Do you prime oil filter?

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quote:

Originally posted by MolaKule:
I prime as well for most cars unless the dumb things are over 45 degrees or horizontal.

Mines 45 degrees too! LOL! I didn't see this posted and just thought I would add this-

If you own a diesl engine, the oil filter MUST be primed!
 
It's the diesel's fuel filter that must have all the air purged from it.

I've changed many Cat oil filters that are impossible to pre-fill because of their mounting position. I wouldn't design an engine that way, but Cat did. Of course, I'm not in the spare parts business.

Ken
 
Speaking of contaminating fresh oil, have any of you looked closely at your new filters, fresh out of the box? Try taking a lint free rag and wiping the end of the filter where the oil goes in and out. The threads too. I have often found a film of oily dirt and machining burrs on new filters. I used to use a brand called Harddriver. Each filter came individually shrink wrapped so it stayed clean from the factory. Unfortunately, they don't appear to be made anymore. Now I always give the filter a once-over to be sure I'm installing a clean one.
 
Can at least soak the paper a few times and let it absorb all it can.
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Why not install the filter dry, remove the fuse for the ignition and crank the engine a few times to get the oil pumped through a bit.

Then replace the fuse and start it up.

Sounds like too much work. I've never primed my oil filter - I just install it and go.
 
Prime mine IF the filter is vertical.....pretty darn hard when it's a 90° mount
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I always prime a remote dual mount vertical - the oil has a LONG way and two filters to fill - that could be a lot of time with no lube. When primed it moves a lot faster!
 
When I change my oil right as soon as I dump the last quart of oil, I put the crankase cap back on and start the engine. I have never primed the filter simply cause I've never heard of it until I read this discussion. However, I think that if you start the engine immediately after adding the last quart in and let it idle for 30 or seconds thats at least almost as good as priming the filter. Sure the pressue does take longer to build up than by priming the filter, but I think part of that is cause some of the new oil hasn't drained to the pan yet and is still in the engine, probably towards the bottom end by the time you start it. Either way, I've never had an engine tick or anything like that by not priming the filter, so I don't think it hurts anything by not doing it. However, next oil change I will prime it just to see how much quicker it is at building pressure.
Jason
 
Jason,
Inside your engine (to state things simply) you have three kinds of oil passages. You have oil supply passages. You have the actual bearing surface oil clearances. And you have oil return passages where the oil drains to the sump.

Pouring oil into the filler tube just allows it to drain into the sump. It's not lubricating anything, except maybe the one or two pieces you pour over.

Pre-filling the filter probably isn't necessary, but it just might help an engine live longer.

Ken
 
Ken,

Hmmm, didn't know that about the passages. I do have a question though. Does priming the filter help those dry starts when changing the oil all that much? The reason I ask is that the oil filter on my Jeep Grand Cherokee is right next to the pan and I don't see how it would make much difference in terms of the oil in the filter getting up to the lifters sooner than oil in the pan. Like I've said before the engine has never made any valvetrain noise by not priming the filter when I start it up after changine the oil. not trying to argue but im just curious
Jason
 
Thanks Jeeper...

for the Harddriver link. I've done umpteen searches for them and got nothing but dead links at best. They used to be available from a place in the Chicago NW suburbs for $10, now I see they've jumped to $20! They're good, but $20 is awfully high.
 
Jason, first off, it isn't a huge deal. Some of us are being picky. We could easily get into the "millions of cars run without doing it" argument.
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That said, a dry stock filter size of maybe 10-12oz means about 4 seconds on boundary protection before the filter fills and oil moves up higher in your engine. My oversize filter takes ~16oz to prime which tells me pre-filling is more important the larger the filter.

Engines vary, but you get the idea. Pre-filling definitely shortens the time at zero oil pressure where you're depending on residue & boundary protection. Some people with rare collectible vehicles go so far as to pull the plugs and crank the engine until pressure comes up, then they replace plugs & start. Differing priorities & levels of paranoia.
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David
 
OneQuartLow, I know it's not a big issue, I just wasn't sure how priming an oil filter thats right next to the oil pan could really help shorten the time it takes to build pressure thats all.
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Jason
 
Patman, I never considered priming the oil filter on my Honda because it is a horizontal mount. I figure the amount I'd get in there would be negligible.

The only thing I do to filters is completely wipe down the base plate. Lots of loose metal comes off on the rag. I'd hate for that junk to be figured into any oil analysis.
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--- Bror Jace
 
quote:

Originally posted by Bror Jace:
Patman, I never considered priming the oil filter on my Honda because it is a horizontal mount. I figure the amount I'd get in there would be negligible.


You can still get in about 100ml of oil though, enough to soak into the media. Your oil filter mounts the same as my wife's 2000 Civic, and that's what I do with hers. It might only be a little bit, but I'm sure it helps somewhat. It can't hurt.
 
I just started reading this board and find it very interesting.

To add a few additional comments:
this question has been discussed on several other boards - an argument that arose at one time regarding whether the practise of prefilling was recommended or not, prompted me to reread a number of repair manuals I'd been using - many of them actually did recommend prefilling. I had always done it anyway, and even on engines that had horizontally mounted filters.

The next time you remove a used filter, turn it on its side and see how much, if any oil actually spills out - then cut the casing, or punch a hole in it. You may be surprised to see the amount of retained oil.
It is surprising how much oil will be trapped in the media and in the outer area of the casing. The oil in the center tube is a minor portion of the oil contained, and it's only some of that that that will spill out when the filter is turned horizontally.

BTW, it takes a few minutes of repeatedly filling the center tube before enough oil is absorbed through the media to fill the entire casing. The time taken is not critical, I presume, since you're only working for yourself here.
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The fact that fast lube places don't prefill is no justification to not do it. As already mentioned the attitude should be that there is no reason to not do it, and there is a reason to do it - hydrodynamic lubrication is always better than no hydrodynamic lubrication, even for a few seconds.
 
What Midnight said, I have left filters upside down on my drain pan for over a week and still had to stick a nail or something in the backflow preventer flap to let the oil out.
 
When I used to work at Jiffy Lube a long time ago, the only filters we would prime are the diesel trucks. Those filters took a quart of oil easily, and I'm sure a diesel is in bigger need of oil than a normal gas engine when it comes to the filter being dry.
 
Cummins recommends (at least for the 5.9 L engine) that the oil filter be filled with oil before it is installed. Bought a Fleetguard filter for new Cummins 5.9 engine and it was shrink wrapped in plastic. Honda filters are wrapped in plastic. In a magazine called Turbo Diesel Register,which is devoted to Dodge/Cummins, there was an article on how some Cummins motors have been ruined because the cellophane seal that is used on one gallon diesel oil containers or other junk got into the oil. I have always filled oil filters before installing if they are mounted vertically.
 
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