Changing oil advice? Running engine for 5 seconds to drain extra oil?

Reply

  #1  
Old 07-05-11, 10:48 AM
Member
Thread Starter
Join Date: Jun 2003
Location: Canada
Posts: 164
Changing oil advice? Running engine for 5 seconds to drain extra oil?

Just a quick question... when I change oil in my vehicles, I like to:
1. drain the oil by removing the oil plug.
2. start the engine for 5 seconds to drain oil from the filter and oil pump, etc. More oil then drains out of the drain hole. There is also less oil dropping out of the oil filter when I remove it.
3. I remove the oil filter.
4. I then start the engine for 5 seconds to spurts out a bit of oil out the filter mount and some more drains out the drain hole.

Am I risking engine damage by doing this? Is it OK to run the engine for 5 seconds without oil in it? When one takes their vehicle to an oil change place, they just quickly drop the oil, don't let it drain much and then pop in a new filter and oil. I just don't think they remove enough of the old dirty oil... IMHO.

Comments?
 
Sponsored Links
  #2  
Old 07-05-11, 11:24 AM
daswede's Avatar
Member
Join Date: Jul 2003
Location: massachusetts
Posts: 2,215
I'm glad you are not changing my oil.
 
  #3  
Old 07-05-11, 11:29 AM
Gunguy45's Avatar
Super Moderator
Join Date: Dec 2007
Location: USA
Posts: 21,019
The worst times for an engine are at startup (and prob shutdown). You are really hurting the bearing surfaces by your method.

Warm the engine...drain pan and remove filter. The amount of oil left in the engine is miniscule. Install drain plug, new filter, and add oil. Drive happy.

ps...some people prefill the filter if possible.
 
  #4  
Old 07-05-11, 11:31 AM
Member
Thread Starter
Join Date: Jun 2003
Location: Canada
Posts: 164
5 seconds is going to damage bearing surfaces?
 
  #5  
Old 07-05-11, 11:34 AM
Member
Thread Starter
Join Date: Jun 2003
Location: Canada
Posts: 164
Why do people pre-fill the filter? Sounds like a way to get oil all over you...
 
  #6  
Old 07-05-11, 11:49 AM
Join Date: Jun 2010
Location: Canada (near The Motor City)
Posts: 611
You are probably right... keep doing it your way.
 
  #7  
Old 07-05-11, 12:06 PM
Member
Thread Starter
Join Date: Jun 2003
Location: Canada
Posts: 164
thanks for the support.... what do you other guys out there think? 5 seconds cannot cause any damage could it? There is still a film of oil in the bearings...
 
  #8  
Old 07-05-11, 12:17 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
No oil on a bearing is suicide for that bearing. Lifters need oil. Turbo's need oil. There ain't no way I'd start an engine without it being sufficiently full of oil.
That "film" is rubbed off with the first spin, then you are basically metal on metal.
 
  #9  
Old 07-05-11, 12:32 PM
Member
Thread Starter
Join Date: Jun 2003
Location: Canada
Posts: 164
Chandler - you are telling me that 5 seconds is going to inflict damage? I can't see it happening...
 
  #10  
Old 07-05-11, 01:00 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
You've been given sage advice. It's up to you if you want to chance bearing damage, not us. I've torn too many engines down in my earlier years where just dirty oil did damage. I cannot understand why you have to get every last drop of oil out at oil change.
 
  #11  
Old 07-05-11, 01:05 PM
Member
Thread Starter
Join Date: Jun 2003
Location: Canada
Posts: 164
I want to remove as much as I can, that is my thinking. I bet I get about 1-2 cups of oil out this way.
 
  #12  
Old 07-05-11, 01:28 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
What does the cup of oil cost, and what damage does it do to leave it in the mix? Compare to possible engine damage. Pricelesss.
 
  #13  
Old 07-05-11, 01:41 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA
Posts: 44,034
Originally Posted by Howitzer View Post
Why do people pre-fill the filter? Sounds like a way to get oil all over you...
Prefilling the filter means there are a few less seconds the motor goes without oil. I always prefill the filter, most of it's sucked up by the filter media so it really isn't all that messy. I generally spill more oil removing the old filter than I do installing the new one. The only vehicle I never prefilled the oil filter on was my old jeep - the filter was mounted upside down

I would never intentionally spin a motor with no lubrication! If you change your oil regularly there is noway that the small amount of dirty oil in your engine will have a detrimental affect on the new oil.... or the life of the motor.
 
  #14  
Old 07-05-11, 01:50 PM
ukrbyk's Avatar
Member
Join Date: Mar 2010
Location: USA/ Pacific NW
Posts: 3,301
not to get into quarrel...
here's how i change oil in my cars

1. 500 miles before oil change, pour can of Seafoan into crankcase. Then drive as usual. Cleans all debris etc in narrow passages
2. i buy cheapest oil in proper weight available, usually Walmart. they always have those deals on gallon canisters.
3. buy filter and regular oil
4. drain used oil, put drain plug back in, and refill with flush oil
5. run engine for about 15 minutes, or drive on it, with occasional revs to 2500 rpms.
6. drain oil. normally comes out pitch black.
7. replace oil filter, refill with quality oil.

that's it. takes time and is more expensive, but cleans very well, and flushes narrow passages without aggressive cleaners use.
 
  #15  
Old 07-05-11, 02:02 PM
Forum Topic Moderator
Join Date: Mar 2005
Location: USA
Posts: 44,034
ukrbyk, I can see doing that when purchasing an used vehicle but once regular oil changes are made I can't see any benefit for the extra work and expense. My wife's car as 146k on it, it's always had regular oil changes and while the oil will have color after 3k, it's a long ways from being black.
 
  #16  
Old 07-05-11, 03:00 PM
the_tow_guy's Avatar
Group Moderator
Join Date: Feb 2001
Location: SW Fla USA
Posts: 11,575
For howitzer, I don't know that there is a definitive answer except to say that although it may not be immediately noticeable, who's to say it may not have a detrimental effect over the long run? Problem is by the time you have 100,000 miles on it, if there is some extra wear and tear there's no way to undo it or even to know that it's there. Will 5 seconds cause damage? Maybe. Ten seconds? Who knows. How do you draw the line? Is 5 seconds okay, but at 6 seconds you're doing damage? For the 1 or 2 cups of oil (2 cups = 1/2 qt or roughly 10% of your oil volume) I don't see any benefit and there are potential risks. I always prefill the filter on the wrecker, but not on the Toys. The wrecker filter is vertical, threads up; the Toys are horizontal.
 
  #17  
Old 07-05-11, 07:55 PM
ukrbyk's Avatar
Member
Join Date: Mar 2010
Location: USA/ Pacific NW
Posts: 3,301
no matter what we say here, it will all go to personal beliefs and preferences. stuff we grew up with. experimented with. Daddy/Buddy showed us. for some, 3K miles oil changes are embedded and holy. i do mine well over 10K and am comfortable with it. my oil changes cost average $60, and I am VERY COMFORTABLE with this. i used to "ding" starter to spin engine too. what for? few drops of oil and potential to screw up something?
really, it's a philosophical question more than practical.
 
  #18  
Old 07-06-11, 04:50 AM
the_tow_guy's Avatar
Group Moderator
Join Date: Feb 2001
Location: SW Fla USA
Posts: 11,575
There you go. I do all mine, personal and wrecker, at 5k intervals. Easier on my brain to do the math.
 
  #19  
Old 07-06-11, 04:52 AM
Member
Join Date: Jan 2006
Location: Owen Sound Ontario Canada
Posts: 541
Howitzer
Running engine for 5 seconds without oil pressure will cause damage. For sure.
The oil system for the crank is more of a lift device then it is an oil system.
Oil from the oil pump causes a "hydrodynamic wedge" when oil is pumped and the crank shaft is rotating at sufficient speed. Sort of like water skiing.
With slow cranking speed and no oil pressrue to force the crank up it is metal to bearing contact. That will wipe the bearing.
Ive heard it said that 90% of engine wear occurs on start up and shut down.
Where I work we have "Jacking oil pumps" for the huge electric motors and the turbines. For use until the device has enough RPM and oil pressure combined to create and maintain the hydrodynamic wedge.
Maintenance of this hydrodynamic wedge is one of the reasons we change oil.
Viscosity. How thick the oil. Over time the oil will start to loose its viscosity and the hydrodynamic wedge will get smaller and develop more heat from "oil shear" which will degrade the viscosity more.
If you want to clean your engine more during an oil change you could do more of them or do like ukrbyk does
 
  #20  
Old 07-06-11, 01:53 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,968
If you want to do your turbo in, just shut it off after coming to a complete stop in the driveway repeatedly. It is turning about 10,000 RPM at that point and no oil pressure if you shut the engine down. I always let mine run a minute or so while I am fiddling with getting paper work together from the pax seat. At least the RPM has diminished somewhat at that point. It also lets the waste gate do it's thing as well.
 
  #21  
Old 07-07-11, 03:12 PM
Member
Join Date: Jul 2011
Location: USA
Posts: 9
While it comes down to personal preference, I would not recommend starting the engine while changing oil. All it takes is one main bearing to go dry and spin itself. Then you are looking at some serious repair costs. You valvetrain will be receiving almost zero oil when you start the engine. What if something unexcepted happens and you cannot shut the engine off in time?
 
  #22  
Old 07-14-11, 01:32 PM
Member
Join Date: Jan 2009
Location: SE Texas
Posts: 32
Some people are nuts. Millions of Cars if not hundreds of millions of cars have gone through millions upon million of miles with just normal drain and fill-change filter oil changes. Why try to reinvent the wheel?
 
  #23  
Old 07-14-11, 02:00 PM
Join Date: Mar 2005
Location: USA
Posts: 6,127
I just have local mechanic do it the normal old way and he charges only $8.00 for change and lube if I buy the oil and filter. Since the car has always used Mobil 1 (from day 1), he told me to go to Walmart and get a 5 quart jug because that is what he does for his Corvettes. - Not worth stocking in his garage.

I haven't driven that much lately, so I drove it in at 5,000 miles from the previous change and got a change after going from winter/spring to summer. The guy that drained it asked why I had it changed because it looked and felt the same as what he just put in. - The vehicle is 1999 GMC Jimmy 4WD with 170,000+ miles on it and the oil has never been below the full mark and not a single engine problem. Before I bought it at 24,500 miles, it was owned by GM and serviced at a GM (not a dealer) and Mobil 1was used for every change at almost exactly 3,000 miles for the first 24,000 miles.

Dick
 
  #24  
Old 07-17-11, 10:08 AM
Member
Join Date: Feb 2009
Location: USA
Posts: 323
Don't run your engine without oil in the pan, plain and simple.

If you are worried about leaving contaminated oil in the motor, pour about a cup into the oil fill and watch it push out a small amount of old oil from the drain. That's what I normally do but NEVER start a motor with no oil.

There have been some good posts here, one thing you need to keep in mind and I feel is extremely important.....when you start the motor up to pump out that remaining oil, you are losing your prime on the pump when you start it up again.

If you have never rebuilt an engine then it's hard to visualize but you need to pack the pump with vaseline or equivalent or at least spin the distributor to prime the pump....not sure if it's even possible on newer cars. Your 5 seconds has now turned into a longer duration.

The remaining contaminated oil will get filtered and diluted and will not be a problem, so don't try to pump it out.

You won't hear the knock right away without oil but once you do, keep in mind that rod is coming down with enormous force and has only an oil film measured in ten-thousandths, you bearing material is measured the same.....there's not much there.
 
  #25  
Old 07-18-11, 07:02 PM
Member
Join Date: Nov 2006
Location: Jersey
Posts: 526
Just my $.02

While I like your theory of squeezing out all of the dirty oil........."I" wouldn't do that and would just stick to dumping the oil and changing the filter while the engine is hot.
The cost of parts and labor to rebuild an engine are way to expensive to chance a spun bearing, scored cylinder walls or a rod flying through the side of your engine block. Even with the high cost of a quart of oil it's still way cheaper than new engine parts not to mention down time.

If you really want to squeeze out all of the dirty oil letting it drain overnight is playing it way safer.

With all of that being said it's far worse to run an engine without coolant than it is to run it without oil for an extended period of time although both are very bad........(here goes another discussion)
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes