Ok, here is my question.. For those of you who have used synthetic in your cars/trucks since they were new, does your engine in some cases still develop minor oil leaks or seepage as the engine ages even while using strictly synthetic oil? And if this does happen and all you have ever used is synthetic, and the minor oil leak is too costly to repair, do you continue using synthetic? Does synthetic leak out quicker or not as quick since the engine was maintained on a steady diet of syn oil? Or do you inevitably have to go to a HM product or back to conventional?
? REGARDING SYNTHETIC AND ENGINE SEALS
- Thread starter SFCP
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My two examples -
Used M1 in my Sienna for 75k (about 4 mos ago I blew a seal in the timing belt area - ruined the relatively new timing belt). Can't blame it on M1, just giving the info.
Used Amsoil and M1 in my 88 Mazda - approx. 1994 thru 1998 - finally had to quit due to an oil leak (went to M1 15w50 - no help w/ leak). Went back to reg. dino - leak stopped within one OCI - has never leaked again (not one drop)!
Used M1 in my Sienna for 75k (about 4 mos ago I blew a seal in the timing belt area - ruined the relatively new timing belt). Can't blame it on M1, just giving the info.
Used Amsoil and M1 in my 88 Mazda - approx. 1994 thru 1998 - finally had to quit due to an oil leak (went to M1 15w50 - no help w/ leak). Went back to reg. dino - leak stopped within one OCI - has never leaked again (not one drop)!
Thanks ericthepig,
Folks, this example just given is the one and only reason I'm leary of usng synthetic oil. Because I keep my cars until they are useless to anyone. I drive them until they are ready for the junkyard. Therefore, I wonder if I should just stick to a shorter OCI on conventional?
Folks, this example just given is the one and only reason I'm leary of usng synthetic oil. Because I keep my cars until they are useless to anyone. I drive them until they are ready for the junkyard. Therefore, I wonder if I should just stick to a shorter OCI on conventional?
I've never had one leak on a car running Amsoil. Including one with 270,000 miles.
SFCP, I'm also in the camp of - "if it can be driven to the junk yard, then it's too soon to get rid of it." I'm wanting to get this Sienna out past 250k - getting my wife to drive around w/ kids in a 200k+ van will be the sticky pt. But anyway, I seem to have the same mentality with my oil - I want the best engineered stuff, and then I want to take it out to its engineering limits before dumping it.
(BTW, they may have to get my Mazda in a five or six (or ten) years w/ a tow truck - but I see the Sienna being a fully dependable vehicle out to 300k).
SFCP - before you get paranoid on seals and synths -
My best friend ran a VW van on Amsoil out to around 300k (he put it on Amsoil in '93/'94 and still has the van - though it's recently bit the dust for non-oil related reasons) - he blew one engine seal at around the 250k area - that seems reasonable for an old engine ('85ish van).
He also took a VW Jetta (also '85ish) to around 250k on Amsoil - also started Amsoil in early 90's - no seal problems and essentially zero consumption all the way to ~250k. He sold it around a year or so ago - so that's 15 years of hard Amsoil use (he did TRUE 1 yr OCIs on both vehicles - w/ plenty of miles/yr) - and no oil issues at all (note, the van had a passive filter) - besides that one seal. I'm not putting too much worry time in the Synth. Oil vs. Seals issue (though I still respect the discussion - stays in the back of my head).
My best friend ran a VW van on Amsoil out to around 300k (he put it on Amsoil in '93/'94 and still has the van - though it's recently bit the dust for non-oil related reasons) - he blew one engine seal at around the 250k area - that seems reasonable for an old engine ('85ish van).
He also took a VW Jetta (also '85ish) to around 250k on Amsoil - also started Amsoil in early 90's - no seal problems and essentially zero consumption all the way to ~250k. He sold it around a year or so ago - so that's 15 years of hard Amsoil use (he did TRUE 1 yr OCIs on both vehicles - w/ plenty of miles/yr) - and no oil issues at all (note, the van had a passive filter) - besides that one seal. I'm not putting too much worry time in the Synth. Oil vs. Seals issue (though I still respect the discussion - stays in the back of my head).
i have experienced increased weeping at seals in the initial application of rotella 5w40, followed by none at all within 4k.
it would seem, in my case, that it caused a slight problem and then cured it.
this was witnessed in a kawasaki zl1000 motor and a VW passat v6
it would seem, in my case, that it caused a slight problem and then cured it.
this was witnessed in a kawasaki zl1000 motor and a VW passat v6
As a side note I had a 1985 Toyota SR-5 22REC completely blow the front seal and puke massive quantities of oil all over the place. At around 60-70K miles.
I blame poor seal material.
Conventional quicky lube Pennzoil.
I blame poor seal material.
Conventional quicky lube Pennzoil.
synthetic might find a bad seal, but it certainly won't cause one. If you have a bad seal, replace it.
Synthetics should be able to keep the seal plenty lubricated and pliable since it will resists the formation of varnish and sludge deposits (with logical OCIs). This will keep the seal from drying out and degrading, unlike what the typical saying is for conventional oils that varnish/sludge around the seals and cause them to leak.
i dont get why a synthetic oil would leak any more or less than a conventional oil. its just a fluid.
is it something in the oil which causes the seals to swell or shrink? because thats all i can think of.
is it something in the oil which causes the seals to swell or shrink? because thats all i can think of.
Since 1997, No Leaks from syns. Had a 97 legacy that leaked, but it was the infamous subaru front crank seal that failed on all of them.
That said, I believe this was absolutely true 15 years ago IF you went syn and then went back to dino. I did exactly this in a subaru loyale, 1990, with 30,000 miles on it. Tried syn, no diff in mpg, then went back to dino. Within 2000 miles, every seal on the engine leaked. Front main, left cam, right cam.
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That said, I believe this was absolutely true 15 years ago IF you went syn and then went back to dino. I did exactly this in a subaru loyale, 1990, with 30,000 miles on it. Tried syn, no diff in mpg, then went back to dino. Within 2000 miles, every seal on the engine leaked. Front main, left cam, right cam.
m
bought my tacoma with 52k miles on it (v6 4x4) and put M1 regular syn 5w30 for over 40k miles. i have 93k miles on it now with no problems as far as leaky seals. if you really really want to run syn get the HM syns with the seal conditioner in it like M1 syn high mileage or valvoline syn maxlife..
I had a 2000 VW Jetta VR6. From miles 0-45,000 the car used Castrol Syntec 5w40 with no oil leaks. I switched to Amsoil Euro 5w40 and developed a rear main seal leak within 5,000 miles. Used that oil until about 70,000 and couldn't take the oil leak anymore. Did 2 ARX phases with Castrol GTX and then put in Green GC until I traded in the car at 102,000 miles. It never had a leak after the switching to GC. I will not use Amsoil anymore from my personal experience.
There are at least four reasons that seals leak:
1. Abrasives in the oil
2. Overheat
3. Out of round shaft/bearing/seal location
4. Embrittlement-oxidation
A synthetic oil helps with overheating and embrittlement. Frequent oil changes help with abrasives and embrittlement.
Sometimes manufacturers just blow it and use an inadequate seal to save money.
Seal failures are probably the single biggest cause of a large repair bill in a modern european car.
I have said this a lot of times, but when switching from dino oil to synthetic in an older car, it pays to just add one quart of synthetic the first oil change so that the car "gets used to it". We stopped having problems with cars leaking after we adopted that technique.
1. Abrasives in the oil
2. Overheat
3. Out of round shaft/bearing/seal location
4. Embrittlement-oxidation
A synthetic oil helps with overheating and embrittlement. Frequent oil changes help with abrasives and embrittlement.
Sometimes manufacturers just blow it and use an inadequate seal to save money.
Seal failures are probably the single biggest cause of a large repair bill in a modern european car.
I have said this a lot of times, but when switching from dino oil to synthetic in an older car, it pays to just add one quart of synthetic the first oil change so that the car "gets used to it". We stopped having problems with cars leaking after we adopted that technique.
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