CAN ENGINES BE TOO OLD FOR SYNTHETIC

[escavader]

Im from the old school,change oil and filter every 3000 and thats that.Istarted running synthetic in tractor.LIKE IT. still change at 50 hours
Then i buy the TUNDRA.Comes with it,dealer said change at 5000 and rotate tires each time instead of at 6000.Makes sense and if you think about it it doesnt cost alot more because you dont change as often.So i went with it.
So i started doing it also in wifes SUBURU .It was low mileage,and ran quieter on it.
My 98 JEEP with straight 6 has 102000 on it.Doesnt burn oil,runs like new one.Is there anything wrong with switching it over to synthetic with the 5000 mile maintanace plan?It sure is alot easier to keep track of when to do it,and not guessing when to rotate tires[do it each time]What do you think?Any problems switching a well broke in engine over?
ALAN

 

[Tig]

Over the past five years I have switched two vehicles to synthetic that were well over the mileage you mention. I have had no problems.

 

[thatguy]

On higher mileage vehicles (not sure what the cut off is) they recommend doing an 'engine flush' to get any sludge/gunk/build up out of the engine.. Otherwise the synthetic my loosen the stuff and then possibly clog the filter..

I am running synthetic in my wife 2009 Subaru Forester (amsoil) and on the tractor (Rotella 5w40, will switch to amsoil the next change).. I was planning on going to 10k changes with UOA on the Subaru, but most ppl recommend not exceeding the mfg recommendation if under warranty - so 7500 miles will be the limit..

brian

 

[aczlan]

from what I have seen and heard, no. the Volvo list I am on has many people with Volvos from the 70s (and a few older) to current cars, it is not uncommon to have 200+k on these cars and the recommended oil is Mobile 1 synth.

However, be forewarned, if you have a oil leak that has been partly plugged by gunk that has built up, it will leak more, but otherwise I dont know of any real downside to switching.

Aaron Z

 

[sixdogs]

Maybe 10 years ago I used Mobil One 15W50 in an old 1973 Ford farm truck and all it did was boost the oil pressure. Ran fine and no leaks or problems. Beats me but it works.

 

[Soundguy]

from what I have seen and heard, no. Aaron Z

And according to amsoil.. you would be wrong.

Not as it applies to the 'new' old machines inthe OP's post.. but in general to the topic of can something be too old.

I emailed amsoil about using syn in a tractor from the 50's.. their answer was that thtere may be some gasket and seal incompatibilities and did not reccomend it unless the engine had been rebuilt in 'modern' times with more modern gaskets and seals.

soundguy

 

[aczlan]

And according to amsoil.. you would be wrong.

Not as it applies to the 'new' old machines inthe OP's post.. but in general to the topic of can something be too old.

I emailed amsoil about using syn in a tractor from the 50's.. their answer was that thtere may be some gasket and seal incompatibilities and did not reccomend it unless the engine had been rebuilt in 'modern' times with more modern gaskets and seals.

I stand corrected. good to know that there is such a thing as "too old" to run synthetic in.

Aaron Z

 

[ampsucker]

i'm with soundguy on this one. my understanding is the synthetic, being all one size at the molecular level as opposed to dino oil which is a bunch of different lengths of carbon chains, can get into spaces the dino oil can't. this is good for lubricity in between metal to metal parts - not so good around rubber seals and paper gaskets that might have just held the seal with dino oil.

i have personal experience with this. my nissan had 160k miles or so and i tried a change with mobil 1. leaked worse than ever around valve cover. went back to castrol regular and it settled back down to the very slow seep it had been doing for years.

there may be additives you could mix in to stabilize any gasket leaks, but why spend the extra money? just stick with what works until you upgrade engines....

amp

 

[czechsonofagun]

I went through the same decision with my 86 CJ7. Synthetic can dissolve some deposit in gaskets cause it to leak, also synthetic can loosen sludge in big chunks and create a problem for the engine.
I used one quart of ATF for 10 miles added to the engine oil to clean it up and than switched to synthetic bland. Nothing bad happened and I eventually went to full synthetic. I use Mobil 1 in both our Jeeps (GC with 4.0 is the other one) and Mobil 1 diesel in my Kubota.

 

[RalphVa]

All three vehicles that I go places in were switched to synthetic with approximately 80k, 135k and 190k miles. No problems at all. I also switched a fairly old Gravely to synthetic. On its 3rd change of synthetic, it finally actually quit using oil. It'll take until about the 3rd change to flush out all the old stuff. It's SOOO convenient to just change once/year. Do that with my tractor, too. Switched it to synthetic at 13 hours.

Ralph