I seriously doubt that revving the engine on a cold startup with 30w oil
would blow the fitler. The oil pump pressure valve would limit the pressure
to 60-80psi or so, no matter how cold or thick the oil is. The filter can
take a lot more pressure than that. I can think of several things that will
blow a filter - faulty installation or the wrong filter can blow out the
gasket. A defective filter could blow, but that is pretty unlikely. My next
vote would be that the oil pump pressure valve stuck shut. I've seen that
happen - it is extremely rare, but on a cold tight engine with heavy oil and
a sticky valve (it's just a ball and a spring, after all), the oil pump can
put out a couple hundred psi or (much) more if the check valve sticks shut.
*That* will blow out the oil filter! Real fast, and quite spectactularly!
And it will make a mess as oil under high pressure sprays all over the
place. And if you don't catch it in time and just keep running the engine,
in a few moments the engine itself will quite nicely sieze.
I don't see what you are trying to say. If you have seen a filter blow,
don't you think it would be more likely to happen if the vehicle also
had the wrong oil, temps were extremely cold, and revving the engine? I
think those three things would surely raise the chance of blowing the
Those three things would only raise the chance of blowing the filter if
something else was wrong in the first place. If nothing else is wrong, those
three things would not mean anything. You can't blow a filter unless the
pressure is too high, and the oil pump keeps the pressure from being too
high, even if the oil is cold and thick and the engine is revved.
You might think so, but a 20Wx oil at -40 in a slant six dodge can
pruduce oil pressures up around the 200psi range on initial startup.
This is because at that temperature the pressure releif (or regulator)
valve can be extremely reluctant to move.
Don't need to rev the engine either
I've blown a filter off a slant 6 myself (20W50 in Winnipeg, of all
the stupid things) and have also seen it happen numerous times with
straight 20W20 oil at -20F - on other brands. On mine it blew off at
Also had the oil pump drive on a Ford 351 twist off in a similar
Exactly! Having the wrong oil means there IS something wrong with the
engine. It has the wrong oil! And it makes the bypass move a little,
or a lot slower and presto, blown oil filter.
Ever try to pull start a little briggs engine with straight 30 weight
oil in the middle of winter. You better believe things move slow.
No, it is working as designed - but the wrong oil is installed. The
film of 30 weight oil surrounding the valve plunger is so
thick/stiff/solid at -40 that it is physically impossible to move it.
SAE20W is bad enough, and straighr SAE20 is even worse.
I suppose there is stuff in solution also, but most of it is particulates in
suspension. And they don't come between metal pieces because there are no
gaps in the engine small enough. Metal on metal contact does not normally
happen in an engine (except for a short period of time following cold
startup, and obviously during a loss of oil pressure, etc.). 99.9% of the
wear that occurs to an engine happens within a short period of time
following cold startup. Anyhow, the rings don't physically touch the
cylinder walls, the rod and main bearings don't touch the journals, the
rocker arms don't physically touch the cam shafts. All of these are
separated by a thin film of oil, and this thin film is thick enough that
most of the stuff in dirty oil fits very nicely inbetween without touching
the metal. That is why you can run an engine with the nastiest looking oil
and not hurt it any.
I've taken apart a lot of engines, and anyone that hwhich is why you can get
a couple hundred thousand miles out of an engine.The oil itself takes up a
certain amount of space, and the stuff that discolors oil is smaller then
My wife and I just bought a 2010 Toyota Matrix. I asked the salesman
about doing an oil change after a few thousand miles. He said that
Toyota uses a break in oil and not to change it. Whatever need be
done will be done during the regular warranty servicing.
Generally speaking, whenever you feel like asking a salesman anything you
are better off to hit yourself in the head with a brick until the feeling
"Break-In Periods" have not been relevant for a few decades now. If it
makes you feel better it's only a matter of 20 to 30 bucks, so go ahead and
Bull shit! Know what you're talking about before you stick you foot
in your mouth. It depends on the vehicle.
Our Constitution needs to be used less as a shield
for the guilty and more as a sword for the victim.
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