Prefilling oil filters: not good?

[ZZman]

It is good if you can do it.

Is it going to kill your engine if you don't?....NO

I am sure almost every Instant Oil Change place does prefill them.

 

[Kestas]

Originally Posted By: 97f150
I dont know what difference filling the filter from the exit port with "dirty" clean oil will make considering that the other at least 3-6 quarts are going to be dumped into the engine without the benefit of filtration anyhow.

Bravo. That hit the nail right on the head.

 

[Nayov]

I think I've heard it all now...I mean, the oil is dirty from the jug for real? I add oil to the big hole of the filter and roll it around until the pleats absord as much as possible.

 

[Newtonville]

It is better to prefill. It isn't necessary to prefill, as in making much real word difference in the car ownership experience, but it is better. Most people who think about oil enough to find BITOG interesting are perfectionists about oil and want to do the better things. My question is why people with all kinds of false ideas find it necessary to act as experts and write articles.

 

[EricF]

Even on toyota's with the filter mounted above exhaust manifold, where it faces downward, I preoil that filter, just to get the filtering media wet so when the initial burst of oil pressure hits the filter, the media is already wet.
Yes, it sounds weird, but if I can't fill an oil filter up, I will at least soak it with oil so it'll be readied.
I'm probably following an old mechanics myth, but some of them I believe in.
But I always fill oil filters, just to take up pressure seconds of no oil flow to me is just an advantage, also makes it easier to top off iniitally.

 

[crw]

Just because there is "no cleanliness standard for new oil", that doesn't mean that it isn't clean. If your choice of oil bothers you, then that's where you need to look. lol

 

[Kestas]

To be fair, there is some residual dirt in commercially supplied fluids. My colleague received a free sample pail of Dex-VI when it first came out. Being anal, he filtered all the fluid through one-micron filters before putting it in his truck. He showed me some of the filters. I'm not that anal, so I wasn't aghast with the dirt, but it's there.

So, in my opinion, prefilling filters is a good idea, but don't worry about the dirt in commercially available fluids.

 

[ARB1977]

The Tacoma doesnt get prefilled because of the downward angle...but the jetta does.

 

[panthermike]

I also prefill filters when possible. The Corolla's are really easy as they sit vertical. My brother's F150 filter sits nearly sideways though, as does the filter on another Bro's Taurus.

 

[oldmaninsc]

Originally Posted By: callbay
I often read here on BITOG about vehicles with 200,000 miles 300,000 or even over 400,000 miles on them. I'll bet that most of them never prefill the filter. Can anyone back me up on this?
If you have ever tried to prefill a hard to get to filter, you will never do it again.


Not me. I have a vehicle with over 200K miles on it. I have prefilled the filter from day 1.

 

[froggy81500]

never heard of anything bad happening from pre-filling a filter other than maybe spilling oil out of it.

unfortunately I can't prefill mine on the ecotec, it uses a cartridge filter or I would.

 

[dave123]

Picture all that unfiltered oil being poured over your valvetrain as it goes to your oil pan. Get real people

 

[labman]

There has been inconclusive discussions of the solids in the bottles of oil. I know YB Pennzoil has it, and I suspect such nectar of the gods such as GC, Royal Purple, Mobil 1, Amsoil, etc. has it too. What is it? Could be insoluble additives. They drain to the crankcase and are then stored in the oil filter until used up.

I used to prefill, but quit. There is a difference between dirty oil running over the camshaft and valve springs and being pumped through the bearings. Oh, what about all the oil that picked up dirt working through the engine and runs out into the cam covers?

 

[Steve S]

Or when the engine is first started and the filter is bypassed untill the oil pressure on both sides of the element is some what normal.

 

[froggy81500]

Originally Posted By: dave123
Picture all that unfiltered oil being poured over your valvetrain as it goes to your oil pan. Get real people


wow. the most obvious detail and it hadn't been mentioned before.

great point.

 

[Ed_T]

Some manufacturers require pre-filling. Why would anyone want to cause oil starvation?

Considering the pi$$-poor filtration most OTS consumer oil filters provide, any "dirt" is not going to make a whit of difference.

 

[97f150]

Originally Posted By: froggy81500
Originally Posted By: dave123
Picture all that unfiltered oil being poured over your valvetrain as it goes to your oil pan. Get real people


wow. the most obvious detail and it hadn't been mentioned before.

great point.


Has been mentioned twice before.

 

[labman]

Along with the idea that running over the top of the camshaft is different from being pumped through the bearings.

 

[RacerE7773]

Originally Posted By: Nayov
I think I've heard it all now...I mean, the oil is dirty from the jug for real? I add oil to the big hole of the filter and roll it around until the pleats absord as much as possible.
So do I. When I had my '00 Cavasmear (good riddance, but that's a different story) it had the filter horizontally up in the right center of the block, so prefilling I'd tried only once in the 9 1/2 years I had it. Our '03 Impala is at an angle so it's easier to do that with.

 

[Virtuoso]

I'd pump new oil from the bottle through my bearings all day.

Would be interesting to see just how 'dirty' new oil really is though!

Oh...I prefill, too. When possible. I must admit though, with the smaller filters (like the PF46 on my Malibu) it dosent seem to matter much.