Oil Color

[MChalkley]

There are several factors to consider when contemplating changing a older engine over to synthetic. If the engine is leaking oil, especially from somewhere like a rear main seal, it will likely get worse, so forget it, unless you fix the problem first. Sometimes an older engine that doesn't leak at all will start to leak when you change over because the distillates in petroleum oil evaporate from the gaskets and are not replaced, though this can usually be corrected by either tightening the bolts or replacing the gasket.

At any rate, it's not a good idea to switch over without flushing the engine. Synthetics act as a detergent to petroleum residue and build-up and can cause all kinds of crud to break loose, clogging filters and such. If you flush it first, you can save yourself the cost of the first batch of synthetic.

Other than that, the benefits are identical to changing over sooner, except that you've got less left to save, of course, which should also be weighed in the balance when you're deciding.

 

[gordon]

All very good points to consider----Thanks for the info--Sounds like is best to start either with a no hour or a low hour engine to avoid side effects. Use a regular engine oil flush?

 

[MChalkley]

Um, well, no, not exactly. Most (but not all) synthetic manufacturers recommend breaking the engine in with petroleum to insure that the compression rings wear in properly. Details, details... (But you did ask...)

 

[W5FL]

I know you answered this one before Mark, but do it one more time for the new board. With a new tractor, didn't you say do the 50 hour oil change with petroleum and switch to synthetic at the 100 hour change? My tractor maintenace says change engine oil and filter at 50 hours and then at 200 then every 200 hours. It says to change the oil filter at 50 hours and then 400 hours. Also holds 11.3 quarts API Servie CD of SAE30,SAE10W-30 or 10W-40.

Question: Why do they only change the oil filter with every two oil changes?

Question: How would you go about switching over to synthetic oil with this one and the resulting oil and filter changes?

The oil at 25 hours is still almost colorless - will the synthetic tend to stay pretty clear?

 

[MChalkley]

Wen, obviously, there's not a strict formula for this, so I'm just telling you what I do. (My reason, to use the term loosely, for doing it this way, is in the archives, if you care to look at http://www.tractorbynet.com/tractortalk/messages/1/1756.html?SundayFebruary1320001209pm.) I don't change over to synthetic in a diesel until it's got 150 hours on it. Before that, I'm not sure it's broken in yet.

The oil change with no filter change is generally a function of how long they think the petroleum will last vs. how much dirt the filter should hold compared to the amount of dirt that should get into the engine. Conversely, I frequently change filters on cars I put synthetic in (if I don't have a bypass filter on it) in between changes of oil. It's because of the difference in the longevity of the oil. Just because the oil will last longer doesn't mean there's less dirt getting into the engine. So, even if the oil lasts longer, you still have to change the filter at the same intervals to keep it clean. The synthetic won't in and of itself stay any cleaner than petroleum. It won't darken from age, so it will appear to stay cleaner, but it's the filter's job to keep it clean.

I've been doing some thinking on the carbon that turns the oil in some diesel engines black immediately and takes a lot longer in others. It's pretty certain that in some engines, synthetic oil doesn't get black as quickly, so there has to be some explanation for it. Everyone I know of who's noticed this had a relatively new engine. I think that, in new engines, the synthetic helps maintain a better seal between the compression rings and the cylinder wall, preventing some of the carbon blow-by that would normally occur. This would have quite a basis in fact because synthetic doesn't burn as readily (try heating a little of both in a couple of frying pans, if you doubt, but don't use your wife's good ones - or, if you must use one of her good ones, make sure you put the synthetic in it /w3tcompact/icons/wink.gif), thus doesn't form carbon as readily, and would be able to maintain a seal a lot better.

So, in direct answer to your question, I would change to synthetic at 150 hours, changing the filter at the same time, then change the filter at least every 400 hours. I would either change the oil every 400 hours or use analysis to prolong the change until the lab says it's time to change it.

 

[W5FL]

Tell me more about the oil testing.

What do you send in and to whom and for how much? What kind of data do they send you and does synthetic oil wear out in a pretty certain time?

The reason I ask is that the dealer is doing this analysis for me for free at the 50 hour oil change and if I go to synthetics later I would like to continue this analysis if it makes sense to do so.

One more question. Do you have to rinse the old oil out if you change at 150 hours? How do you do that and with what?

That was two questions. /w3tcompact/icons/smile.gif The dealer will do the 50 hour maintenance for me for free including Kubota oils and filters, but I really think I want to do this myself. When I do it, I know exactly what was done.

 

[MChalkley]

Oil analysis is an extremely useful tool, especially if you start early in the life of the engine, because you then have a baseline, which is very important to being able to spot aberrations. They tell you what contaminants they found in the oil (and how much), as well as the condition of the oil. I think it always makes sense to do the testing, even if you don't use it to extend your drain intervals indefinitely. For example, I noticed a spike in silicon contamination in one of the analysis reports for my Dodge Cummins diesel. I figured my foam air filter must've developed a hole in it (sucking enough air to produce 30 lbs of boost kinda exceeds the expected airflow characteristics a bit...). What I found instead was that the dealer had removed (and discarded! /w3tcompact/icons/frown.gif) my lifetime foam element and stuck an OEM one back in. (I'm not saying the spike occurred because of the replacement filter, but because they replaced it, if you take my meaning.) They can even tell you which bearings are wearing fastest (if any) because they're made of different materials.

I won't recommend any specific laboratories, but check out http://www.noria.com, which is the site of an industry educational institution. One of the links on their site is 'Vendors', which has a bunch of links. There's also some excellent info on the benefits of analysis, etc. I will say that many people who own Dodge Cummins engines have expressed satisfaction with Blackstone Laboratories. (And no, they're not the outfit that Amsoil recommends, for the benefit of the conspiracy-theory practitioners among us).

I wouldn't bother to flush the engine at 150 hours. That's one of the advantages of doing it that soon - there's not been petroleum in there long enough to form any buildup, assuming you did the required 50-hour change, of course.

Synthetic oil does not have a fixed lifespan. I know an over-the-road truck driver in Chester, VA (near Petersburg) who trades his truck every six or seven years for tax reasons. The last one he traded had only 4 changes in 7 years and a little over a million miles. The last change had almost 450k on it. They pulled the engine down when he traded it in and found that no parts had been worn enough to warrant replacing them. The local mechanics said the rings and bearings looked like they had only a few thousand miles on them. I personally think his approach is a little extreme, but you can't argue with his results. He does use bypass filtration, by the way.

 

[PaulB]

Mark - what about guys like me for whom most of my use consists of start up the tractor, warm it up, use it for 10-20 minutes, then shut her down. I add up only about 100 hours a year total, so for me changing my oil and filter at the Kubota recommended interval (and I assume Kubota assumes petroleum oil) would be changing only once a year, filter every 2 years. This just seems "wrong" to me, but that is based on nothing. Should I just bite the bullet and change oil and filter yearly, knowing I am likely throwing out perfectly good amsoil, sticking to the 100 hours regardless of how much time has elapsed? Should I do the filter at 200 hours as per the book, and the oil at that time, thereby doubling the hour interval recommended by Kubota? (Again, I assume Kubota thinks I am using petroleum, and the book recommends to change oil every 100 hours, filter every 200) For me (3 quart capacity) an oil analysis costs as much as new amsoil, so I do not think that makes sense. what do you think?

 

[Fruitlady]

With diesel at these prices, I'm feeling pretty stingy about the 5 minute warm-up period for my 1 month old M4700. Sometimes all I want to do is move the tractor about 100 yards. Do I really need to warm it up first, or if I go about 1000-1500 rpm in 4th gear will that count as the warm up period? If Mark or Bird thinks I'm doing irreparable damage, I guess I could sit still for 5 minutes, but I can't see how I could be. Thanks for all the information I've gotten lurking around here the past 6 months!

 

[MChalkley]

PaulB - Hmmm, yes, I see what you mean about the price of the analysis. My Dodge takes 14 quarts, and the tractor 6 (I think), so it's a little different. But I still think the analysis is interesting and informative, whether you use it to defer changes or not. After all, it's only money. /w3tcompact/icons/smile.gif

If I had petroleum in a tractor and used it as little as you're talking about, there's no way I'd wait the prescribed number of hours to change it - it loses too much to evaporation in that time. The synthetic has a much longer 'shelf life', if you consider sitting in the tractor unused 'on the shelf'. So I wouldn't hesitate to wait and change the oil and filter at 200, as long as it didn't take more than a couple years to post that many hours. I just have a bad feeling about leaving any oil in equipment as expensive as a tractor that long.