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Old 01-10-2012, 10:14 PM   #1
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Oil Filter Thread!

I want to start out by saying that i really enjoyed Tom's "Engine Oil Weight" thread. I know a few people went back and forth in disagreement, but in the end I believe we learned a lot (I certainly did).

I have done some searching on this forum and have found very little discussion on oil filters. So, in the spirit of learning more, I hope this thread adds to our knowledge of oil filters.

I will start by telling you what I think I know. I did some research on oil filters a few years back and have taken apart many filters since then. Here is what I learned.

There are 3 basic functioning parts within the filter:
1-Filter media (obvious)
2-Bypass valve (allows oil to bypass the filter media in case of plugged up media or when oil is too cold/thick to flow through media) This is very important for a couple of reasons. If the bypass valve is too strong or non-functioning, it is possible for the oil pressure to break the filter media and send debris into the engine. If the bypass valve is too weak, it will let dirty oil past the filter all the time.
3-One way valve (In my opinion, this is a critical and often overlooked part of the filter) When the engine is turned off, it is the job of the one-way valve to prevent oil in the passageways from draining back into the oil pan. If this valve is not working properly, you will literally have a dry start every time you start the engine. (I am guessing that some engines may be more susceptible to this than others due to oil pump design, etc.)


1-What brand do you like and why?

2-Has anyone had problems with certain brands?

3-I noticed a few of you using different size filters than stock. I still use the FL-910 but I see some using the FL-400 which I believe is the same diameter but a little taller(which would equal more filter media). Does this make a difference if you still have a stock oil pump? Or is it just peace of mind and more oil capacity?

4-Are there any other sizes being used out there? If so, what are the advantages/your thoughts? I am sure on the highly modded engines you have aftermarket filter set-ups/coolers. I am just wondering about what all is possible with the stock filter mount.

Here is a link on filters that I found interesting: http://minimopar.knizefamily.net/oil.../opinions.html

Last edited by AMMO-Duke; 01-11-2012 at 07:49 PM.
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Old 01-10-2012, 10:43 PM   #2
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Everyone will tell you to either stick with a Ford or Wix filter.
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Old 01-11-2012, 07:13 AM   #3
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Originally Posted by jetrinka View Post
Everyone will tell you to either stick with a Ford or Wix filter.
Apparently I am nobody. Don't stick with the Ford filter. It is unremarkable and there are better alternatives. FWIW, I don't have a Duratec, so I won't give specific recommendations.

@AMMO-Duke: #3 is called the Anti Drain Back Valve (ADBV) and you are correct that it is a very important part of the filter. Without it, when you cut off the engine, oil will back flow through the filter, in so doing pushing out dirt that the filter has previously trapped. Cheap filters (as used in $19.99 oil change specials) often delete the ADBV to save cost.

So, without an ADBV 5000 miles of dirt gets washed back into your oil. No big deal if it will go back through the filter, right? Wrong. One, it has to go through the pump first. Two, on cold start up, the bypass valve is often active so the oil isn't filtered. If you cannot or prefer not to change your own oil, a place that won't tell you what brand of filter they use should never get your business. I have done oil changes for friends and neighbors (typically when they have a baby and can't find the time) and the number of quick lube filters without ADBVs is astounding.

The difficult thing with ADBVs is making sure that they lasts the life of the filter. Modern engines run hotter and specify longer oil change intervals (OCIs). A traditional rubber flap may not survive under these conditions. About a decade ago, Wix pioneered the silicone ADBV, which is good to about 400, IIRC. AFAIK, every reputable manufacturer has since followed suit for their non-budget lines, but Wix remains a solid filter choice. CARQUEST and NAPA filters (regular, not budget line) are made by Wix or were when I last checked.

The final thing on ADBVs is that they are the reason why spin-on filters are superior to canister filters. A canister filter changes only the media, nothing else. Maybe the OEs design in a good ADBV that will last 200,000 miles. Back flow of dirty oil into the engine isn't something I want to trust to a maybe.

Unlike many cases where so-called premium parts are just the same part in a fancy box (and I worked in product management for a major aftermarket parts chain so I know this is the case), premium filters are often better. Champ Labs is the largest filter manufacturer, making many different brands, including the K&N and Mobil1 oil filters. These two products are made on a separate production line using dedicated materials. They are not simply a case of taking a well established name and making money off it. If you can get either of these brands for you car, you should. They are not identical, and given the choice (which I have since I run a filter from and SBF and everyone makes that) I go with Mobil1 since they have a more advanced media last I saw. Purolator Pure1 are also superlative and worth the cost premium, IMO.

As for swapping to a different filter, AMMO-Duke has covered most of it. Physical fit trumps everything else and bigger is almost always better. There is simply no substitute for media area. I use the Wix website because they make it easiest to find the specs and have great coverage. Interchange from there is easy. From what I have read, there are some filters that incorporate a second ADBV to help with VCT systems at start up, so don't assume that you can swap to a different filter. Cut one open (they are under $10) and make sure.

The other thing to consider is the bypass valve (AMMO-Duke's #2). It is OK to go to a higher setting, but not a lower one. You can assume that the filter is capable of withstanding the extra pressure, but you don't want oil not being filtered more often than the manufacturer specified. There will always be a pressure drop across the filter, but the engine has some influence as well. Most bypasses are in the 8-11 psi range, but if your OE filter is higher, don't drop down.

One last opinion. Unless you have a racing engine that is built solely for racing with engine clearances to match, don't use a racing filter. Racing filters are designed to ensure maximum flow and pressure under conditions that a normal engine won't see. Unless you are pulling the engine apart on a regular basis, you simply don't have the oil loss that these filters are designed to work with. Stick with a high quality factory replacement type filter and leave the racing filters to the guys who have an engine department.

Good topic AMMO-Duke.
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Old 01-12-2012, 09:52 AM   #4
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Couple of items I might add
I have a 2.3 Duratec and the filter is at the front of the engine, hanging verticle, so it won't drain. Don't know about the other engines.
Second, my prior car was an Eagle AWD turbo. Changed oil at 5k. Usually I would get lifter tick at about 3k, this for many changes. Changed to Mobil 1 filter, never got the tick again. Crap that isn't filtered out (very small particles) builds up) and I believe ultimately theres enough to clog the clearances on lifters. The M1 did a better job
I also use the longer filter which is speced for the truck engine-a little more capacity
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Old 01-12-2012, 12:09 PM   #5
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Good info everyone, thanks!
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Old 01-12-2012, 12:16 PM   #6
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Originally Posted by PDQEagle View Post
Couple of items I might add
I have a 2.3 Duratec and the filter is at the front of the engine, hanging verticle, so it won't drain. Don't know about the other engines.
You are probably correct, but not certain. It depends on the way the oil passages are. If there is a long enough passage out of the filter, there is a possibility that the head pressure would be significant enough to push back some oil in the filter.

It is not nearly as much of an issue as with a horizontal filter, but if there is an ADBV in the factory filter, don't think you are in the clear just because you have a vertical filter.

One other, peripherally related thing. One of the best practices is to fill your oil filter with fresh oil before you screw it on. With a vertical filter, there is absolutely no reason to not do this. Oil pressure will come up much faster after an oil change if you follow this advice.
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Old 01-14-2012, 01:58 PM   #7
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Ok, so which filters on the market other than Wix have a good ADBV and is there somewhere to get info on filters? I have 147k on my car and hope to make it to at least 200k before I can buy a new one (Yup I want another Focus). I do mostly highway driving and about 100m/day, I do change the oil at the recommend 5k, sometimes early at 4k, so if I spend a couple bux more on a filter it's worth it to me.
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Old 01-14-2012, 02:26 PM   #8
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ive got 180k +. only used ford filters and oil. ive beaten my car everyday for the 5+ years ive owned it. 140k miles ive put on myself.
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Old 01-14-2012, 03:51 PM   #9
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That's intense, Daryl. I to the time to read all that wow. I've been using motorcraft filter's w/ Mobil 1 since new.
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Old 01-14-2012, 05:06 PM   #10
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My go-to combo for a long time has been Puralator Pure-One. With those and Mobil-1, my F-150 (4.6 V-8) has gone over 185,000 miles. Therefore that is what I've been using on my Focus.
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