synthetic oil bad??

[KORNBREAD]

Heard a guy this evening at the parts store say that older motors cant handle full synthetic motor oil. That the seals cant stand up to all the detergents and you will start having leaks with in a few months. Also said that the older motors are prone to spun bearings because of how slick the oil is. I have never heard this and now has my attention. I googled it but no matter where I look its a 50-50 on yes and no. Anyone know for a fact??

[mudbillyredneck]

I know for a fact .

That I have been running full syn in all my junk for over 10 years ( rangeing from 1986 to 2004 ) ....no leaks ....no spun bearing's ......I run Fords though ...so who know's  

[BIG DOG]

mudbilly your a head   lol       .i never heard nothing bad about it    ford  or CHEVYS  lol

[mudboggincrazy]

i use 2 run it in all my trucks made a huge diff in oil psi and how the motor ran but i got sick of the oil leaks after about 2-3 mths  and that was in  brand new motors and well used motors that never leaked oil before switchin but im a chevy guy maybe they use cheaper seals then ford lol

[BUDGETBOGGER03]

I use 10w30 normal oil in my jeep and always have 60-80 press knock on wood

[ToughBowtieTruck]

First, define "parts store"

That could have a lot of meaning depending on where . . .

[KORNBREAD]

No it was a random guy I was talking to IN the parts store. I dont ever talk mechanics with "parts stores" employees.

[OHEARN.2012]

i could see it happening because motors back then were used to the old brand of oil but who knows

[ToughBowtieTruck]

No it was a random guy I was talking to IN the parts store. I dont ever talk mechanics with "parts stores" employees.

Ahh.

Well he's speaking general crap. It all depends on how an engine was taken care of, thus, how well the gaskets and seals in the engine are conditioned.

Old engines typically have seals that can dry out faster, so if the engine was neglected, switching could cause it to leak due to the different properties of synthetic (NOT supposed to break-in new engines on it either, but more and more cars and trucks are coming with synthetic from the factory now). But on the other hand, if the seals are going to be adversely affected by synthetic to begin with, then it has its own issues IMO.

And, think about this: All trans fluid is, is detergent! Old transmissions that were taken care of don't leak! But if they were neglected, oh boy.

[Andy Michalik]

The base stock of a sythetic is better if look under a microscope the molecules are all the same size roughly standard oil isnt. So it flows and protects better. With that being said if you have a seal that is going bad thats why they tend to leak more no big out of size molecules. On that note i would advise running it in almost anymotor. And unless its methanol it wont make you spin bearings loss of oil pressure does that. If thats a common problem switch to a teflon coat mahle. Clevite bearing.

[Jthomas]

loss of oil pressure does that. If thats a common problem switch to a teflon coat mahle. Clevite bearing.

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