Do you prime oil filter?

Status
Not open for further replies.
Joined
Oct 3, 2002
Messages
15
Location
SoCal
When changing oil, do you prime the oil filter with oil, or just install it dry?
I'm wondering since it seems to be a reasonable idea but I've never seen it recommended. What do you think?
dunno.gif
 
What I do: install it dry, run engine, check for leaks, park on a level surface and allow oil to drain back into pan, then check level and make a final top-up of the oil.

What is best to do: I'm not sure. Anyone else know?
 
Since I began changing my own oil again, I've always primed/prefilled my new filter. On my car, the oil filter hangs vertically, so it's easy. Is it best to do it? Yes. Is it absolutely necessary? No. Virtually none of the quickie-lubes or dealerships do it. And on a horizontal mount, you can only fill less than half of it anyway.
 
Yes, you're allowing unfiltered oil to flow into the engine, fresh oil, right from the bottle. I assume it is clean
grin.gif
 
I always fill the filter up! I did an experiment once and put it on dry and there was a noticeable difference in how long it took for the oil pressure to rise off the zero mark. With the filter filled it comes up almost instantly (although still not as quickly as it will on subsequent cold starts)
 
Does Cat. want you to have a good dry, cold start so you have to rebuild sooner or what?
confused.gif
 
Addendum to the above: I *can't* prime my filter, as it's a bottom-change, cartridge type. See the thread on the "BMW filter philosophy vs. other manufacturers."
 
quote:

Originally posted by Chris:
Does Cat. want you to have a good dry, cold start so you have to rebuild sooner or what?
confused.gif


You know that you carefully put clean oil into your filter. The Cat factory doesn't know what happens in the field, so they take the safer route. Priming the filter with clean oil is best, installing a clean, dry filter is second best, some moron filling a filter with oil plus whatever else falls in or washes off his dirty hands isn't good at all.

Ken
 
I don't,

I just just put the filter on and go. Unless your engine is shut down for days, your will have plenty of boundry lubrication on the moving parts until the fresh oil gets pumped through(UNLESS you change your oil when its 40 below)
 
quote:

Originally posted by msparks:
I don't,

I just just put the filter on and go. Unless your engine is shut down for days, your will have plenty of boundry lubrication on the moving parts until the fresh oil gets pumped through(UNLESS you change your oil when its 40 below)


Actually, some boundary additives(not all) will provide enough protection for an engine to endure a momentary dry start. The design of the engine first normally has some oil residue left in the bearing areas around the crank which prevents lower end noise when first cranking with a dry filter. Notice that normally it is the top end where the valves are clattering that suffers the lack of lubrication when this senerio is in play.

Boundary additives do not run off like the hydrodynamic property of oil, so normally it doesn't matter how long you may let it sit, it will still have that on the surface unless it has been exposed to open harsh enviorments such as weather and such, which will not happen if in a car.

Putting oil in a filter prior to starting an engine is a good idea provided that great care is used not to contaminate the oil going in. If you have a system like mine that lays on its side, you cannot put oil in prior to installing as it will just pour back out as you put it on the car.
 
Bob, even if your filter sits sideways, such as the one in my wife's car too, you can still add a little bit of oil. I typically add about 100ml or so of oil to her filter before putting it on. A little bit is better than nothing. I see no reason not to do it, why rely on boundary lube here when it takes only a few moments to fill up a filter, and it'll offer a slight bit of extra protection? Sure we are splitting hairs here, but it's just something that makes sense to do.
 
I think you missed what I said patman... I did say it is not a bad thing to do provided care is taken not to contaminate the oil going in, but you're right, you're splitting hairs as the little bit of oil you are putting in that filter, will amount to no wear protection when providing hydrodynamic lubrication as you still have to have oil pressure before you create that protection, and that only exists when the pump has pulled enough oil from the pan and created a backpressure due to the oils resistance of flow, then hydrodynamic can start to form.
 
Bob, what do you mean by contaminate the oil going in? How is it any different than when you're pouring that same fresh oil into the engine? I guess this is another reason I buy the fresh funnel for each oil change, that way there is less chance of that funnel being contaminated with anything. (such as dust that may have settled on the previous oil that was run through it)
 
More nits.
smile.gif


I get 7oz in a PL14670 mounted horizontally. The media is a great sponge. My PL30001 took over 16oz without spilling. If an oil pump moves 1.5GPM at idle (550RPM) that 16oz would mean 5 seconds on boundary protection. Seems like a long time even if it isn't working hard.

Anyway, I like to pet my dog when I feed him.
grin.gif


David
 
Status
Not open for further replies.
Back
Top