is SAPS.
What vehicle and WHY conventional oil?

 

[Jimmy_Russells]

It is extremely likely you have one or more dripping injectors.

 

[edyvw]

Originally Posted by Jimmy_Russells
It is extremely likely you have one or more dripping injectors.

^ That too.
Also OP, did you change diesel station?

 

[dnewton3]

The regen algorithms have zero idea of what brand/grade/base oil is in the crankcase. You have some other input that has changed. You say you "consistently" got over 600 miles before a regen; can you provide the specific data sets? Also, 3400 miles isn't exactly a lot of using the new lube (only perhaps 8 regens?). A lot of this depends on many other factors like loads, driving conditions, OATs and IATs, etc.

 

[oakaro68]

Negative. Always use the same one

 

[oakaro68]

2018 2500hd L5P duramax

 

[oakaro68]

Originally Posted by Jimmy_Russells
It is extremely likely you have one or more dripping injectors.

I just don't think that's the case since it started dropping as soon as I changed to T4. I'm thinking there's just more pumping loss creating more soot

 

[chrisri]

Switch back to Mobil. All engines burn some oil, and even a very small amount of inadequate oil will create more soot. Some vehicles don't mind, some regenerate more often.

 

[BMWTurboDzl]

Heat soak via warmer OAT causing more fuel to be burned? Warm humid air = less density right?

 

[Jimmy_Russells]

Originally Posted by oakaro68
Originally Posted by Jimmy_Russells
It is extremely likely you have one or more dripping injectors.

I just don't think that's the case since it started dropping as soon as I changed to T4. I'm thinking there's just more pumping loss creating more soot



Well it could be something extremely unlikely (that) or it could be something extremely likely (injector dripping). I would get the truck scanned for balance rates and tested for demanded/actual rail pressure.

 

[1978elcamino]

Consider a dump an fill with Delvac 5w40 and rule out the oil as suspect.

 

[4WD]

Regardless of being oil related or not … Delvac Super 15w40 has a lower Noack and stronger properties than T6.
The Delvac 1 is a fine oil … but if you don't push it long range … pretty dang costly …

 

[edyvw]

Originally Posted by dnewton3
The regen algorithms have zero idea of what brand/grade/base oil is in the crankcase. You have some other input that has changed. You say you "consistently" got over 600 miles before a regen; can you provide the specific data sets? Also, 3400 miles isn't exactly a lot of using the new lube (only perhaps 8 regens?). A lot of this depends on many other factors like loads, driving conditions, OATs and IATs, etc.

I fallowed regeneration cycles on my BMW X5 35d using Carly OBD. With Mobil1 ESP Formula 5W30 always had less frequent regeneration than any other BMW LL04 oil.
That M1 though had by far lowest SAPS levels and NOACK.

 

[oakaro68]

Originally Posted by Boomer
Are you burning any more oil with the Rotella T-4? Other than that, it is hard to see how more soot would be formed during combustion just by changing oils. Only process I can think of is burning lubricating oil off of the cylinder walls but that would show up as higher oil usage. Are you having to add Rotella between changes?

Just checked it today, oil level is spot on.