Engine/Transmission (1994 - 1998) If you run synthetic motor oil will it stop the turbo from cokeing

[VHolloway]

I think I got that rite cokeing the oil in the turbo

well you know where i'm going with this

will SYNTHETIC OIL play a big part in making your turbo last longer?

 

[tp0d]

if you let the engine cool before shutting down, it wont coke. (ie burn the oil in the turbo) ... . edit-- my turbo has 185k on it, all dino oil. . no play in the shaft. synth is all about change intervals

synthetic is probably capable of a higher temperature, but that doesnt mean you can shut down your engine hot, thats a bad thing.

I usually idle for 30-45 secs after I stop to cool things down. If I just pulled a large hill/etc and then stopped, I`d give her a solid minute or minute and a half...

-j

 

[Signal73]

if you let the engine cool before shutting down, it wont coke. (ie burn the oil in the turbo) ... . edit-- my turbo has 185k on it, all dino oil. . no play in the shaft. synth is all about change intervals



synthetic is probably capable of a higher temperature, but that doesnt mean you can shut down your engine hot, thats a bad thing.



I usually idle for 30-45 secs after I stop to cool things down. If I just pulled a large hill/etc and then stopped, I`d give her a solid minute or minute and a half...



-j

yep, agreed!

 

[Vaughn MacKenzie]

I think synthetics would let you shut down with higher turbo temps, but still has a vapor/flash point that will lead to coking like dino oils.

 

[JDiepstra]

if you let the engine cool before shutting down, it wont coke. (ie burn the oil in the turbo) ... . edit-- my turbo has 185k on it, all dino oil. . no play in the shaft. synth is all about change intervals



synthetic is probably capable of a higher temperature, but that doesnt mean you can shut down your engine hot, thats a bad thing.



I usually idle for 30-45 secs after I stop to cool things down. If I just pulled a large hill/etc and then stopped, I`d give her a solid minute or minute and a half...



-j

You base it on time rather than pyro temp?

 

[Forrest Nearing]

EGT is the way to do it... after pulling a long hill a minute usually won't do it on my truck!



synthetic will resist burning better than dyno

 

[Missouri Mule]

If you don't have a EGT gauge then you have to time it. If your pulling/loaded heavy or were driving highway speeds the Editor calculated by is EGT gauge that 5 minutes would safe to shut down.



Running around town I shut down right away 5 minutes coming off highway and rest areas I leave it running ( I'm usually back on the road in 5).

 

[VHolloway]

this is a cool site ESP TURBO PLUS

AND ESP LUBER:-{}

 

[cArNiVaLwOrKeR]

I let the Turbo Timer run down to 280, dont know if that is too cool.



JoeLee

 

[fest3er]

I've been cooling to about 300F post-turbo for 11 years (250K miles). Even at that, dino oil would 'gum up' the turbo now and again (it'd be reluctant to spin up on a cold start). Since switching to synth, I don't think that's happened. I doubt there's a problem, but I suppose I should check the turbo; I haven't had the intake tube off in 100K miles or so.

Synth generally has significantly higher flash and boil points. I could probably get away with shutting down at 400F, but downshifting to 2nd (auto) for the last 300 feet or so is enough to reach 300F in a minute under all but the heaviest loads.

 

[tp0d]

You base it on time rather than pyro temp?

well my EGT gauge starts at 800 so I cant use that. (aviation pyro)



I dont pull all that much with my truck, so I`m usually runnin cool



-j

 

[GAmes]

I shut down at 300 preturbo. For 12 valves I believe synthetic is a waste of money. They have way more soot than the newer engines and the reason for changing oil is to get the contaminates out of the engine. Stick with dyno, change oil at no more than 5k and the turbo will oulast you. JMO.

 

[Vaughn MacKenzie]

I shut down at 300 preturbo. For 12 valves I believe synthetic is a waste of money. They have way more soot than the newer engines and the reason for changing oil is to get the contaminates out of the engine. Stick with dyno, change oil at no more than 5k and the turbo will oulast you. JMO.

Depends on what newer engines you're talking about, the '04. 5 & newer soot up worse than most 12 valves. I did an oil sample on my '98 12v and after 15,000 miles the soot was 0. 1% but then I don't have the "fuel turned up" as much as most. The smoky tired '96 with 400K miles had 0. 4% after 5000 miles, I run Dino in that one.

 

[Flinty]

In cold climates syn is the way to go and money well spent. Dino oil and -10* F made my engine sound like a tool box pitched down a set of stairs on start-up. The engine spins freely and with little resistance on syn. That is the only reason I pony up the extra frogskins for the fancy oil.

 

[CumminsPower98]

I rebuilt my turbo at 97k due to an oil leak on the hot side. At that time it was completely clean inside except for where the oil had been leaking. I bought the truck at 67k and it had a mobile filter on it so it might have had synthetic or maybe not, no way to really know. I went to Amsoil at that time. I have the fuel turned up to about 300 RWHP, which isn't huge but its a lot more than stock. At 122k miles I started driving OTR transporting RVs. At 371K I got a little paranoid and put another kit in the turbo. It really wasn't that bad but you all know how it is when you start worrying about something. Anyway at that time it was still spotless inside. I have shut down many times up near 400 pre turbo. I generally like to see 350 but as you can see it hasn't hurt a thing. I always idle for some time after pulling a big load. Here at home I pull a bit of a hill to work right before shutting down. I try to gear down and let it do some cooling as I pull in but I still see between 350 and 400 and go ahead shut down in that range all the time.



As far as soot goes I always have very low numbers but I do have a bypass filter and I don't have a heavy smoke foot either. I have run as many as 75k miles on a drain so I personally believe in the fancy oil (0. 10 soot). When you are running OTR you don't want to be changing oil every two weeks so it works well for that. I now have 401k and my last drain was 29k miles with 0. 18 soot.

 

[GAmes]

First of all, I don't doubt you get low readings on your analysis, but I doubt that the lab checks for everything that can harm your engine. I have driven OTR for 5 years transporting and have changed my oil in a lot of places, sometimes every week, and have never exceeded 6k... ... . no real problem there. I'm sort of leaning toward the advice of the experts that write for the TDR. specifically;



https://www.turbodieselregister.com/Issues/IO57_LubeOilAnalysisII.pdf



Finally, don't fall for the statement that synthetics can be costjustified

because they can be used for twice the normal oil change

interval. This is simply no longer true. The additive package,

particularly detergent, dispersant, and antioxidant levels, is the

primary determinant of oil change interval. Also consider that

extending oil change intervals is a gamble. You can monitor used

oil data to determine if sufficient additive is present to continue,

but one of the main reasons to change oil is to get contaminants

(soot, sludge, etc. ) out of your engine. Some contaminants, such

as glycol, can cause a lot of damage in a short time.



FWIW, I've never done anything to my turbo and am at about 300hp to the rear wheels also.

 

[fest3er]

... I'm sort of leaning toward the advice of the experts that write for the TDR. specifically;



https://www.turbodieselregister.com/Issues/IO57_LubeOilAnalysisII.pdf

Perhaps you should read the article a little more closely. If you do, you'll note that the authors did not test the standard 15W40 Amsoil diesel & marine lube, which is the weight prescribed for our engines. You'll also note that they tested only oils; they did not test other filters, especially Amsoil's full-flow filters or bypass filters.



It is your opinion that 6K oil changes are the only way to go, like it is my opinion that if one uses Amsoil lubes, full-flow filtration and bypass filtration one need only change the filters and add makeup oil to replenish the additives whilst employing periodic analysis to keep tabs on the engine's condition. If you are right, then long-haul truckers cannot ever possibly get 500K miles out of an oil change and every one who has claimed to do so must, therefore, be telling less than the full truth.



Folks who write for TDR are not necessarily experts, and they almost always inject their opinions into their musings. The articles had lots of pretty numbers, but were lacking data in a number of relevant areas. Were I to rate these articles on an informative-to-entertaining scale, I'd have to put the balance on the entertaining side of the scale. The articles left more questions for the informed layman than they answered. I didn't think the articles were all they were cracked up to be when I first read them, and I still don't think they're cracked up to be all that much.



It is not 'simply true' that synthetics can be run for twice the distance/time.

not. If you've come to expect your *oil* to remove sludge and soot from your engine, then you are sadly misinformed. A good oil's additive package will keep soot in suspension; preventing it from clumping together prevents it from causing rapid damage to your engine. A good oil's additive package has a high total base number (TBN) which both *prevents* sludge from forming in the first place and loosens sludge that has built up inside the engine.



Extending oil change intervals is a gamble only if one chooses not to learn about the factors involved. Can one simply pour in synthetic lube and continue using ordinary full-flo filters? Sure, if one doesn't want the engine to last very long. However, if one were to learn about lubes and filtration, one might just learn that oil does not go bad; it is only that additives become depleted over time, that filters clog up, that full-flow filters do not remove the smallest particles that can cause damage to your engine's bearings and wear surfaces. If one endeavors to learn, one might find that it only takes a quart or two of fresh oil to replenish needed additives in the engine's lube, that quality bypass filtration removes particles from the oil that are larger than the oil-bearing cushion, that quality bypass filtration can remove a number of other contaminants.



I'm not starting another oil war here on TDR; this is my last (only?) post in this thread. If y'all haven't yet guessed, these are my opinions, offered to entice you to do your own research. You readers' trucks are yours; only *you* can decide how to maintain them. By the same token, it is your responsibility to determine how you should best maintain your vehicle. It is your choice to maintain 1K, 3K, 6K, 10K or 25K oil changes or to never drain the oil. I may give a good-natured, 'Tsk, tsk' if one chooses 3K oil changes, but I always openly agree that maintenance is one's own choice.

 

[GAmes]

That is quite a response. Where do I start?



After 27 years as a helicopter maintainer/maintenance officer and maintenance test pilot I'm quite familiar with synthetic oils and oil analysis. We changed engines, gearboxes and transmissions on the advice of the test lab. Do you trust your lab that much?



I don't know about 500k oil changes in big trucks. I do know that they have a large oil tank in addition to the oil pan to hold oil, so quantity alone decreases it's wear.



I use synthetics. Royal purple in the diff and Amsoil in the trans. If I spend a great deal of time in super cold climates I put it in the engine. (no brand loyalty for that) I've never done anything to the differential other than replace the pinion seal once. I've gone through 5 or 6 transmissions. :{:{



Most of your post sounds a lot like an Amsoil brochure. I trust Cummins engineers and independent writers more than an oil manufacturer. Schaffer oil company's web site used to say that sulfur is a lubricant:--)









What do Amsoil filters remove from the oil that Fleetguard Stratopore filters do not? How does replacing less than 20% of the oil replace 100% of the needed additives?



At any rate, by the time you have bought the fancy filter assembly, the filters, the expensive oil and paid for all thos lab tests you will probably spend more for oil changes than I did in 600k miles... ..... and your engine won't be in any better shape.

 

[CumminsPower98]

I don't think my turbo problems had anything to do with my personal oil situation. It was leaking when I got the truck if I remember right. After I fixed it the first time it didn't leak. My cousin's '97 has about 340k on original turbo and no leaks or problems and he runs the same oil, filters and long drains. My problems were probably either in the manufacturing or previous owner.



I completely believe in bypass filtration as I have before and after data. I'm not an Amsoil dealer, I'm just someone who uses it and feel it has served me well. My engine stays very clean. I know standard oils can work well too but I just feel better with synthetics.



The cost was totally worth it to me for the oil and filters and being able to extend my drains. I didn't want the hassle of changing my oil every few weeks while out on the road and having to carry all the stuff needed to do it.



Also some engines use more oil then others straight from the factory, which we all know. Mine was using on average about 1 qt. /3000 miles so that adds up to a fair amount of makeup oil, which kept things in good shape. Here at home before I went on the road it was 1qt. /6000 miles. I have yet to see what it does with a lot more miles on it now that I'm no longer driving. Maybe I could have done just fine with normal oil this way, I don't know because I didn't try it. I'm not an expert, these are just my thoughts and what I experienced and I could change my thinking some day as I'm always learning.



I agree, this needs not start a war. Back to the original question. It only makes since to me that a synthetic oil will be less likely to coke the turbo at higher temps.

 

[Fordiesel69]

I researched this topic to death when I used to own an old 1983 Volvo 240 turbo. It came factory oil cooled only, no antifreeze. The common modd was to change the center cartridge to one with a coolant hookup. The reason behind this was because unlike a diesel, gassers have throttle plates. When you get done getting the EGT's to 1800, it will NOT cool down in a decent amount of time when at idle. The coolant helped the bearings from coking. I never did this conversion, I left it just like our diesels, oil cooled only.



I found that running a PAO based synthetic or Ester base, would significantly reduce this issue. At that time mobil 1 regular and extended was PAO based (2003-2004). Mobil 1 has now switched to a hydrocracked group III+ highly refined mineral oil that has alomst all the properties of a PAO but not in the coking department.



The only oil that I beleive is still PAO and suitable for our 12v's, is Delvac 1 5w-40 which is not only next to impossble to find, but very very expensive.



I would just not fear this issue, run dino oil, cool it down for a minute or two and when it goes south, get another one on ebay.