Do you pre-fill your oil filter and, if so, are we doing it right?

[aussiblue]

While this video (https://www.youtube.com/watch?v=P6MLDH0zTpw&t=187s ) about Cat Diesel oil and petrol filters, the principles are the same for the oil filters on our petrol driven vehicles and it does raise some interesting questions. If we are filling via the large spin on hole on filter we are filling at the outlet side and are probably doing very little in terms of priming the oil pump or oil lines. Also if there is a foil cap on the oil pack, or anything else in the oil that shouldn't be, it's going to go into the engine without being filtered. Even if we keep filling the filters at the outlet hole as the level subsides it is probably just being soaked up by the filter media in a sponge like fashion rather than passing to the filter inlet side. So do we pre-fill and if so should we be doing it with a small funnel one of small perimeter inlet holes?

[aussiblue]

PS if you think the chance of getting a foil cap in your oil is low I must tell you about my experience with a well known brand of upper cylinder lubricant petrol additive in my LC Lancer. It was probably nearly 20 years ago, but in any event, while I was careful to remove the seal before pouring the additive in the tank I ended up with a daisy chain of around 12 seal in the tank. Obviously something had got wrong in the filling plant and this daisy chain of seals had ended up in the container of upper cylinder head lubricant. These seals had two layers: a white waxy papery layer and a transparent layer. The two layers separated in the tanks and the paper bits got sucked one by one and rolled themselves up to get through the line as far as the fuel filter where I found them. The clear plastic bits broke into several smaller daisy chains that kept blocking the fuel inlet pickup pipe in the tank so that the car stalled for lack of fuel but then restarted when these seal dropped off the inlet pipe. You can imagine the fun to had finding a dozen invisible transparent seals in a tanks with baffles running in both directions and not really knowing how many seals I was looking for. It was a laborious task of going through the routine of putting a gallon of fuel in the removed tank shaking it about, emptying it through a mesh filter to find those seals and repeating this 20 or 30 times before crossing my fingers and reinstalling the tank.

[aussiblue]

Also http://beamalarm.com/Documents/prefi...tructions.html and http://www.widman.biz/uploads/Corvair_oil.pdf

23. When changing oil, always change the oil filter. If you pre-fill your filter, do it with extreme caution. Any oil that goes into the center will reach the engine unfiltered (and there is no cleanliness requirement for new oils).

[GASWAGON]

No need to pre fill oil filters............Just spin on and fill with new engine oil.

Oil pump in sump will quickly fill the filter after starting.

Turn engine off then re check engine oil level.

Z9's for older Falcons only hold about 500ml of oil and the Barra "Ryco R156" filters hold much much less.

Absolutely no need to pre fill oil filter on a Falcon!!!

[Peter B - CV8]

I pre-fill via the centre hole, give the oil a chance to absorb/wick through the filter material & then add a little bit more. When first starting, the oil pressure light goes out almost immediately - whereas if the filter is installed empty, the light remained on for a couple of seconds. To my mind, it's those "couple of seconds" where the most engine damage is done.

[solarite_guy]

^^^^ +1

I do the same as CV8 for street driven engines, using Wix filters.

For race engines I use System 1 filters and prime the oiling system. I'll also prime the system if the engine has sat a couple days.

[Maka]

I pre fill around 3/4 full through the centre threaded boss hole with a small funnel taking care not spill any oil that may permiate back through the little side supply holes & then the adbv. No start up rattles & up to pressure faster when done this way imo.

cheers, Maka

[d@rk51d3]

Same here.
Always lube the hole.

[Tassie f100]

Been filling filters via the centre hole for 50 years without any problems.Really isn,t that important because all moving parts in the engine will still have a coating of oil from before the service

[GasoLane]

The oil filter on my (non Ford) car is upside down, so it could get a little messy if I tried to pre-fill it

[d@rk51d3]

Pack it with grease.

[solarite_guy]

Time to get the priming tools out.

[Trump]

Originally Posted by GasOLane

The oil filter on my (non Ford) car is upside down, so it could get a little messy if I tried to pre-fill it

Same here, the cartridge element doesn't lend itself to pre-filling

[Maka]

Originally Posted by Tassie f100

Been filling filters via the centre hole for 50 years without any problems.Really isn,t that important because all moving parts in the engine will still have a coating of oil from before the service

Older hi km engines will benefit imo from prefilled oil filters, less /no knocking on startup means more kms out of crap worn motor lol!

cheer, Maka

[aussiblue]

Some other forums also suggest that another reason not to pre-fill at the outlet hole is there is no specification or requirement that new oil to be clean and free from solid contaminates and as oil is being poured in the outlet hole any such contaminates will enter the engine and cause damage. I would be interested if site sponsor Mainlube and confirm if this true or not so will PM him.

[danzvtil]

Don't see the point really, it would take 2 seconds at start up for the new filter to fill up with oil, the engine doesn't starve for those 2 secs as it's already oily. But if it floats your boat, then go for it.

[roKWiz]

I definitely have to pre fill the filters on one of the Ford Traders as it came with not 1, not 2 but 3 filters. Two of them are Luberfiner type remote filters which roughly take 5ltrs by themselves, the other is a standard spin on.
I have no idea why this thing has so many remotes but its the coolest running Trader I have. One is a toilet roll 4M Luberfiner system. Yes it takes 4 toilet rolls. weird. (google it)
Biggest problem with this set up is, its easy to overfill with oil, when I bought the truck I stopped on the 2 day trip home to check the oil and it showed nothing on the dip stick. I thought WTF and filled it to the full mark but found it blew oil everywhere until I drained it back showing almost nothing on the stick (after researching these) where its supposed to be in this case. Weird !

[commodorenutt]

I pre-fill the FG almost full, before I jack it up & dump the old oil. By the time it's needed, it's about 2/3 full after soaking through, and it does make it easier to dip your finger into it & wipe some oil around the rubber seal. You probably can't go any more than 3/4 full on the FG 6 because of the fiting angle.

The VE 6L however, the canister is vertical, so I prefill it all the way, and top it up a little more after the soak time.

That being said, on Holden cast iron V8s (304/308 etc) the oil filter sits horizontal, and can't be pre-filled, as it would all pour out as you install it, so I never pre-fill them.

[aussiblue]

By the time it's needed, it's about 2/3 full after soaking through,...

Apparently it doesn't soak through to the inlet side it just gets absorbed by the filter media.

[snap0964]

I prefill most of the the time.
What I always do though is pull the CT LP fuse and motor the engine over for around 15 secs, refit the fuse quickly and then start the car proper.

Obviously the oil pressure is very low, but at least it starts circulation before proper start up.
Am I wasting my time ?

[aussiblue]

I have found one (slim) argument on another forum for pre-filling at centre outlet hole only. It is suggested that it prevents filter media damage by equalising oil pressure on both sides on the filter media preventing filter media damage (blowout) from the inrush of oil when the engine is first started. I not convinced on that one... though perhaps on those low quality FRAM filters with the small amount of filter media and cardboard endcaps. See https://www.youtube.com/watch?v=b9pVxaH7Vcs

[commodorenutt]

In a spin-on oil filter, the media is supported by the perforated central tube - it doesn't need oil to "equalise" the pressure - it's designed to withstand high pressure in one direction (reverse the flow & you'll blow the filter media out). It's basic filter anatomy 101.

(OK, I may have a little more knowledge on filtration than others, as I sit beside a guy who is the category manager for the AU/NZ arm of one of the largest (in $$) filter parent companies in the world...)

[aussiblue]

As I said I wasn't convinced on that argument.

[aussiblue]

it beside a guy who is the category manager for the AU/NZ arm of one of the largest (in $$) filter parent companies in the world..

Perhaps ask him about pre-filling on the outlet side and if when you do this the oil then soaks through to the inlet side or is simply soaked up by the filter media dropping the initial fill level. Of course it might depend on the material and quality of the filter media.

[Itsme]

I've always been pre-filling oil filters by the centre hole if allowable depending on what position the filter sits on engine, never had an incident yet doing this procedure over 45 years.
The odds of any foreign material entering the filter would be negligible unless you are really careless or using dirty equipment.

[redxm]

Ive prefilled filters for years on falcon 6's. They tend to rattle for a second or two if you dont.

[GO FURTHER]

Reading through this thread, it has confirmed to me, that most of the general population don’t understand the difference between “dry” and “wet” fill.

They decide to look up their car manual to see how much new oil to buy so they can do an oil and filter change.

Mr Smith has an FG XR6 and this owner’s manual states 6.8 litres with filter change.

So he walks into Supercheap and buys 7 litres of oil and a new oil filter.

Goes home, drops his oil and filter, then fits new filter and pours some oil into it.
Then pours the balance of the 6.8 litres needed into the engine.

Checks dipstick after running car for a few minutes and letting it drain into the sump again after 20 minutes.... And “oh no! .... I’ve overfilled it’.

What Mr Smith does not realise is an oil change is a “wet” fill and unless he rebuilds his engine.... He will never ever be doing a “dry” fill.

What Mr Smith failed to understand is Ford and many other car manufacturers quote engine oil capacity when the engine was built “completely dry” of any oil.

Everytime Mr Smith changes his oil and filter, even if he left it dripping out the plug hole all night before putting in the new oil.... There will still be between 500ml to 800ml of old oil sitting in the galleries and coating engine parts.
You will never get it all out in a normal oil change.

Each time I drain my oil and change the filter in my FG XR6T and I’ve done it 16 times now, I have never drained more than 6 litres including whats in the old filter.

So for the few seconds it takes for your new oil filter to fill up with oil, if you don’t prefill it.... There is still going to be up to 800ml of old oil coating the engine internals to prevent any damage.

Now if you just rebuilt your engine, and were doing a “dry” fill... Then prefilling your oil filter would be an advantage.

[Silver Ghia]

Originally Posted by GO FURTHER

Reading through this thread, it has confirmed to me, that most of the general population don’t understand the difference between “dry” and “wet” fill.

They decide to look up their car manual to see how much new oil to buy so they can do an oil and filter change.

Mr Smith has an FG XR6 and this owner’s manual states 6.8 litres with filter change.

So he walks into Supercheap and buys 7 litres of oil and a new oil filter.

Goes home, drops his oil and filter, then fits new filter and pours some oil into it.
Then pours the balance of the 6.8 litres needed into the engine.

Checks dipstick after running car for a few minutes and letting it drain into the sump again after 20 minutes.... And “oh no! .... I’ve overfilled it’.

What Mr Smith does not realise is an oil change is a “wet” fill and unless he rebuilds his engine.... He will never ever be doing a “dry” fill.

What Mr Smith failed to understand is Ford and many other car manufacturers quote engine oil capacity when the engine was built “completely dry” of any oil.

Everytime Mr Smith changes his oil and filter, even if he left it dripping out the plug hole all night before putting in the new oil.... There will still be between 500ml to 800ml of old oil sitting in the galleries and coating engine parts.
You will never get it all out in a normal oil change.

Each time I drain my oil and change the filter in my FG XR6T and I’ve done it 16 times now, I have never drained more than 6 litres including whats in the old filter.

So for the few seconds it takes for your new oil filter to fill up with oil, if you don’t prefill it.... There is still going to be up to 800ml of old oil coating the engine internals to prevent any damage.

Now if you just rebuilt your engine, and were doing a “dry” fill... Then prefilling your oil filter would be an advantage.

Mr Smith actually is correct in pouring in 6.8 litres of oil..

"owner’s manual states 6.8 litres with filter change." means that is the oil quantity required to refill the engine after draining the engine and changing the filter.

As opposed to changing the oil without a filter change, which is perfectly fine in some situations.

The oil quantity required to fill an newly rebuilt engine including filter, where there is no oil in the engine at all, will be stated in the manual as "dry fill" quantity.


One thing however, is that the quantity of oil can vary from what is stated in the manual, to get the oil level to the full mark on the dip stick after the engine has run. It is best to underfill by 1/2 a litre, run the engine for 1/2 minute, shut off engine then wait 10 minutes for the oil to run down from the top of the engine before checking the oil level and topping up as necessary to the full mark.

[TICKFORD220]

Always put as much oil into the oil filter without spilling it while installing the filter,dont read too much into it because doing this is a lot better than not prefilling the oil filter.Ive always used the centre hole and never had an issue in 23 years roughly.
I will add one comment,adding oil or servcing a motor is a hard task even for a mechanic apparently since the last clown who serviced the car before I bought it put 2 litres too much oil in my bf xr6......Really how bloody hard is this task?
When you can hear the crank splashing in the oil its not a good sign...................(rockingham mobile mechanics)

[d@rk51d3]

Originally Posted by TICKFORD220

I will add one comment,adding oil or servcing a motor is a hard task even for a mechanic apparently since the last clown who serviced the car before I bought it put 2 litres too much oil in my bf xr6......Really how bloody hard is this task?
When you can hear the crank splashing in the oil its not a good sign...................(rockingham mobile mechanics)

Had my work D-Max done in Adelaide, at the dealers........once.

Checked it a few days later, and oil level was barely touching the dipstick.

Filled her up, and done it myself ever since.