SYNTHETIC SOFTENS SEALS?

[mossad]

I had meant to bring this up in a previous post, but I was told recently by my Dodge dealership tech that using synthetic in my van with 68k and has some slight oil seapage will only help to make the engine seals more pliable and soft. Is there truth to this?
Mostly what I hear is that syn will only cause more leaks, but now I'm hearing that using it will actually help the seals. (???)

 

[KW]

Normally if you have a small leak synthetic will make it worse. On the other hand my Jeep had a small rear main seal leak and after a few hundred miles with synthetic it completely stopped seeping.

How's that for a tap dance...

 

[m2200b]

Did you put syn in the 68k van or is this just
just another round of requests for reasons to support continued use of GTX in this van?

 

[mossad]

quote:

---

Originally posted by m2200b:
Did you put syn in the 68k van or is this just
just another round of requests for reasons to support continued use of GTX in this van?

---

No, I am VERY confident in my choice of Castrol GTX. this is simply regardinng what I've heard about synthetics.

 

[JohnBrowning]

I have never had it happen or seen it happen. I have only heard second hand accounts and 99% of them were from the 1970's. Both oil and seals are drasticly different now! Now only already damaged seals would ever be affected by oil base type.

 

[Tom NJ]

Different types of synthetic base oils have different effects on seals, e.g. PAOs tend to shrink and harden some seals while esters tend to swell and soften. While both effects can, in theory, cause leaks, in reality this is not a "synthetic" issue. It is the responsibility of the formulator to assure his oil is balanced for proper seal compatibility, regardless of what base oils are used.

 

[Ron AKA]

It is interesting how the "old wives tales" vary:

1. Synthetic oil ruins your seals and your engine will leak more oil.
2. Synthetic oil swells your seals and solves oil leaks.
4. Synthetic oil leaks out of your engine faster without affecting the seals.

Is there a slight chance that whether you use syntethic or conventional that neither the oil seals nor the oil leaks are affected in the least? Of course that does not make a very good "old wives tale".

"Did you hear that it doesn't matter whether you use syntetic oil or not that your car is going to leak the same amount of oil." just has no snap to it!

 

[psudaytona]

Well one of my engines front seals has a slight leak(half dollar size area of dripping). I am hoping the Castrol Startup thats now in there does not do anything at all to my seals.

 

[Curious Kid]

If my memory serves me correctly, I had a blend of M1 and GC in the crankcase and after some weeks of driving, I noticed oil seapage beginning on just about every seal. Though I hated to dump it (gave the highest mpg yet...coincidental?), I think I put in a blend of mostly RTS with some M1. After a short while, only the rear main continued to leak, which had developed some months previousely. Since using a blend of mostly C's high mileage with a little Syntec, things have slowed, but I still see a 50+ cent spot.

'95 w/98k miles. I'd imagine with all these blends, it only goes to introduce more variables...creating more problems than it solves in attempting to narrow he result. But I present you with the info none-the-less.