Check oil when engine is hot or cold?

On 8/8/08 9:52 PM, in article
, "John A. Weeks III"
> wrote:

> In article >,
> Matt > wrote:
>
>> wrote:
>>> On my 15 year old Accord, I get different dipstick readings when the
>>> engine has been sitting overnight vs. checking 10 minutes or so after
>>> the engine was running for a while.
>>> Most probably due to settling of oil into the pan over long time
>>> periods.
>>> When is it best to check oil. In the morning after the engine sits
>>> overnight, or after being driven for a while?
>>
>>
>> RTFM :-)
>
> What does the "FM" say these days? When I learned how to drive,
> the procedure was to:
>
> 1) start the engine when it is cold
> 2) let it run for 1 minute
> 3) shut it off
> 4) check the oil 1 minute after you shut it off
>
> Is that still the current ideal procedure?
>

Never heard that one before & I've been driving for 43 years. Where did you
hear this procedure? It really is non-repeatable engine to engine, varies
with temperature, etc. Lots of reasons this is not an ideal procedure.


> In reality, as long as you are not too high and not too low, you
> are probably OK, so it likely doesn't matter too much how you
> check it.
>
> -john-

"Tegger" > wrote in message

> The comparative validity of any measurements lie in the consistency of
> method from instance to instance.

> Tegger

Good point. I think you should check it after it is completely drained down
too.
You want to know that it is above the minimum level, and ***not too far
above the
maximum***. And you can only know that for sure when it is completely
drained
into the pan.

"HLS" > wrote in
:

>
> "Tegger" > wrote in message
>
>> The comparative validity of any measurements lie in the consistency
>> of method from instance to instance.
>
>> Tegger
>
> Good point. I think you should check it after it is completely
> drained down too.
> You want to know that it is above the minimum level, and ***not too
> far above the
> maximum***. And you can only know that for sure when it is completely
> drained
> into the pan.
>



And, I have found, that only happens completely if the engine sits
undisturbed overnight.

I've spent the last seven months (covering some 8,400 miles) doing
extremely precise measurements of my oil consumption. Each and every
check (seven recorded checks so far, many more unrecorded) has been done
in exactly the same manner. Precision is critical for anything like
this.

Now, I am confounded by one imprecise factor, and that is the actual
stick reading, which is done visually against a millimeter-graduated
scale I devised for the purpose. I have found that, not only does oil
take all night to fully drip down into the pan, but the stick reading is
different from front to rear on the stick. In addition, each time you
pull the stick to check and put it back, the next reading may vary by as
much as 1/2 a millimeter from the previous one unless you wait five
minutes or so between stick pulls. In addition to all that, the level
indicated on the stick may not be a flat line, but may be concave or
convex, this apparently random, but surely tied to something I haven't
discovered yet. All this means it is difficult to pin oil level to an
exact reading, or consumption down to anything finer than 50 or 100 mile
increments.

These are my readings. Odometer is in kilometers, all else is US
Imperial:
Jan 23/08 - 477,832 to 479,441 - 2,500 mi/qt - avg temp about 10 - 1st
thousand on oil
Feb 20/08 - 479,624 to 481,233 - 2,175 mi/qt - avg temp about 10 - 2nd
thousand on oil
Mar 28/08 - 481,975 to 483,551 - 2,500 mi/qt - avg temp about 30 - 1st
thousand on oil
Apr 17/08 - 483,583 to 485,268 - 2,350 mi/qt - avg temp about 40 - 2nd
thousand on oil
May 11/08 - 485,721 to 487,373 - 1,650 mi/qt - avg temp about 50 - 3rd
thousand on oil
Jun 14/08 - 487,963 to 489,663 - 2,150 mi/qt - avg temp about 65 - 1st
thousand on oil
Jul 03/08 - 489,699 to 491,418 - 1,800 mi/qt - avg temp about 75 - 2nd
thousand on oil

This gives me an average consumption of about 2,100 miles per quart.
Oil age seems to be a factor in consumption, as does ambient
temperature. In a year or so I should have enough data to determine more
convincingly the most important factors governing my oil consumption.


--
Tegger

On Sat, 9 Aug 2008 23:40:41 +0000 (UTC), Tegger >
wrote:


>
>This gives me an average consumption of about 2,100 miles per quart.
>Oil age seems to be a factor in consumption, as does ambient
>temperature. In a year or so I should have enough data to determine more
>convincingly the most important factors governing my oil consumption.

You are trying to be too precise. Many things can affect oil
consumption, especially on a worn engine. Acceleration, traffic
conditions, driving practices in general, temps, etc, etc.
Here's something to ponder.
I rebuilt a 352, jobbing only the case bath, cam bearing insertion and
the heads.
Ran perfect, but was using a quart of oil every 500 miles or
so with the mostly city driving I was doing. I suspected the valve
guides, since I had jobbed the heads.
This was confirmed when I took a trip to Yellowstone, driving about
4000 miles total, and used no more than 1/2 quart of oil for the trip.
Back home in the city, pulling vacuum when backing off for
lights and stop signs started sucking the oil through the guides at
the same quart per 500 miles.

--Vic

In article >,
E Meyer > wrote:

> > What does the "FM" say these days? When I learned how to drive,
> > the procedure was to:
> >
> > 1) start the engine when it is cold
> > 2) let it run for 1 minute
> > 3) shut it off
> > 4) check the oil 1 minute after you shut it off
> >
> > Is that still the current ideal procedure?
> >
>
> Never heard that one before & I've been driving for 43 years. Where did you
> hear this procedure? It really is non-repeatable engine to engine, varies
> with temperature, etc. Lots of reasons this is not an ideal procedure.

My father was a master mechanic and instructor at a major Army
base near Washington DC in the 1950s, and, as you know, the Army
has a process and procedure for everything. For oil, this was
they way you did it.

-john-

--
================================================== ====================
John A. Weeks III 612-720-2854
Newave Communications http://www.johnweeks.com
================================================== ====================

On 8/11/08 9:49 AM, in article
, "John A. Weeks III"
> wrote:

> In article >,
> E Meyer > wrote:
>
>>> What does the "FM" say these days? When I learned how to drive,
>>> the procedure was to:
>>>
>>> 1) start the engine when it is cold
>>> 2) let it run for 1 minute
>>> 3) shut it off
>>> 4) check the oil 1 minute after you shut it off
>>>
>>> Is that still the current ideal procedure?
>>>
>>
>> Never heard that one before & I've been driving for 43 years. Where did you
>> hear this procedure? It really is non-repeatable engine to engine, varies
>> with temperature, etc. Lots of reasons this is not an ideal procedure.
>
> My father was a master mechanic and instructor at a major Army
> base near Washington DC in the 1950s, and, as you know, the Army
> has a process and procedure for everything. For oil, this was
> they way you did it.
>
> -john-

OK. It makes more sense in that context. I was in the Army in the 70's.
Saw lots of weird stuff in those manuals.

E Meyer wrote:
>
> On 8/11/08 9:49 AM, in article
> , "John A. Weeks III"
> > wrote:
>
> > In article >,
> > E Meyer > wrote:
> >
> >>> What does the "FM" say these days? When I learned how to drive,
> >>> the procedure was to:
> >>>
> >>> 1) start the engine when it is cold
> >>> 2) let it run for 1 minute
> >>> 3) shut it off
> >>> 4) check the oil 1 minute after you shut it off
> >>>
> >>> Is that still the current ideal procedure?
> >>>
> >>
> >> Never heard that one before & I've been driving for 43 years. Where did you
> >> hear this procedure? It really is non-repeatable engine to engine, varies
> >> with temperature, etc. Lots of reasons this is not an ideal procedure.
> >
> > My father was a master mechanic and instructor at a major Army
> > base near Washington DC in the 1950s, and, as you know, the Army
> > has a process and procedure for everything. For oil, this was
> > they way you did it.
> >
> > -john-
>
> OK. It makes more sense in that context. I was in the Army in the 70's.
> Saw lots of weird stuff in those manuals.

It is not a completely dumb procedure. With the engine running you
don't want too much oil because the crank will whip it like an egg
beater and you don't want too little or the pump will suck air. So a
test that takes into account how fast it can get back to the pan does
make some sense.

-jim


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John A. Weeks III wrote:
> In article >,
> Matt > wrote:
>
>> wrote:
>>> On my 15 year old Accord, I get different dipstick readings when the
>>> engine has been sitting overnight vs. checking 10 minutes or so after
>>> the engine was running for a while.
>>> Most probably due to settling of oil into the pan over long time
>>> periods.
>>> When is it best to check oil. In the morning after the engine sits
>>> overnight, or after being driven for a while?
>>
>> RTFM :-)
>
> What does the "FM" say these days? When I learned how to drive,
> the procedure was to:
>
> 1) start the engine when it is cold
> 2) let it run for 1 minute
> 3) shut it off
> 4) check the oil 1 minute after you shut it off
>
> Is that still the current ideal procedure?
>
> In reality, as long as you are not too high and not too low, you
> are probably OK, so it likely doesn't matter too much how you
> check it.
>
> -john-
>


Warm engine, level ground, a few minutes after turning it off (e.g.
after fueling).

If you want to know your burn rate, you want a /consistent/ and
/convenient/ method. If you are driving across the country, you can't
wait for the engine to cool each time you check the oil, so you do it
when the engine is warm.

Get it?