i always fill the filter with new oil and rotate it around to get the air out. even a 90 degree filter and its paper element will hold some oil. where is the dry start happening that i see some talking about and what is the way around the dry start?
dry starts after oil change
- Thread starter montero91
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I often prefill my filter the day before I do an oil change so that the oil really soaks into the filter media and then add a bit more oil to the filter so that it is topped off on the day of the oil change.
the dry start is mainly caused by not pre-filling the filter. When I was young, foolish, and lazy, I never pre-filled and was treated to valvetrain clatter for several seconds until oil pressure came up.
Now I always pre-fill, and both my cars allow 80-90% filling with no spillage. Oil pressure light turns off almost instantly and no scary noises. Given the ease of pre-filling, I can't think of a reason not to do it.
I always cringe when the term "dry start" is used to describe the start-up after an oil change.
If the oil change only takes an hour, rather than a week, all the components in the normal lubricating stream will still retain a film sufficient for lubrication.
Some noise, such as valve train clatter, can be expected as the intial flow is driving air out of the system.
I can think of one major reason not to pre-fill: it is pointless.
You just finished pouring up to 5 quarts of oil into the top of your engine, probably directly onto the valve train area. Where did it disappear to?? Just how fast do you think it flows south? and what about all the oil film left behind (which is all you have normally)?
Many of the MOST reliable and long-lived engines' filters cannot be prefilled.
You still have all the oil passages between the pump and the filter, and the passages between the filter and the top of the engine that are full of air. They don't count? (these vary with location and effectivity of the anti-drain back valve, if any)
you could just start the engine immediately after pouring in the final bit of oil while it is still flooding the valve area. That will purge all the air from the pressure side of the system while there is still plenty of oil on the topside.
but it won't make any difference.
quote:what? all the parts don't move just because the plugs don't fire???? hello......
Originally posted by rg144:quote:Don't let it actually start. Instead, pull the coil wire and then crank engine to let the oil pump fill the filter.
Originally posted by montero91: what is the way around the dry start?
quote:Don't let it actually start. Instead, pull the coil wire and then crank engine to let the oil pump fill the filter. Then are you not adding raw gas to the new oil you just put in
Originally posted by rg144:
![[I dont know]](/forums/graemlins/dunno.gif)
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Whimseyquote:Sorry for any confusion - it's a recommendation for oil changes I've seen a number of times. Engine parts are moving (including oil pump), but at low RPMs - and no combustion sending pistons flying. And whatever fuel gets past rings will easily evaporate first trip.
Originally posted by kenw: what? all the parts don't move just because the plugs don't fire???? hello......
quote:All my engines are V's, so the oil dumps out on the valvetrain on one side only. It does disappear south quite quickly, I've found, and yes there is surely an oil film left. Wheter this film is sufficent lubrication or not is the question. I will continue to pre-fill, since I complete this as the old oil is still draining and frankly there isn't anything else to do at that time. Plus, I want to. And we live in a country where I can pre-fill my filter, if I so choose.
Originally posted by kenw: You just finished pouring up to 5 quarts of oil into the top of your engine, probably directly onto the valve train area. Where did it disappear to?? Just how fast do you think it flows south? and what about all the oil film left behind (which is all you have normally)?
![[Cool]](images/icons/cool.gif){kind=icon}
When the police drive by my garage and question my pre-filling, then I will begin to become concerned.I have a separate switch for the fuel pump relay as my home made security device. Crank the engine for about 10 seconds at about 100 rpm or whatever the starter can manage while the oil system pressurises. Then switch on the fuel pump. The real wear happends with you use a filter without a high quality anti drain back valve. The MANN Volvo filters excell in this respect.
I'll take oil pressure two seconds sooner for $0, Alex
I remember I never prefilled the Filter and Whenever I started it up dry, and it had a aweful Friction whining sound. so for now on , i always prefill.. no more awefule whingin
When the police drive by my garage and question my pre-filling, then I will begin to become concerned. [/QB][/QUOTE]
Where do you live so I can call them. I always prefill my filters, just out of habit I guess, the only reason that I started doing that is it gave me something else to play with while changing my oil. It also makes it look like you are doing when changing oil in female friends cars too. ![[Big Grin]](images/icons/grin.gif)
how do you prefill a filter on a 05 tacoma prerunner sr5? the filter is upside down!!!
Bill in Utah
Staff member
quote:You could just get the media damp by prefilling a day before and drain then install. This way, the oil is quicker to get through the media. But, I ONLY buy cars that have the Oil filter in the correct position and easy to work on!
Originally posted by sunruh: how do you prefill a filter on a 05 tacoma prerunner sr5? the filter is upside down!!!
![[Eek!]](images/icons/shocked.gif){kind=icon}
So far, this mindset has worked for me with the exception of my 1998 Honda Accord.. ![[Dummy!]](/forums/graemlins/twak.gif)
(We only kept that car 18 months as my wife and I disliked it..)
And I do prefill my filters... ![[Razz]](images/icons/tongue.gif){kind=icon}
I have some cars that I work on for the Family and I'd love to meet the guys who designed those engines! ![[Dual]](/forums/graemlins/itschy.gif)
(1993 Ford Exploder with 4.0 V6 for one..)
Take care, Bill ![[Coffee]](/forums/graemlins/biggthumbcoffe.gif)
You guys obviously have not had a 4.6L V8 Thunderbird. That thing is a pain to wiggle the filter into position.
Most newer cars will NOT inject fuel if the throttle is to the floor during cranking. This is how they clear a flooded engine.
So I just pull the floor mat and put my foot to the floor and crank for 10 sec or so.
No fuel is injected, the engine cranks over slowly and pressure builds.
I then let my foot off the throttle and it starts right up, all quiet like.
T
I don't think it really makes much difference. On two of my vehicles, the filter goes on horizontally and pre-filling it is impossible, and the oil pressure comes up pretty fast. Just don't depress the accelerator when you start and the oil film left behind from before the oil change should be sufficient, particularly if are only changing the oil every 7000 miles or so.
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