Poor Blackstone report

[sdan27]

Got an unfavorable oil report back on a Ford 7.8L diesel we run in a silage truck. I've done three oil analysis on this engine, the first one was pretty bad but I fixed some stuff on the air intake and the second one came back quite a bit better. Now the third one is worse than the second even with nearly the same hours. I'm getting high copper, lead and aluminum. My silicon and insolubles are low and my viscosity seems to be what it should be so any suggestions on what I should look at? All three reports were through blackstone. Numbers to the left are most recent

Hours: 213, 214, 349

Al: 3,4,10
Chr: 3,2,9
Iron: 47,34,108
Cu: 261,113,487
Pb: 17,9,17
Tin: 1,0,4
Moly: 12,95,88
Ni: 2,1,4
Mn: 1,1,1
Silver: 0,0,0
Ti: 0,0,0
Pot: 0,2,10
Bor: 34,365,109
Silicon: 4,7,23
Sodium: 1,5,3
Ca: 1316,1576,3283
Mg: 771,436,102
Ph: 1051,1188,1226
Zn: 1300,1325,1386
Barium: 0,0,0

SUS Vis@210: 70.7,73.9,79.9
cST Vis@100: 13.14,13.97,15.5
Flashpoint: 435,435,450
Fuel%: Antifreeze%: 0
Water%: 0
Insolubles%: .3,.4,.5

Between the second and third oil changes, we began using Service Pro 15w-40 instead of Texaco Ursa Super Plus 15w-40.
Some of the additive levels are different but otherwise wear has mostly remained the same in our other engines. This engine probably only has about 1300-1400 hours on it as we replaced it with a new reman unit a few years back.

 

[dnewton3]

Couple of comments/questions (sort of thinking out loud, so to speak).

It would be helpful to keep the same lube choice, at the same interval; takes some of the variability out of the UOAs.

I don't see where your AL is out of whack; seems OK to me. Your Fe and Cu are certaily high. The Pb is also questionable, from my perspective. On the plus side, they are coming down. But considering that you nearly cut the OCI in half from the first UOA, the "ppm per mile" is moderately steady. Your wear came down because your sample exposure came down. Had you continued on the same 350 hour OCI/UOA, the successive numbers might have been just as high.

Reman'd engine? Quite possilby something was done wrong. Your high Pb and Cu might be pointing towards improper bearing install, improper boring alignment, etc. Not that it's a given, but certainly a possibility. I am not familiar with this engine; is this a turbo'd engine? If so, was the turbo reman'd as well? Did you get only a short block exchange, or long block exchange, or a total engine exchange? Putting a worn turbo back on a "new" engine might allow turbo wear to creep into the UOA. But obviously this is only applicable if there is a turbo involved.

How does this compare to any other "universal averages" for that type of motor? Does Blackstone have any comparable UOAs of that engine with similar exposure? With this many hours, we certainly cannot expect this to be "break in" wear numbers; way past that point.


Are your OCIs @ about 225 hours? Just a rough equivilant of 10k miles? Perhaps you're pushing out the OCI a bit long? What is the recommended OCI in hours per the reman' company? How many hours are spent idling?

Everything else looks decent, so we can't blame coolant, fuel or dirt intrusion. Vis stayed in grade. Insolubles were moderate to low.

If you rule out the external contributors (fuel, dirt, coolant, soot, etc) then the only reasonable conclusion is that there might be an issue with the quality of the reman itself. I'm not saying this is a golden guarantee, but it certainly points to a possible explination.

 

[sdan27]

The engine does have a turbo. I was not around when they swapped engines but I would guess, just from past experience, that the turbo is the original. I've usually seen remans that you have to swap the exhaust manifold and turbo from the original engine. I was thining of pulling the intake off to see how tight the impeller shaft is yet. Might pull my valve cover and check my valve adjustment too for now. Blackstone has univeral averages on a oil change of about 500 hours so we're well below that. The truck does see a lot of idling and low speed operation. A lot more than an on highway truck would. Do you think the levels of Cu, Fe, and Pb are all coming from the same source? My first thought was bearings but, reading posts on this forum, seems like I'd also see higher Tin and Al. This truck also has an air compressor which is similar to a small engine in itself but that was replaced after the engine was. I replaced it because it was getting worn out and was blowing excessive oil into the air system. It gets its air from the engine intake which is already filtered. Do you think it would be worth it to drop the oil pan and check a couple bearings? I would think with that low number of hours, there shouldn't be much wear yet but with those high numbers, has to be coming from somewhere.

 

[sdan27]

I should add too, the truck was running warm for a time until I changed the thermostats out and then still had some problems later that the aftercooler was all plugged up, not allowing sufficient air flow across the radiator either. Now that I got everything as it should be, it only runs about 175 deg. F. which seems a little cool to me.

 

[Steve S]

What is the duty of the truck. Long hard use? short hard use?

 

[sdan27]

I'd say short hard use. Short trips, just a few miles, at most, from the field to the feed pad and then back again. We have three other trucks we run like this and they don't have near the wear issues.

 

[dnewton3]

Well, I'd check the used turbo first. Bearings in particular. Endplay, clearances, etc. That could be the source of the wear metals. It's also probably the easiest to get to.

You can check the valves, but unless the guides are worn (hard to believe on such short hours on a reman) I don't see much to gain there.

If dropping the pan is easy, you can check crank endplay. Also can pull/replace one main journal at a time, and check clearances. So too can you check a few con-rod journals. Ever use a product called plastigauge? It's reasonably accurate.

I assume this is overhead valve engine with the cam in the traditional center of the v-block? If so, that's about the only difficult place to get into to check bearing wear. I can be done, but it's more difficult.

It's all a matter of how hard you want to look. You may or may not like the answer you find.

I don't think you're being any harder on that engine than other people in similar situations.

I suspect it's either the turbo, or a bad machining/assembly job at reman time. I think your engine is shedding metal due to a mechanical issue, and not outside influences such as contamination.

 

[sdan27]

Thanks a lot for all the advise. The first oil analysis I did, I figured the wear was coming from my high insolubles and silicon. So I fixed up my air filter box because that wasn't as good as it should be and added a bypass filter. Everything was getting better 2nd UOA so then was real surprised when my wear metals went back up. Do you think running the engine too warm like we did could have caused the oil to thin out too much and be responsible for the high wear? I know you could get copper from the turbo bearings but are iron and lead metals that would come from it as well?

 

[dnewton3]

I would not call your oil "thinned out too much". All three samples are very much in a safe vis range. Sure, they thinned from a VOA to UOA perspective, but in no way are they too thin. A bit of shearing is normal. I would not suspect the warm engine issue to be the cause, at least not from the oil vis perspective.

Bearings are made of many different things, depending upon application and age. It's possible that the Cu and Pb are from bearings. The iron could be from a steel part that has been abraded, obviously; possibly the turbo shaft has/is worn through a bearing on one side, and so both the bearing and the shaft are wearing?

At this point, I suspect what we know is that you have excessive wear; that much the UOA can tell you. But it's more difficult to tell where the wear is actually coming from. There are services such as Dyson analysis that cost more, but offer much more insight as well. That might be worth the investment at this point.

Past that, you're looking at tearing into the engine to find out what's going on.

 

[sdan27]

I'm hoping in another week I can get a few other jobs out of the shop and bring this truck back in to get a closer look. I'll probably end up dropping the pan and checking out a few bearings if I can't find anything else first. Do you think that the high wear numbers from the first oil report came from the increased levels of silicon and insolubles or do you think they just added to an existing problem? I kinda wonder is something changed between the second and third oil samples that caused such high wear numbers.

 

[dnewton3]

I would suspect, at a high-view level, that the numbers were not actually that much different. Your first UOA numbers were higher, but so was the exposure. On a wear/ppm basis, it's actually about the same, give or take a few points. I don't think that it's much better or worse than your first one. You simply ran the oil longer in the first sample.

I'm not exactly clear if the first UOA was shortly after the reman, or much later. During a rebuild silicon is a typical sealer; that also shows up as silica in a UOA; hard to tell them apart. But if the first UOA was well after break-in and several oil changes, then you can safely assume the silica is likely dirt intrusion.

If the turbo is easy to get to, I'd check that first. It's a used item (presumably), and it's often the first thing to get abused with dirty oil, as high rpm and silica do not make good bedfellows.

 

[sdan27]

I pulled the turbo and the shaft seemed to have excessive play just by the 'wiggle' test. Took it to a turbo shop and after they got done with it said that the shaft and the bearings both had excessive wear on them. The way they made it sound, it is not very often that the shaft itself gets excessive wear. The way we run them, several times the filter gets plugged to the extend the truck runs like [censored] but I added a wire mesh filter on the intake ducting on the side of the hood to help prevent that. I'll probably run a 200-300 hour change interval next and hopefully get a better report.

 

[addyguy]

It's pretty simple - your Silicon and insols. are way up on your last run - dirt is getting into the engine are wreaking havoc on it. Keep looking for air/dirt leaks.

 

[sdan27]

The high silicon and insolubles were from the oil sample I sent in about a year ago. The most recent silicon, insoluble levels were 4 and .3 respectively. Of the three sets of numbers, the numbers to the left were most recent.

 

[dnewton3]

Well, if the turbo shaft was as bad as you say, then I think you've discovered where the wear metals were coming from, as I had suggested.

Time will tell. Put on a turbo that is known to be in good shape, run a flushing OCI or two through the engine to remove any remnants, and then re-sample. I suspect your UOA will settle down.

 

[sdan27]

How long an interval would you call a 'flushing' oil change?

 

[dnewton3]

Gosh, I don't know. I suppose it depends upon your threshold of how much value you want to get out of the oil before you dump it.

If you simply want to get the old stuff out, and don't care about the money invested, you could OCI at 1k miles a couple of times. It's a bit of a waste of oil at that short interval, but you get to remove the old stuff quickly, and then you can start another UOA cycle. I would think two 1k mile OCIs would be a minimum.

Or, you could run a couple of OCIs at 5k miles. That way you get your money's worth out of the oil, but it could be terribly long before you can UOA with any confidence. This is difficult if you're like many BITOGers.

As a pure stab at a guess to hit the happy medium, perhaps two OCIs at 2.5k miles each? It's not so much the duration of the OCI as it is about doing a couple of flushes. You've going to want to get most of the residual wear metals out, so that they will "normalize" a bit quicker, giving your next UOA a bit more credibility. The goal is to get those out so that the next UOA will either confirm or deny the turbo as the wear culprit.

Also, this being a farm truck, you might have to make some estimates based upon hours, rather than miles.