I don't have anything about buying oil at Walmart. There was some undeniable irony about grm386wa being critical about the member that started this thread. Take a look at his posting today under the theme of Sneaky Pete in the Product Rebate section of this site. You will understand my reference to WalMart.
A DISCUSSION WITH MY MECHANIC
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Other properties of the oil such as cohesion or adhesion, and maybe to a lesser extent seal swell or shrinkage.
mossad, you said you have seepage, correct? Well if it is truly seepage and not a leak, I doubt if you will see any difference. I think most manufacturers consider a leak to be a drip or some flow of oil, while seepage is moisture around a gasket/component joining area. If you have a leak, synthetic oil may make it worse. If it is seepage, then you really shouldn't be losing any measurable amount of oil either way.
If that is the case do you not lie awake at night worrying about your synthetic oil flowing off all the parts in the engine, leaving them exposed to severe wear on the next start?
No. When I was a engineering student, and young and stupid I might add, I ran a home experiment with the original Mobil 1 5w20. I didn't see any increase in wear whatsoever. Convinced me that they had a clue. Never looked back.
If I had a "mechanic" that voiced something that stupid I'd sure not ask him for more oil advice. I hope he knows more about car engines than he does about motor oil.
A couple reasons. Similar to to what 427Z said. And at the molecular level the more uniform nature of PAO and POE vs. the varied chains of petroleum oils tend to flow faster/better through small spaces. Also, IMHO, older conventional oils tended to be more self sealing - the conventional oils and their more VII's tended to "crust" up at a leaking gasket or seal. Maybe slowing the weep. Along some a synthetic oil and it dissolves this crust and the leak increases.
My 78 Monza had a 'seeping' rear main seal..there was crusty, dirty dried oil around the area, but never a drip on the driveway until I put synthetic in. Like Pablo said, it flows better through small holes than conventional oil, and while it's doing so it's dissolving the crud that may have been keeping the holes small.
seep, weep =leak (just the volume escaping is lower
)
The way I look at it, either a closed oil system leaks or it doesn't. It's a binary discussion.
The way I look at it, either a closed oil system leaks or it doesn't. It's a binary discussion.
This is silly. Yes, synthetics will likely dissolve the crud and expose a leak. In this case fix the leak. I have been down this road before and the old seals needed replacing anyway. With worn main bearings, the crank can move around enough that even a new rear main seal will be tested. Use a thicker viscosity, or fix the problem with a rebuild.
If you don't want to fix any leaks, then use an oil with less solvency.
On the going to 15K miles with Mobil 1, this is only possible if you have excellent air filtration and a very well tuned engine. Otherwise you need to stick to "normal" change intervals to get the pollutants out of the oil.
If you don't want to fix any leaks, then use an oil with less solvency.
On the going to 15K miles with Mobil 1, this is only possible if you have excellent air filtration and a very well tuned engine. Otherwise you need to stick to "normal" change intervals to get the pollutants out of the oil.
Pablo, its not that simple. I've seen dry/old seepage that never turned into a leak. The only reason to fix something like that is for peace of mind or to enrich the repair shop. A true leak should probably be repaired but there's no reason (except as noted above) to fix seepage.
And if your synthetic oil contains Olestra...oops...different kind of leakage, nevermind.
So what is seepage? Imaginary oil creeping out? Only the "light" fraction of the oil coming out? Is a leak only a leak if you see drops?
It doesn't surprise me that a car that has seepage and the owner thinks/says "no leaks", then switches to synthetic and says "look, no leaks before, now with syn it leaks!"
Seepage is just a very, very slow leak. "Most" will engines have seepage? Interesting.
It doesn't surprise me that a car that has seepage and the owner thinks/says "no leaks", then switches to synthetic and says "look, no leaks before, now with syn it leaks!"
Seepage is just a very, very slow leak. "Most" will engines have seepage? Interesting.
my bimmer is on 174,000 KM's (approx. 108,000 miles)
i switched over to synthetic at about 171,000 KM's. at the time, i was very hesitant to do so. i didn't know much about oil and the differences between different oils at all. i asked so many people if they think i should change to synthetic, and all i got was mixed answers. so it basically came down to a personal choice. so i said, lets just try it and see! and everything is OK! the car doesn't leak or burn any oil.
i switched over to synthetic at about 171,000 KM's. at the time, i was very hesitant to do so. i didn't know much about oil and the differences between different oils at all. i asked so many people if they think i should change to synthetic, and all i got was mixed answers. so it basically came down to a personal choice. so i said, lets just try it and see! and everything is OK! the car doesn't leak or burn any oil.
Mossad,
Your mechanic has not been trained in lubrication and evidently isn't interested in learning anything.
Whether or not he was impressed in the color of the oil is meaningless. The only way to know if the oil is exhausted or still good is to have a lab run a ~$20 oil analysis.
3000 mile oil drain intervals are a waste of time, money, and precious oil. Good profits for the oil change shop and oil and filter companies, tho.
Ken
Your mechanic has not been trained in lubrication and evidently isn't interested in learning anything.
Whether or not he was impressed in the color of the oil is meaningless. The only way to know if the oil is exhausted or still good is to have a lab run a ~$20 oil analysis.
3000 mile oil drain intervals are a waste of time, money, and precious oil. Good profits for the oil change shop and oil and filter companies, tho.
Ken
Our civilian terminology/thinking was that the long synthetic molecules would keep going once initiated into a seal/gasket.
Pablo, I have some manufacturer's bulletins at work that state the "official" meaning (according to them) of seepage. I'll try to paraphrase: seepage is a light/thin film of fluid around gasket sealing surfaces that is not wet to the touch; the seepage may represent current moisture or be evidence that there was a film of fluid in past and is now dry and/or shows an accumulation of dirt. All manufacturers that I know of do not recommend the replacement of the gasket to correct this occurence. Most, if not all, of them will not cover gasket replacement due to seepage under warranty. A leak, OTOH, is a visible drip or pooling of fluid beyond the gasket or excessive moisture buildup around a sealing area that is moist to the touch and will leave fluid or fluid residue on your finger. I've seen many, many examples of both and can tell instantly between the two. There are at least two reasons that they will not recommend replacement of the gasket for seepage 1) The new gasket will likely have some seepage sooner or later, and 2) The seepage is not affecting anything i.e. the loss of fluid is almost zero. Probably one reason is also the cost to repair something that is not really causing any problems.
Some gaskets progress from seepage to leakage as they "get worse" and some seep a little for years and never start to leak.
Some gaskets progress from seepage to leakage as they "get worse" and some seep a little for years and never start to leak.
Thanks cfromc. I was being a bit logically facetious
I guess my main point as stated earlier - some folks are surprised their cars leak oil on synthetic when the say they "didn't have any leaks before". When that truly is not the case.
Pretty good and along my thought lines. I have seen exactly what you describe many times. I will agree if the seepage has stopped, then you maybe don't have a current leak. I'll also agree that it's not worth going in and replacing the gasket/seal. However, I maintain that if you really clean the area spotless and then within some time period (week?, month?) the seepage is back, then you have a leak regardless if it forms a drop.
I guess my main point as stated earlier - some folks are surprised their cars leak oil on synthetic when the say they "didn't have any leaks before". When that truly is not the case.
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