in oil, but not many. Break in oil was mostly used by shops after
rebuilding an engine. On a rebuilt engine, things were mighty tight
as a rule, what with new inserts and rings. Break in oil was
usually drained and replace with regular oil at 250 miles. The
theory was that the lighter oil helped parts seat in. Any metal
shavings, burrs, etc would be drained at 250 miles along with the
oil. Seemed to work then, but now days, I don't think it is used at
It's up to you.
Last new vehicle I bought (still have it) is a 2000 Chevy 3500 Express
Van. No early oil change was specified but it did say to go easy on it
until so many miles. I'm one who sometimes can't leave good enough
alone, so I changed the oil at close to 1000 miles. Two surprises at
once. First was a magnetic drain plug like they used to sell only at
places like "JC Witney". Second surprise was all the metal filings
stuck to the magnet! There was a lot, well in my eyes it was a lot. It
was enough that I changed the oil again after 2000 miles (and that put
me back on the 3K mile intervals). The second oil change had much less
metal stuck to the magnet. After that there has always been much much
less on the magnet, just a little "fuzz".
My biggest surprise was the good old magnetic drain plug. I had never
seen one in actual use before and this one came from the factory. JC
whitney was 20 years ahead of their time.
I also go with the 3K mile oil change. Many say it's a waste, but what
the hell, in the 70,000 miles I have on that van, oil changes have only
cost me about $500. An estimated $700 every 100,000 miles? That I can
afford for peace of mind. If I can afford about $14,000. in
gasoline/100000 miles, the oil changes are a drop in the bucket.
So why not drop that $350 difference in my bucket? I've not changed oil
at 3000 miles in the past 25 years and I've never had an oil related problem
in cars that I've put up to 200,000 miles on. Why waste money on oil
changes when you can buy a case of beer instead?
Your money, do as you please, but mine will be put to better use.
The particles that you see in the oil that cause it to look "dirty" are too
small to hurt anything. They remain in suspension and never come between
metal pieces, and therefore don't cause wear. The oil filter will remove
anything big enough to cause any damage.
I used to work at a gas station, and I remember once this old famer coming
in. We checked his oil, he took a look at the dip stick, rubbed it between
his fingers, and goes "yep, feels gritty, must be time for an oil change".
By then I had learned to just keep my mouth shut, smile and change the oil.
There was no way we could ever convince him that "gritty" oil would destroy
the engine in about five minutes flat. He was happy, and his oil got changed
when it needed to ...
Some industrial equipment have pressure guages across the oil filter, and
they don't change the oil filter until it's plugged enough that a certain
amount of pressure develops across it. The reasoning is that a filter
partilly plugged filters finer particles then a brand new one. They won't
change the filter until right before it starts to bypass. I don't think they
do that today - easier to just replace it regularly rather then watch the
pressure guage and catch it shortly before it bypasses.
Yah - the filters only bypass when the filter element is sufficiently
plugged. Oil pumps have a pressure regulator that bleeds oil back into the
crankcase if the max pressure is exceeded. This happens at cold startup and
FWIW - one of my old instructors built race car engines, and he told us of
the time he put a high volume oil pump into one of his engines. Took it out
on the track and the engine siezed before he completed one lap. Come to find
out that the drain holes in the head were not big enough to drain the oil
into the pan as fast as it was getting pumped to the rocker arms. The top of
the engine filled up with the oil, oil pan went empty, and bye bye engine.
Maybe. The last old car I had used a cartridge filter (i.e. the cartridge
was replacable, but the housing was retained - unlike modern filters
where the whole filter can is swapped). The cartridge was held in
place under spring tension by what was essentially a valve - too much
pressure (or a blocked filter) and the valve would open.
Whether any modern "all in one" filters have a built-in mechanism
like that though, I don't know.
Do you remember the toilet paper oil filter cartridge kits?
It was a reusable filter replacement for the spin on throw
away filters. I saw ads for them but never got my hands on
one of them. Some toilet tissues I've come across remind me
of oil filter media material. OUCH!
MOST filters have a bypass on them, but they are set to bypass when
the pressure difference across the filter gets too high (blocked
filter) GENERALLY they do not come into play from cold, and virtually
never because of high engine speed (which increases oil flow - and
therefore pressure across the engine clearances, but not the filter.)
All oil filters restrict oil flow. Some more and some less. If they
didn't, they couldn't filter. Cold oil is less fluid and causes the
pressure difference to increase. Revving the engine pumps oil faster.
Wherever there is a restriction the greater the pressure difference.
One very cold day I saw a guy at work start his car. He always revved
it up when it started, and he only used 30 weight oil. That cold day
the oil filter blew out from all the pressure and he had quite a mess to
clean up and a filter to replace. I suppose the bypass or regulator in
the motor was a little too little, or a little to slow opening up.
Which is why any modern vehicle will specify multi-grade oil. There the
viscosity is modified by the additives to _not_ increase drastically w/
The failure you state was an extreme aberration at best; I'd think it
more than likely it was a case of either wrong oil or cheap filter or
combination of both and perhaps other causes as well...
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