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#30
by
Rabbit on Roids
on 30 Jun, 2009 13:36
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Rotella FTW! just give it the same thing every diesel gets.. rotella is everywhere, and cheap. diesels are way less susceptible to engine wear, compared to a gasser. the gassers inhale the fuel and air at the same time, and the gas washes off alot of the oil on the cylinder wall. as with a diesel, they only inhale air, so when the piston is going up and down, there is more oil on the cylinder wall to help keep wear from happening. thats why it takes most diesels 50-100k miles to get good and broken in.
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#31
by
OM617
on 02 Jul, 2009 01:51
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Beware of Rotella's "synthetic" oil though.
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#32
by
kibs45
on 02 Jul, 2009 23:32
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This is an interesting discussion. MAYBE I can add something maybe not... Oil viscosity is not how "thin" or "thick" an oil is but rather its ability to flow at a given temperature. This may seem like splitting hairs but it actually is an important distinction. Synthetics offer an advantage being a "thicker" oil while maintaining lower viscosity rating. As a side note I use Valvoline Premium Blue. On the additive note, additives do not fix engines, but they can make a situation managable until a complete repair can be made. I would not worry about reuining an engine because you substitute lucas oil for real oil especially if you have a problem you will not be fixing or a while. Just my .02.
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#33
by
clbanman
on 03 Jul, 2009 06:21
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Kib45 makes an important point. 20W50 and 5W50 would give the same protection at high temperatures but the 5W is way better for cold starts (and I don't just mean winter).
As far as the Chevy issue, oil pressure was not a problem on new cars, but when the cams/lifters went (and in the 70's and 80's they went quickly) guys would frequently not replace cam bearings. If you didn't do new cam bearings, your pressure would be way lower than new.
Also, while I have no idea of how true this is for VW's, most North American engines don't require the oil pressure that most people think they do. For example, Smokey Yunick used to recommend 10 psi/1000 rpm for racing engines. Most people would get nervous if they saw 10 psi at an idle. I have heard other reputable sources recommend 15 psi/1000 rpm.
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#34
by
maxfax
on 03 Jul, 2009 14:36
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Too much oil pressure can actually be a bad thing.. Kinda like taking a pressure washer to sand, although it's oil to your bearings.. 10psi per 1000rpm is adequate.. Heck the old GM 60 deg V6's only ever carried about 6 or 7 psi at hot idle...
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#35
by
Zulfiqar
on 03 Jul, 2009 15:13
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for the astronomical oil readings person
I experienced this same problem when we rebuilt a mazda 2.0 gasser engine for a 626.
first start
crank crank - fire - boom (OEM filter explodes to bits)
new Mann filter
crank crank - fire - boom
we were using 10W40 oil and it blew filters
our problem came out to be a stuck relief valve in the oil circuit, causing stupidly high oil pressure
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#36
by
maxfax
on 03 Jul, 2009 15:30
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I had similar problems with my Rabbit, although the relife valve wasn;t stuck.. I suspect maybe it was a bearing clearance issue.... Ended up breaking it in on 5w20 and some rather pricey oil filters...
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#37
by
8v-of-fury
on 03 Jul, 2009 17:11
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I often wonder why all the hype about "synthetics"? I mean they weren't around years back and engines still high mileage with Dino-Oil and no ill effects..?
Why are they so much better really? (this coming from a person with no "oil" experience so don't flame me for it) I mean i understand better lubricating properties and longer oil life (?).. can anyone give a good example why Syn oil is better then Con oil?
Thanks.. im intrigued by this
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#38
by
vanbcguy
on 04 Jul, 2009 11:38
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Well if you think about it:
Dino oil starts with sludge, then tries to take things OUT through refining until it gets a good base stock. At that point the additives come in to make it do what they want. Some of the cheaper brands of dino oil are made from recycled used motor oil too - it's been put through a cyclotron, filtered, probably re-refined and then had the additives replaced.
Synthetic starts from scratch, so there's nothing in it that wasn't supposed to be there. That gives all kinds of ideas to the guys who design this stuff since they can pretty much custom tailor how it will behave.
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#39
by
OM617
on 05 Jul, 2009 05:16
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Why are they so much better really? (this coming from a person with no "oil" experience so don't flame me for it) I mean i understand better lubricating properties and longer oil life (?).. can anyone give a good example why Syn oil is better then Con oil?
Longer oil change intervals, sticks to surfaces better, doesn't break down in viscosity as quickly, blends with (oil company) additives much better, (in diesels) suspends more soot for longer, designed from the start as "engine oil" rather than crude oil refined into "oil for an engine", it lubricates better and you get 1-2mpg better.
Its really better in every way except cost, which is actually cheaper over time due to longer time between changes. People just see the initial cost and think its too expensive. I would spend $107/year (7g oil, 3 filters) on dino, vs $86/year (3g oil, 2 filters) on synthetic for 10,000miles. $21 isn't much, but it will cover two weeks worth of fuel.
Rotella does not make synthetic oil. A legal loophole allows them to sell dino oil cracked to have "synthetic-like properties" as if it were real synthetic. Thats why its not sold in European countries or Canada.
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#40
by
Rabbit TD
on 05 Jul, 2009 11:06
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Another good advantage to synthetic is it's ability to start easier and lubricate better when cold and provide better turbo protection plus the little increase in mileage. I've never tried it in one of these older diesels but I have a feeling it will burn even more than the dino due to the fact it's thinner. But to me the amount these older types burn just just isn't worth it to me and a synthetic will leak quicker than the dino type unless everything is new and perfect and it never is. Is it a better oil, in my opinion yes but worth it in the long run, not to me in these engines. Newer TDI's and such that's a different story altogether.
If it's an older engine definately it's not worth it because most of it will go out the tail pipe or end up wherever you park the car. Another advantage to synthetic though is that it doesn't smoke as much while the engine is burning it. I've known mechanics who worked at car auctions who used to put it in an oil burner so it wasn't as noticable when brought out.
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#41
by
OM617
on 05 Jul, 2009 18:35
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Thats not right. Oil consumption will actually go down when switching to synthetic.
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#42
by
maxfax
on 05 Jul, 2009 19:09
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Oil consumption will actually go down when switching to synthetic.
Actually that's not right.... Maybe in theory it is, but in the real world, rarely....
Generally oil consumption increases when switching to synthetic, especially on an older engine.. Partially due to the molecular structure being smaller, and partically due to it not having all that good sludge in it to plug the oil leaks..
It can also be said that since synthetic does a better job of entrapping particulates it actually helps clean out the sludge already in an engine... The same sludge that has been once again keeping the oil from leaking out gaskets, around valve stems, and to a point past the rings..
Now if an engine is started out on synthetic early enough in life I have noticed that oil consuption remains lower as it get on in miles.. But I woudl believe that is simply to the engine wearing less due to all the properties that make synthetic better...
Early 4.6L SOHC Fords had issues with oil consumption after 100 - 150K miles.. By 200-250K they drank oil something fierce.. When the company I used to work for dumped their 93 Crown Vics for 98's they started them all on Amsoil by 10K.. The one I was driving had a tad over 380K and still never used more than a quart between changes.. Keep in mind changes were done about every 20K...
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#43
by
OM617
on 06 Jul, 2009 01:40
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Actually that's not right.... Maybe in theory it is, but in the real world, rarely....
No theory at all, its reality. The
myth is that oil consumption will go up.
Generally oil consumption increases when switching to synthetic, especially on an older engine.
Only for a short time as the sludge clears out and the oil seals reseat to the new sludgeless position.
My engine used to consume/leak 1qt/1000miles on dino. After a few months on synthetic that has been reduced to 1qt/2500miles.
There is no reason to be scared of switching an old engine to synthetic.
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#44
by
maxfax
on 06 Jul, 2009 02:07
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There are those few engines that will come around and cease to consume oil.. All depends on the condition and composition of the engine...
However if it's already consuming dino oil, it's going to get worse with synthetic, and if the engine is already in that sort of condition, it's not going to get any better.. 90% of the time it'll remain worse...
One of my former VW's consumed approximately 1 quart of dino every 2500 miles.. After switching to Amsoil it consumed a quart every 1000 miles.. It continued this for a year or 60K miles until switching back to dino.. Once back on Rotella it went back to it's normal 1 quart for every 2500 miles..
My 70 Torino is much the same way...With only being driven a few hundred miles a year it's tough to gauge consumption, but with a relatively low milage yet original engine the proof is both on the spark plugs and the floor of the garage.. Now that it too is back on Rotella there are neither drops on the floor nor deposits on the plugs... No myth about that...
My 91 Crown Vic and 96 Grand Marquis are absolutely fine on synthetic.. The the 91 was switched at 150K miles, the MGM at 54K miles.. When I have the new engine done for the VW it too will be on synthetic...
Nothing to be scared of indeed. Some vehicles respond well, others don't.. But as far as cost effectivness if one is already dumping a fair amount of dino oil through an engine it woudl be foolish to be dumping more something that costs more through it...