Lead in oil
NIck Miller
chance9121 at gmail.com
Mon Sep 6 20:19:13 PDT 2010
Molybdenum is a lubricant similar to graphite in nature, and it also likes
to coat/bond to metals. The addition of molybdenum in lubricants, and
engine oils, is fairly common now, but as to elevated levels in engine oil,
I'm unsure what that would mean, unless the oil itself has more of the
additive, this could be because you add so much oil inbetween change
intervals.
On Mon, Sep 6, 2010 at 3:25 PM, Michael McLaughlin <mcloffs at mac.com> wrote:
> Thanks for the very thorough information. In looking over the report again,
> in both oil analysis reports there's been elevated levels of boron and
> molybdenum. I have no idea what that means. :-) Copper levels were below
> average for both reports.
>
> We typically have pretty cold winters, so I'll look at going with a shorter
> oil-change interval in the winter.
>
> -Mike
>
>
> On Sep 6, 2010, at 7:21 AM, Louis-Alain Richard wrote:
>
> Just to be sure everyone knows about lead in oil.
>>
>> Engine bearings for crankshaft, rods and camshafts are made of a special
>> porous metal called "Babbitt" that contains lead.
>> http://en.wikipedia.org/wiki/Babbitt_(metal)<http://en.wikipedia.org/wiki/Babbitt_%28metal%29>
>>
>> So, this explains why some lead could be found in oil analysis. In normal
>> usage, concentrations should be minimal (a few PPM) as bearings should
>> last
>> hundreds of thousands miles before needing replacement. From what I've
>> seen,
>> I've rebuilt a few engines, the bearings shells are steel-backed with a
>> thin
>> layer of copper over which there is the Babbitt material. So maybe copper
>> in
>> oil would be a more significant telltale for engine bearing wear ?
>>
>> Secundo, in Europe, in fair weather countries, oil changes intervals could
>> reach 30 000km (20 000 miles) and not just for diesel engines. Even the
>> lowly 2.0L ABA engine from the MK3 Golf as such an interval. So you're not
>> extending yours too much if you live where water don't freeze during
>> winter.
>> Cold starts are very hard on oil, more than anything else.
>>
>> Louis-Alain
>>
>>
>> -----Message d'origine-----
>>> la part de Michael McLaughlin
>>>
>>> Thanks for the response. I believe the engine block is indeed iron.
>>> I've been running Mobil 1 5W-40 for the most part, and will look at
>>> chaging the weight. The first oil change I went 10K on synthetic, then
>>> bumped it up to 12.5K at the suggestion of Blackstone.
>>>
>>> The engine uses a bit of oil -- takes a quart or so every 1,500 miles
>>> or so -- so I figure I'm adding so much oil that going with long oil-
>>> change intervals isn't so bad. :-)
>>>
>>> -Mike
>>>
>>> On Sep 5, 2010, at 1:38 PM, NIck Miller wrote:
>>>
>>> Nothing that I can think of... The block in your car is aluminum or
>>>> Iron, do you know? I don't but I assume its iron. Not sure.
>>>>
>>>> If it is in regard to bearing wear, do you run the proper weight oil
>>>> for the engine? perhaps go to a 20w40 and see if the number
>>>> changes, this will offer better protection for the engine/bearings
>>>> because of its increased viscosity, but will hamper the engine ever
>>>> so slightly for the same reason, and it would technically lower the
>>>> power output by a few, at most 2-3hp, in any test I've ever seen.
>>>> So little so that its negligible and within the error range in some
>>>> tests on some dynos...
>>>>
>>>> Anyway, I assume you're intervals for oil changes are around 8-10k
>>>> if you are using analysis, not much I can think of other than do you
>>>> use Cheap 87 octane gas, and maybe bump up the viscosity of the oil
>>>> you use if you think the bearings are wearing too rapidly.
>>>>
>>>
>>
>
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