high mileage oil for an older turbo car

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Originally Posted By: dave1251
Originally Posted By: firebird72
thanks for the suggestions. im not really asking which brand or weight oil to use, more concerned about the turbo, ultrafanUK mentioned the concerns, a turbo has an oil seal around a shaft that spins very high rpms, im not sure if a HM oil will be good for that if it swells the seal.

the engine has great compression & doesnt consume any oil, also all other gaskets are new & the heads were rebuilt a few years ago with new valve seals, so the high mileage isnt needed for other gaskets & seals, its just the rear main seal that drips a bit.

if there is any question about the HM oil & the turbo i will just use a quality conveentional oil or maybe a blend & deal with the minor seal leak as i have for years.


This is my opinion. There are high ester content PCMO's such as Redline and Motul. There is no "caution" about using high ester content oils for turbo seals. HM oils are ISLAC GF-5/API SN certified and seal compatibility is tested for the certification.


This^. You will get no more seal conditioner than is allowed by API for SN rated oils. It may be towards the upper range of that spec but not more.
 
Old school oil lubrication for that journal bearing should have at least a 40 wt oil to wick away heat. My recommendation would be M1 HM 10w40 or if you have no noticeable consumption or leaks, M1 15w50.
 
thanks again for the info. i wasnt aware the seals were metal in the the turbo, i never looked into that part, just assumed they were some type of material like asbestos or someting similar to a rear main rope type seal. if the turbo seals are indeed metal then thats the answer, HM wont hurt it. im ok with using it in the the engine & plan to use the valvoline maxlife or another similar type HM.

as for the scary low mileage... this is a 1981 turbo trans am that has sat for a very long time before i owned it, then only driven limited miles on nice days, sometimes less than 250 miles per year as it awaited a restoration. i did that a few years ago & pulled the engine & did a complete cleaning, painting & regasket but left the internals like pistons/rods/crank because they were in excellent condition with good compression & oil psi. so the benefits of the HM oil should be worth a few more bucks. & may try some ~$5/qt synthetic to see how it does for leaks, i have a bunch of valvoline syntec SM 10/30.
 
Or keep running what your running and add LM Motor Oil Saver for the rear seal. That is if your happy with the add pack in whatever oil you've been running. T5 and LM Motor Oil Saver would be a good choice, if looking for another option.
 
Originally Posted By: supercity
The turbo seals in a 1981 turbocharger will be a mechanical design, made of metal, you're not going to swell them with oil. Turbo seals are not like crank or cam seals.


Correct as they are like piston rings, BUT about half of the oil leaks from a worn turbo are from the oil feeder or return oil pipe connections and some of those have oil seals.

If the turbo area is causing oil leaks when the vehicle is driven at speed, then the leaks are probably from the oil feed or return joints. If the leak happens even at low power then although using a thicker oil should help, only the leak stoppers in a good stop leak can help. Using an HM oil will probably not help.
 
its been running cheap oil like walmart ST the last 2-3 changes since it sees so few miles, i will go about 2-3 years between oil & filter changes & thats always under 1000 miles total. its time for a new filter & oil & just thought of trying something different.

the turbo was rebuilt before i bought the car & has low miles on it since, was never abused or overheated so im hoping there is no coking. & no leaks at all, i want to keep it that way.
wink.gif


thanks again
 
Originally Posted By: firebird72
its been running cheap oil like walmart ST the last 2-3 changes since it sees so few miles, i will go about 2-3 years between oil & filter changes & thats always under 1000 miles total. its time for a new filter & oil & just thought of trying something different.

the turbo was rebuilt before i bought the car & has low miles on it since, was never abused or overheated so im hoping there is no coking. & no leaks at all, i want to keep it that way.
wink.gif


thanks again


The turbo lubrication technology of this era is what gave the reputation for coking so you really do need to drive it easy for the last 10-15 minutes of your trip before putting it up. Depending on the oil pressure and the built up heat under the hood, just letting it idle for a minute before shutting it off isnt enough.
 
2 or 3 minutes is enough to avoid hot shutdown damage to the turbo bearings in most older vehicles. Modern ones have a follow on electric oil puimp.
Cold starting with your boot on the accelerator causing a sudden jump in the revs as the engine fires up is more of a bearing killer.
 
yes i always do a cool down for a couple minutes if driven hard & also drive easy for the last 5-10 minutes.

Originally Posted By: jayg
Old school oil lubrication for that journal bearing should have at least a 40 wt oil to wick away heat. My recommendation would be M1 HM 10w40 or if you have no noticeable consumption or leaks, M1 15w50.


curious what you are basing that oil weight suggestion on? the car calls for straight 30 weight oil unless driven in temps below 40* then it calls for 10/30. back in the 80's GM's solution to avoiding coking was thicker oils but todays oils are much better & most all 10/30 oils will be ok for street use. i live in the midwest & the car gets driven or started in 40* & below days, the engine has very low miles & zero consumption or burning... so please explain why i would want or need a 10/40 or expecially a 15/50 oil for this car??? also, why does thicker oil "wick away heat?" always read that thinner oils, to a poaint, are better for coooling since they flow better around bearing etc... flow equals cooling, not thickness.
 
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Originally Posted By: UltrafanUK
2 or 3 minutes is enough to avoid hot shutdown damage to the turbo bearings in most older vehicles. Modern ones have a follow on electric oil puimp.
Cold starting with your boot on the accelerator causing a sudden jump in the revs as the engine fires up is more of a bearing killer.


It really isn't though. In an older vehicle that is water and oil cooled then yes but the idle oil pressure on a strictly oil cooled turbo BOP that isn't enough to avoid coking. I've had so many old school turbo vehicles and I've learned the hard way on tricks to make them last.
 
Originally Posted By: Brons2
I would also be one to yank the novel Pontiac turbo motor and put in an LS engine, but that's just me
wink.gif



absolutely not! im a diehard pontiac guy, no crossbreeding! the LS is a nice motor, but putting one in a classic car isnt my thing, i will buy a 4th gen t/a if i want an LS. for my 2nd gen f-body cars i keep them all pontiac. especially if they are #'s matching original cars. this turbo t/a is actually a daytona 500 pace car, 1 of 2000 made... its keeping its little turbo v8.

i will probably go with maxlife 10/30 this time since its a blend & has good reputation for helping leaks. but may consider some of the other HM brands too.
 
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If you want to go Maxlife on an obvious low mileage non- daily driver, I recommend you step up to the Maxlife Heavy Duty Diesel 15w40. Red gallon bottle available even at Walmart. Zinc level is very high and it should be fantastic for heat management in that motor.

Thanks to hollnagelc for the VOA:
Untitled_zpsztb8kd43.jpg
 
thanks for the voa jayg, havent really heard much about valvoline diesel oils let alone HM diesel oils. i wonder if they make a 10/30 version? i dont really want or need a 15/40 for this car, besides the climate im in, this car already has a high pressure 80psi oil pump & it holds 40psi at idle & 70-80+ while driving, even fully hot. when cold it pegs the needle of the 80psi gauge. cant imagine what 15/40 would be like on a colder day. just dont see the need for 15/40. i think the normal HM oils or maxlife will be fine.

i used to use the good SL rated rotella-t 15/40 in my other car with a more aggressive cam & valve spring, prior to 2007 when they changed it due to epa [censored]. now i use delo-400.
 
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Originally Posted By: firebird72
thanks for the voa jayg, havent really heard much about valvoline diesel oils let alone HM diesel oils. i wonder if they make a 10/30 version? i dont really want or need a 15/40 for this car, besides the climate im in, this car already has a high pressure 80psi oil pump & it holds 40psi at idle & 70-80+ while driving, even fully hot. when cold it pegs the needle of the 80psi gauge. cant imagine what 15/40 would be like on a colder day. just dont see the need for 15/40. i think the normal HM oils or maxlife will be fine.

i used to use the good SL rated rotella-t 15/40 in my other car with a more aggressive cam & valve spring, prior to 2007 when they changed it due to epa [censored]. now i use delo-400.


Looks like the image isnt showing up now. Here is the VOA specs for Maxlife HDD 15w40. Strong Zinc numbers. Do you daily drive this or park it outside? If not, I wouldn't hesitate to run it year round.

ALUMINUM 1
CHROMIUM 0
IRON 1
COPPER 1
LEAD 0
TIN 0
MOLYBDENUM 63
NICKEL 0
MANGANESE 0
SILVER 0
TITANIUM 0
POTASSIUM 1
BORON 3
SILICON 5
SODIUM 2
CALCIUM 1076
MAGNESIUM 1099
PHOSPHORUS 1012
ZINC 1236
BARIUM 0


TBN TOTAL BASE 8.5
SUS VIS @ 210° F 82.4
cSt VIS @ 100° C 16.11
 
Originally Posted By: jayg
Looks like the image isnt showing up now. Here is the VOA specs for Maxlife HDD 15w40. Strong Zinc numbers. Do you daily drive this or park it outside? If not, I wouldn't hesitate to run it year round.


no daily driving, its a fair weather driver & a garage queen. but again, 15/40 is too thick for any use or purpose of this car & where i live. it calls for 10/30 & is occasionally driven/started in colder temps. while it looks like a great oil, i just dont see the need for a thick HDEO in it. maxlife will be more than enough.
 
Originally Posted By: firebird72
Originally Posted By: jayg
Looks like the image isnt showing up now. Here is the VOA specs for Maxlife HDD 15w40. Strong Zinc numbers. Do you daily drive this or park it outside? If not, I wouldn't hesitate to run it year round.


no daily driving, its a fair weather driver & a garage queen. but again, 15/40 is too thick for any use or purpose of this car & where i live. it calls for 10/30 & is occasionally driven/started in colder temps. while it looks like a great oil, i just dont see the need for a thick HDEO in it. maxlife will be more than enough.


personally, i`d go with mobil-1 10W30 high millage oil.
 
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