Best way to change oil

[bobs409]

Here's something I've been thinking about lately...

Is it best to run engine until hot, then change oil or wait until the engine has set for many hours or days, then change it?

It seems to me, you would get more of the dirty oil out if you changed it while cold. (and let it drain it for a whole day too)


Thoughts???

 

[tripowerguy]

I never did it that way, I've always warmed up engine thinking that it would pickup all the contaminates and flush them out. I always let it drain until no more oil drips from pan. When I went to high school I worked in a gas station, you know the kind where you washed the windows and checked the oil. Anyway Sat. was the big oil change day, people left their cars for an oil change and lube job. Some times it was hours before we got to some of them. We didn't warm them up just pulled them in on the rack and dropped the oil. Roy

 

[dq409]

I prefer to run the engine till hot,,,,let cool a while then drain. My thoughts are it will drain (flush) all the oil and contaminates to the pan then will flush out with the oil. If it`s cold oil the contaminates will settle to the bottom of the pan and not flush with the heated oil. IMO,,,dq

 

[fourspeed409]

I change my oil every 500 miles or every bearing change. Which ever comes first.:

 

[bowtieollie]

You want to run that engine until it reaches operating temperature.

Note - if the coolant is at normal operating temperature - it takes quite a bit longer for the oil to reach normal temperature.

Then change the oil.

Changing cold oil - doesn't remove the impurities totally - which you are trying to remove when changing the oil.

When the oil is warm, its less viscous - so it runs out easier. Also, the impurites are suspended in the oil when warm.

Now, go take care of the engine, BOB!

 

[bobs409]

Oh, im taking care of them. They are my babies!

The reason I even mentioned this is that if you run an engine prior to changing the oil, then all the oil that has ciruculated to the top of the engine won't come out. Unless you just leave it drain for a long time.

On the other hand, a cold engine will have all oil collected into the oil pan already from your friend and mine, "gravity."

Maybe the best way is to get it hot, and let it drain for a day.

Just one of those things that crossed my mind...

 

[CDNpontiac409guy]

Bob... As Ollie said.... and yes, I DO !... I generally let the oil drain at least 4 hours... usually over night. After a half hour or so, I also will raise the rear of the car and put it on stands... allowing for as much as another 1/2 litre ( quart ) to get out.
When I do it this way, I usually end up putting a total of nearly 6 1/2 litres of new oil in ( ALWAYS completely filling the filter first ).
This quantity applies to the 409 pan.

No point in changing oil if you didn't get the old stuff out !

I change mine every 1500-2500, depending on the engine. The high compression/high load applications take more of a beating. The best straight grade 30W I can find for the summer, and 10W30 for the cooler months.

Been talked into using Synthetic after break-in for my "Stocker" engine:eek: !

 

[kbc409nova]

Aubrey
What brand of oil do you prefer to use?
Kevin

 

[SS425HP]

Oil

Good question to get started. Why the brand you use? And, synthetic versus regular oils.

Fred

 

[CDNpontiac409guy]

HHHMM... funny you would ask....
For nearly 20 years I used Quaker State. I'm now using Imperial oil products ( Esso ). good Alberta based crude

 

[IgnitionMan]

OK, lets use some common sense here.

Starting an engine to get the oil hotter to change is not too bright an idea. Why take the oil that has drained down from the hot engine cooling down back through the engine all over again, then have to wait to get the stuff to redrain. Not a lot of common sense there.

The common sense thing to do is, get everything ready for a change on a prescribed schedule, then, when the vehicle is stopped for the night, drain the oil out, overnight, and change the filter the next morning, put the drain plug back in and oil it up. Some do something like that here now.

It makes no sense at all to stop the engine for an hour or two, or 4, then restart it to get the oil hot again, moving all the dirty stuff that has already drained into the pan and put it back into the top end, valley, etc.

In testing at both GM and Kawasaki when I worked at both, we consistantly found that cold changes/long drain times got more contaminants out of the engine than firing the engine up and putting what had already drained into the pan, back into the rest of the engine just to get the oil to drain a little faster. Average drain times to get the most oil out of the engine ran between 7 and 8 hours, consistant from the auto to bike engines. Cold draining got more oil and contaminants out of the engines, as there was more oil in the pan to drain, than the oil that was still captured in the uppeer end of the engine from "thinning it out" from heating it back up. We tested the two methods by doing the drain, then pulling the pans off the engines and physically looking at what was left in them, so no speculation on this.

We also found that drainback to pan times for the oil took a consistant time of between 6 and 7 hours, no matter the engine design or type.

 

[bowtieollie]

I think this topic has been hashed out to the ninth degree - but here's the short story....

API classification SL will offer the best protection and least friction.
Granted there are many brands of oil that meet this classification, but some are better then others.

Pennzoil, Shell Rotella, and Mobil One are the three best.
The Mobil is a synthetic and is priced accordingly.

Don't waste your money on the syn blends.

If you are driving high miles and wish to have extended change intervals - then the Mobil One is the way to go.

If you are an enthusiast and only drive the vehicle occasionally, then the Pennzoil or Rotella are the choice.

10-30 is the best viscosity for protection and reduced engine "internal" friction. If you are dealing with temps below 40 degrees - then use the 0-30.

If you have a worn engine, the 20-50 or 15-40 would better choices to deal with the loose bearings. Straight weights are not recommended due to their poor cold start flow rates.

May as well address the oil filter topic too - AC Duraguard for everyday use. If you are going to run the Mobil One - then AC Ultraguard or Mobil One filter.

All the other filters are LESS THAN CAN BE DESIRED in filter media, construction, and protection abillity. FRAM IS THE WORST.

The AC Ultraguard is manufactured by the same company building the Mobil One filter.

Many of you may say - what gives me the right to post this info? Well, years of research with the company I work for is the best answer - followed by years of experience in the auto industry and the results during tests and field studies.

Now all the engines on this site should be happy, make more horsepower, and live long.

 

[bobs409]

Thanks Ignitionman. This is one of those things that just crossed my mind while out cruising one day.

From now on, im going to drain over night.

As for the oil debate...im still undecided. I've been using Pennzoil for eons with no trouble but it seems that everyone on this board (except Ollie) warns me against it. None of my engines ever suffered from using it. So...do I go with majority rule or what I've seen with my own eyes? Im still undecided on that. Then there is the question of what to use if I switch from Pennzoil.

At least oil filters are certain. I always us AC's and always will. Same with spark plugs.

Let the debate begin.

 

[bowtieollie]

Originally posted by bobs409
I've been using Pennzoil for eons with no trouble but it seems that everyone on this board (except Ollie) warns me against it. None of my engines ever suffered from using it. So...do I go with majority rule or what I've seen with my own eyes? Im still undecided on that. Then there is the question of what to use if I switch from Pennzoil.

Glad to hear this Bob!

Now, I wonder why "everyone warns against it"??????
No doubt another wives tale floating around out there with no scientific results to support it....

 

[IgnitionMan]

bowtie, I agree with you, well done on the posts. You hit a bunch of stuff dead on right, as usual.

Nowever, I disagree with you on the Pennzoil, only because after looking down into a just emptied bottle eons ago, seeing small particles in the oil, and having them analized, I just won't run Pennzoil. Analysis showed the particles to be grit, not any additive package component, but iron grit, very fine micron size, but still visible. This was from a clean, just drained bottle, and after that had 5 more samples from other bottles analized, same-same.

But if you guys like it, hey, use it. like Valovline, Castrol natural oils, not the racing for street use, straight weights, not multi-viscosity, so that just works for me.

 

[bowtieollie]

Hi IMan,

Glad to see you are around!

That is a really strange story about the oil contamination.

With mass production, anything is possible - afterall, how many people stare into the oil bottle?

Reminds me of the Quaker State story years ago with noisy lifters. They forgot to add the detergent to the oil. It took them a very long time to get over that one -since it did make it to the media.

The scientific studies we did on all the different brand non syn oils available for gasoline engine use - showed that the Pennzoil had the best ability to "last the longest".

The way we treat these cars/engines - we baby them to death. So I really don't think the "brand" of oil is so important - as long as the API classification is SL.

I know from the engines in my fleet - the oil comes out as clear as the day it was poured in.

 

[IgnitionMan]

bowtie, good people here, you'll like 'em. And, you are needed here.

All I know is, I was very surprized at the iron particles in the Pennz, those many years ago, but when somebody I see is putting Pennz into an engine now, like outside a Pep Boys or Auto-Zoned-Out, I ask for the empties, take a look, same partilces from years ago in these new bottles.

 

[bobs409]

Igntionman,

Just for the heck of it, have you ever tried to contact Pennzoil to see what they say about these particles? I checked a few bottles including a 5 qt jug and at first, there were no particles but then....I did find 2 qts that had it! :eek:

Have you ever seen this on any other brands? Some brands like Havoline use a black container so no way to see it in that one.

I'd love to see what Pennzoil has to say about this.

 

[IgnitionMan]

Both Kawasaki R&D and I asked Pennzoil what the particulate matter was, after we had the reports, never did get an answer, not just a strange or phony answer, but no answer at all.

For black bottles, cut the bottle open and scoop the oil out of the bottom with a clean paper towel. That should catch any residue on the towel for inspection.

Shell RPM Delo, Havoline seem to be good stuff.

I changed from multi-vis to straight weight oils in all of my motorcycles and cars, and got better oil pressures and the oils stayed cleaner between changes, engines ran silghtly cooler doing same. Of course, I live in the west so the climate is more tolerant of higher viscosities, but I have friends whom have done the same thing back east with lighter straight weight viscosities, and have had similar results.

One thing we have to remember is, the engines we are playing with have parts with metallurgies that weren't ever designed for use with, or compositions/hardnesses to use the lighter oils, and specifically, synthetics. Now, a new Corvette or Mustang engine has different hardening treatments on things like light induction hardened crankshaft journals, cams are roller to reduce frictional drag (which takes heat away from the oils from the lowering of that friction), updarted bearing materials that can operate just dandy with 0WNothing viscosities, so these newer engines can attain maximum mileages. Not much like earlier pig iron parts that really like old dead rotted dinosaur goo.

I know one day soon, I will go to an auto parts store and see the latest in oil viscosities, the -00w-000 lighter than water "oils", the ultimate in non-lubrication, for your super understressed economy throw-away disposable new vehicle.