Do You "Prime" Your Oil Filters Before Installing Them ?

[AZjeff]

Originally Posted by atikovi
... And how do you introduce contaminants when you fill the filter with new oil any more than when you add the oil through the fill opening?


Good catch and I think I know what the answer might be. So someone is saying there are particles of something in a new bottle of oil large enough to be caught in an oil filter?

 

[Lowflyer]

Originally Posted by billt460
By "prime" them, I mean do you add oil to the filter before you screw it in place?
EVER. It reduce by me the time, in which the hydros clatter much louder on first start after oil change, about 3/4 ("felt").

 

[TiGeo]

No b/c, it will make zero difference in the life of my engine and it's base-down top-mounted on my car anyway..ahahahah

 

[Eddie]

I always prefill. Ed

 

[supton]

No. I used to, but I'm not sure it matters that much. Isn't that what the some of the additives are for? It's not like the bearings are bone dry at startup, and at startup the engine isn't at load nor hot. Yeah I can hear a bit of clatter from lifters or VVT (?) but goes away after a second.

 

[demarpaint]

If the filter is located in a position where it can be pre-filled without spilling, yes.

 

[WyrTwister]

I have been known to be a putz , from time to time .

My luck is , if I " primed " the filter , I would drop it trying to get the threads to start & would end up with a much larger mess that I started out with . :-(

Question though , our 2015 Chevy Sonic 1.8l has a plastic oil filter cap . That screws into a metal " lower cavity " . I guess I might be able to pour some oil into the " lower cavity " ? I do not know if that oil would drain out through the internal oil passages ?

 

[carviewsonic]

I've pre-filled filters for so long now, would feel like negligence not to do it.

 

[4WD]

The first few ounces poured in the center hole goes directly to bearings or other parts.
(Oil is pumped into the outer ring of small holes, out of the middle)
Not sure what they found in the new oil.

 

[69GTX]

For those doubly OCD, you can filter your oil by hand before using that to pre-fill your filter and remove "rogue" contaminants. Should only take an extra couple of minutes. Note, I've never gone that far.

By adding fresh oil through the filler cap nearly all the oil drains into the sump and eventually finds the oil filter before making its way to the bearings and other critical wear surfaces. So "rogue" contaminants added to the engine this way is a non-matter. But if you want to be ultra safe, go ahead and and pre-filter this too. And while we're at it there are probably leftover manufacturing particles in your new oil filter. Those should be flushed out with a light, clean oil (pre-filtered of course). I think that's OOOOCD.

 

[LotI]

Originally Posted by atikovi


Who is Jim Allen and what is "virgin oil"? And how do you introduce contaminants when you fill the filter with new oil any more than when you add the oil through the fill opening?

What? You've posted thousands of times and been here for 9 years and you don't know the name Jim Allen? Wow!

He is one of the most knowledgeable posters that has ever been here. He's a "done that" kind of researcher. You(and everyone) needs to read some of his contributions to this forum. I see his and Molakule's posts about automatic transmissions as the gospel.

 

[Linctex]

Originally Posted by billt460
I know a horizontal mount won't allow for this.



You would be surprised how full you can get them.

If you don't have any obstacles in the way, I can get one 80%-90% full and quickly mate it to the threaded nipple without spilling a drop.

Otherwise, I fill at least 50% full (minimum).

The difference is always a couple seconds difference for oil pressure to come up.

 

[SlavaB]

Any scientific proofs that you still need to prefill? Every modern spin on I've seen has a "don't prime/prefill" instruction on it. I don't believe that an engine benefits from this ritual, there is enough of oil film left on the components when you drain the oil

 

[Sayjac]

Where practicable, yes. That said, I'll admit it's mostly a 'feel good' thing to reduce start up rattle time. But that's what DIY all about, preference available.

 

[ARCOgraphite]

This prefill question is asked about every two months.

Subaru Specific ( FB engines ):
Our Subaru filter is base down and the engine dry starts after EVERY overnight sit. That filter is empty. Proven every time I've done and oil change on it. Also Previous FB25 in our Forester (s). You can prim the system directly thru the inlet and outlet holes in the mounting area during and oil change.

General :
Filters on many cars are tiny now with barely a cup capacity.

I suggest 1/2 - 2/3rds of the canister prefill - but no more than that. Leave some air space

With a full filter, It could be an impediment to certain oil pump designs priming ability.

These few oz. of oil in the filter and "in the way" may also produce a gunshot of an oil slug caused by a column of air compressed to high pressure in between the oil exiting the filter can and the oil pump You have heard hydraulic water hammer at your house under similar pressures. WHo knows what adverse effects this could have on VVT systems and HLA. This air column is typically not present on normal day-to-day wet starts.

Trucks:
On large truck filters I would prefill 2/3rds - 3/4.

And if you are really concerned, Prime the engine thru the dist drive shaft sithe the dist removed.
(Hot Rodders with certain classic engines only need apply here )

In summation, It is OK to prefill, but not all the way. The Tea cup filter on many engines it will like produce no benefit and may be troublesome.

-Ken

 

[atikovi]

Originally Posted by LotI
Originally Posted by atikovi


Who is Jim Allen and what is "virgin oil"? And how do you introduce contaminants when you fill the filter with new oil any more than when you add the oil through the fill opening?

What? You've posted thousands of times and been here for 9 years and you don't know the name Jim Allen? Wow!

He is one of the most knowledgeable posters that has ever been here. He's a "done that" kind of researcher. You(and everyone) needs to read some of his contributions to this forum. I see his and Molakule's posts about automatic transmissions as the gospel.


HAHA, there must be thousands of posters on this forum. Can't know or remember each and every one. Is there a sticky about him somewhere to read?

 

[Job]

Originally Posted by 2015_PSD
I used to on filters that would allow it until Jim Allen and I collaborated on some particle testing some years ago and discovered that virgin oil is not as clean as one might think.

In essence, by filling the filter, one is potentially allowing oil into the engine that may have contaminates which could be large enough to cause a wear streak in a bearing or the like.


What kind of particles? There is organic matter floating in air in rooms. Refineries don't bottle new oil in lab clean rooms. I don't believe there is anything in new oil that would scratch a bearing without seeing proof. Pouring new oil into an engine exposes it to air dust, and all the particles the rather poor full flow filters we use haven't taken out. Let's don't mention funnels and what they hold.

 

[ARCOgraphite]

Originally Posted by ARCOgraphite
This prefill question is asked about every two months.

Subaru Specific ( FB engines ):
Our Subaru filter is base down and the engine dry starts after EVERY overnight sit. That filter is empty. Proven every time I've done and oil change on it. Also Previous FB25 in our Forester (s). You can prim the system directly thru the inlet and outlet holes in the mounting area during and oil change.

General :
Filters on many cars are tiny now with barely a cup capacity.

I suggest 1/2 - 2/3rds of the canister prefill - but no more than that. Leave some air space

With a full filter, It could be an impediment to certain oil pump designs priming ability.

These few oz. of oil in the filter and "in the way" may also produce a gunshot of an oil slug caused by a column of air compressed to high pressure in between the oil exiting the filter can and the oil pump You have heard hydraulic water hammer at your house under similar pressures. WHo knows what adverse effects this could have on VVT systems and HLA. This air column is typically not present on normal day-to-day wet starts.

Trucks:
On large truck filters I would prefill 2/3rds - 3/4.

And if you are really concerned, Prime the engine thru the dist drive shaft sithe the dist removed.
(Hot Rodders with certain classic engines only need apply here )

In summation, It is OK to prefill, but not all the way. The Tea cup filter on many engines it will like produce no benefit and may be troublesome.

-Ken


How about that little triangular piece of foil from the cap that finds its way in.

 

[opus1]

Short answer, no; not on the current fleet.

Long answer, when I had my S-15 Jimmy 4x4, the front driveshaft's u-joint was directly underneath where the filter mounted to the engine, so GM put on a remote filter which sat behind the left headlight, and the filter mounted vertically with the opening facing up. It used a PF-52 filter so I was able to get a lot of oil in there before I put the filter on.

 

[exranger06]

Originally Posted by Linctex
Originally Posted by billt460
I know a horizontal mount won't allow for this.



You would be surprised how full you can get them.

If you don't have any obstacles in the way, I can get one 80%-90% full and quickly mate it to the threaded nipple without spilling a drop.

Otherwise, I fill at least 50% full (minimum).

The difference is always a couple seconds difference for oil pressure to come up.



Yup, I also prefill on horizontal filters and don't spill a drop.
Originally Posted by SlavaB
Any scientific proofs that you still need to prefill? Every modern spin on I've seen has a "don't prime/prefill" instruction on it. I don't believe that an engine benefits from this ritual, there is enough of oil film left on the components when you drain the oil

I've never seen that warning on any filter.

I've heard that some large trucks or heavy machinery NEED to have their filters pre-filled, since the filters are so large and hold up to a gallon of oil. If you don't pre-fill them, the engine will starve for oil long enough to cause damage. That's just something I heard a long time ago; not sure how true it is.