CJ-4 oils not holding up?

[cartmanea]

I was wondering if anyone has more info on this topic. It seems the new low emissions stuff isn't holding up as well as the previous spec. My dad drives truck for a certain large shipping company with brown trucks.. They use Delo 400 in all their trucks and do the 15 gallon oil change every 20k miles. Yes I know, thats a long time to run dino oil, but there is 15 gallons of it in there and these trucks never even cool off. 20k miles is only 2-3 weeks between changes.

The engine manufacturer is recommending they reduce their change intervals to 15k, which is understandable, but I thought it was interesting these problems started surfacing with the switch to CJ-4 oil. Please post your comments!

 

[Quest]

what problems are you referring to? low emissions stuff (as in what? low sulphur fuel? additional emissions device in diesel trucks? fuel pump failure? seals blown?)

Sorry, can't provide answer unless you can provide us with details.

Q.

 

[MGregoir]

It's probably due to the reduced TBN of the newer oils due to sulfated ash limits, and nothing more.

The oils themselves are almost the same base oil wise, it's a reduction in detergency and certain anti-wear additives that is making the difference. Unless it is synthetic oils like Delvac 1, which I imagine has a good shot of ester to help with solubility, UOAs will come back and say TBN low, insolubles high, and to change the oil.

A bypass system may help significantly extend oil life if it's an insolubles issue.

 

[cartmanea]

Quest, forgot to mention, the problem was their UOAs were showing high bearing material content, rod and main bearings.

MGregoir, isn't Mobil Delvac dino oil? I'm running Delvac 15w40 in my 6.0L F250 and it sure doesn't have a synthetic price tag on it.

 

[MGregoir]

Delvac Super is conventional, Delvac 1 is synthetic.

The rod and mains thing would be a major concern and I am wondering what is making them wear like that because the oil can't "cause" it, just prevent it.

 

[Pablo]

I would love to comment if there were some data. This is the first I have of any problems with CJ-4 generically or with any one brand. In fact, what I have seen so far has been good.

 

[cartmanea]

Thats about all the info I have on it, I just wondered if anyone else had heard of the same issue.

 

[pickled]

I posted this information a while ago.
Diesel UOA CJ-4
I'm not greatly impressed with the performance of CJ-4 and the fleets that I've been working with had to adjust their OCI's due to TBN depletion issues.

 

[Stephen M.]

It is not the CJ rated oil, it is the over active EGR valve and cycling (cleaning) of the Particulate filter in the exhaust system. The oil loads with heavy carbon products and without the CJ level of oil the changes would become even more frequent.

 

[pickled]

Sorry, but I have to disagree with your post in part. The CJ-4 oils sampled from 2001 non EGR non DPF units still required a shorter OCI than when they were filled with their CI-4 + sister oil (same name just different specs). Yes you are correct that the newer units do really beat up oil. As an additional experiment we have used a CI-4+ group IV synthetic oil in 2007 Cummins ISM vehicles (with DPF's and EGR's) and the wear rates were not significantly different than the CJ-4 equipped vehicles on a ppm/1,000 mile basis...the CI-4+ actually looked a little better, but we did not have enough data points to say that it was a statistically significant difference. The main difference was that the synthetic oil held it's own past 50,000 whereas the CJ-4 petered out at 20,500 miles.

 

[PT1]

Originally Posted By: Stephen M.
It is not the CJ rated oil, it is the over active EGR valve and cycling (cleaning) of the Particulate filter in the exhaust system. The oil loads with heavy carbon products and without the CJ level of oil the changes would become even more frequent.


True, I have a client in the DPF business and that is an issue they mention frequently. There are a lot of filter component contamination issues as well.

 

[cartmanea]

Originally Posted By: Stephen M.
It is not the CJ rated oil, it is the over active EGR valve and cycling (cleaning) of the Particulate filter in the exhaust system. The oil loads with heavy carbon products and without the CJ level of oil the changes would become even more frequent.


The vehicles did not change with the change from CI-4 to CJ-4 in the example in my original post. It was on a fleet of semi-trucks and with the change in oils they are seeing a need to shorten the change interval based on oil analysis showing a lot more wear with the CJ-4 oil.

 

[wileyE]

Bearing wear would be more a function of viscosity than add pack difference. If both oils were 15w40 the bearing wear should have been the same unless there was "junk" in the oil which would be a filter issue, not a ci vs cj. IMHO

 

[Steve S]

Originally Posted By: pickled
I posted this information a while ago.
Diesel UOA CJ-4
I'm not greatly impressed with the performance of CJ-4 and the fleets that I've been working with had to adjust their OCI's due to TBN depletion issues.
Being in the industry and being able to see the results of the uoas is being in the drivers seat as far as real life info . Is it the TBN not holding because it is lower or is there more wear from the lighter or different add pack? The Rotella uoas posted seem pretty good.

 

[pickled]

Hey Steve S. hopefully you can keep those wildfires under control out there!! As far as your question is concerned the real issue we face mainly is the TBN starting points vs. the rate of depletion. Granted the rate of depletion is less per 1,000 miles than the CI-4 counterpart (i.e. Delo 400 LE for Delo 400 MG), but the intersection of the curves affords a noticeable difference (approximately 3,000-5,000 miles in my last two studies) in the end point where TAN starts going vertical. The older CI-4+ formulations also seemed to be more tolerant of EG based extended life coolant contamination than the new formulas...viscosities and TBN really move to the dark side quickly when coolant gets to the CJ-4 (I really don't understand this one based on the formulation change, but the data shift was quite noticeable)!

In the absence of coolant contamination wear metal generation (as measured via ppm/1,000 mile per UOA) comparisons afforded no statistically significant difference between CI-4+ and CJ-4 populations (tested at alpha 95% beta 15% for all you stat geeks out there). This held true when comparing paired vehicles from 1999-2007 build years with similar maintenance histories and conditions of use. We have additionally screened EGR vs. non-EGR data to see if CJ-4 reduced wear better under conditions of higher soot loading. Again we didn't see a difference in our studies. It is very rough for my fleet clients to swallow the concept that because 20% of their fleet has DPF's they bought more expensive oil to protect these new vehicles, via the lubricant supplier's suggestion of consolidation/error proofing, and now they have to drop their OCI by over 15% across the board! When maintenance labor hours, equipment utilization and material costs get figured into this equation a very large negative variance is felt by a fleet with 1,000+ class 8 trucks.

 

[Steve S]

Thanks.