dirty oil

("Ross" wrote)
Boy, that's a lot of work. I just make sure I change the oil every 3K
miles with new filter and my cars always go better than 200K miles.


75% of the work is deciding to "change the oil today."

Cardboard
Oil pans
Empty gallon milk jugs
Paper towels
Oil changing t-shirt
Go-Jo hand cleaner
Assembling the quarts
Move the other car
Funnel
Wrench

It doesn't add much time running the flush batch through. Everything is
already set up.

Beer
Folding chair
Radio
Left-over pizza


Montblack

Montblack wrote:
Doing our (vehicle) oil changes, I drain the old oil. I use a "flush
filter" that goes on next. I add (less expensive oil) and run the car
for 20 minutes - while I clean up from the first batch.

On my second oil change, the "flush filter" gets drained and returned
to its (labeled) box on the shelf. A fresh filter is used, then I add
my good oil and I'm all set.

I know a few people who like to do a similar thing for old^Wclassic cars
with engines of unknown provenance. If the engine is not showing obvious
signs of distress like low compression, huge oil leaks, lots of end play
on the crankshaft, or poor power (measured by an ANSI standard seat-of-
the-pants test), they do oil changes on short intervals, like 200 or 300
miles, until the oil stops turning black shortly after the oil change.
Once that happens, they go to an interval of somewhere between 1500 to
3000 miles. The oil does get dark by the end of this longer interval.

Many of the engines are old enough to not have oil filters as we know
them, so a "flush filter" isn't used for this process. This is also why
some of the owners prefer a "normal" change interval that is pretty short
by new-car standards. They don't expect this treatment to get them
another 100,000 miles before a rebuild or swap, but they do think it
helps the engine last a little longer than it ordinarily would. This
gives them a bit more time to drive the car and work out the rest of
the problems, and to get the parts together for an engine rebuild.

Matt Roberds

On 5 Mar 2007 12:55:43 -0800, "Denny" wrote:



No one I know breaks the connections and drains the cooler at routine
oil changes...
if the oil is changed before it turns black then the oil cooler will
not have black sludge left in it.. The contained oil will be no
dirtier than what was drained and is diluted by the fresh oil...
Frequent oil changes is the solution...


Lordy,
I don't even have a filter and the oil is black when I change it at 25
hours. However it takes it 15 to 20 hours before the new oil darkens
much.

Now, if you have a pan heater and you are coking your oil with so
called 'preheats' than that residue and char will collect where the
oil flow is the lowest, which is the cooler where the Vernatherm stops
the flow... The cure is to stop using the pan heater...

I use the Tanis which is temperature controlled or rather limited.
It'll peak at somewhat under 50C. Hot enough if you just stick your
hand in there you will jump back, but cool enough that when you expect
it you can put your hand on the pan or cylinder heads and leave it
there.

Dipstick sump heaters are notorious for coking up.


If you recently changed oil types to one that is more aggressively
detergent which acted as a solvent and loosened the gunk in the
cooler, then this is likely a one time issue... A self curing
situation...

Remember the old cars that got a dose of detergent oil after years of
non detergent?


GL .... denny

73

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Thanks for the update, Dan, and glad it is not anything serious. Someone
said that as long as the engine makes full power and doesn't make metal,
don't worry about compressions etc. Presumably that covers black oil too.

Stan


"Dan Luke" wrote in message
...
"Stan Prevost" wrote:

So, Dan, how did this turn out?


Friday, I took the airplane to Teledyne Continental's shop in Fairhope, AL
for a "second opinion" on the engine.

Just got the report: the engine seems fine. Compressions are ok,
crankcase pressure is ok, cylinders all looked good when bore-scoped.

This mechanic said the same thing my regular mechanic said about the dirty
oil: it most likely came from the oil cooler and associated plumbing which
doesn't get drained at oil change unless you pull a line off the cooler.

--
Dan
C-172RG at BFM

I'm sorry; I have to ask: Did you SEE the oil changed?

"Dan Luke" wrote in message

...

"Stan Prevost" wrote:

So, Dan, how did this turn out?

Friday, I took the airplane to Teledyne Continental's shop in Fairhope, AL
for a "second opinion" on the engine.

Just got the report: the engine seems fine. Compressions are ok,
crankcase pressure is ok, cylinders all looked good when bore-scoped.

This mechanic said the same thing my regular mechanic said about the dirty
oil: it most likely came from the oil cooler and associated plumbing which
doesn't get drained at oil change unless you pull a line off the cooler.

--
Dan
C-172RG at BFM

"NVArt" wrote:

I'm sorry; I have to ask: Did you SEE the oil changed?


Changed it myself.

--
Dan
C-172RG at BFM