Newbie oil filter question

[SlowPoke]

What are the consequences of using a bigger oil filter assuming that thread size, gasket match up and no physical interference. Someone told me that using a different sized oil filter will cause changes in the oil pressure, so is higher or lower oil pressure better? Finally, can I use OEM oil filters from different car manufacturers?

The reason I'm asking is I just bought 2 OEM oil filters from the parts department of my local dealership and I found that both of them are rusty. In fact, I went back and the clerk told me all the filters on the shelf are like that.

I've found that Toyota oil filters have the same threading and gasket size and since my Daihatsu engine is based on the Toyota Yaris engine, I'm thinking of switching over to using Toyota oil filters. Any comments?

 

[Al]

You need to check on the bypass valve setting for the filters. You can be 2 or 3psi off but not much more.

 

[teamDFL]

quote:

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Originally posted by Al:
You need to check on the bypass valve setting for the filters. You can be 2 or 3psi off but not much more.

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Can you please elaborate. I am about to switch from a bypass valve rated at 16 psi to one rated about 11-13 psi in order to increase filter size like the thread starter, so this is of immediate concern to me.

 

[Gary Allan]

I'm going out on a limb here ..but unless you're anywhere near you oil pumps relief pressure ..I tend to think that the bypass valve setting is to protect the media more than anything else. It just makes more and more sense to me. I can see no purpose that isn't "filter specific" that a bypass valve can serve. Now, admittedly, I can't quite resolve this for filters that don't have bypass valves that rely on in block bypass valves ..but those too should be "spec'd" for that as well.


I would not worry about it. Then again ..I don't worry about too much.

 

[ZR2RANDO]

The 11-13 filter will bypass whenever the pressure drop across the filter is 11-13 psid. The 16 filter will bypass when there is 16 psid across it. The larger filter may or may not see 11-13 psid as often as the smaller filter sees the 16 psid, but will bypass whenever the 11-13 psid is present...just depends on how that filter flows. If all the other variables were the same (media flowrate and effective area), the 11-13 psid filter would bypass a little more often...but with the other variables being different, it would be hard to tell...We have all been trying to figure out just how often they really are bypassing...don't have all that many before and after pressure gauges set up

 

[TC]

"You can be 2 or 3psi off but not much more."

The OEM stock replacement filters for my 2002 Mopar vary from 8 psi to 22 psi, depending on brand. No apparent rhyme or reason for this particular engine.

My opinion -- and it's just an opinion -- is that as long as you're in the ballpark, you're OK. In one of their catalog sections, Baldwin groups bypass settings as low (roughly single digits), mid (teens), and high (20s-30s, such as for some German rides) pressure settings. These broad groupings make sense to me.

 

[Gary Allan]

quote:

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The OEM stock replacement filters for my 2002 Mopar vary from 8 psi to 22 psi, depending on brand. No apparent rhyme or reason for this particular engine.

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This is what sorta leads me to believe it's for the media's benefit. That is, the bypass setting is just to limit that stress to that psi. The Euro stuff with the 20-30 lb bypass settings have got to have a more substantial media to withstand that differential (better center tubes, etc.).

quote:

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don't have all that many before and after pressure gauges set up

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I'm working on it.

I'm almost setup for my "how to end the bypass valve debate test" ..maybe one more week.

 

[ZR2RANDO]

I think we are all waiting on it!

 

[TC]

I went and checked several OEM stock replacement filter bypass settings for my 2002 Mopar 3.0 V-6:

Fleetguard LF3462: 8 psi
Purolator 14459: ~14-16 psi
Hastings LF565: 20 psi

Officially file this under "Go figure."

"This is what sorta leads me to believe it's for the media's benefit. That is, the bypass setting is just to limit that stress to that psi."

I've often suspected that was part of the design factor as well. Some folks say, "That engine NEEDS XX psi bypass." I've always thought that the media (and overall filter assembly) has a big say in the matter as well, so Wix and Purolator filters (two random brands) might "need" two different bypass settings for the same engine.

"The Euro stuff with the 20-30 lb bypass settings have got to have a more substantial media to withstand that differential (better center tubes, etc.)."

Insightful comment! I hadn't thought of that. German filters aren't just better built because of a quality mindset, but because there's an engineered NEED for same brought about by higher pressure differentials..??

[ March 03, 2005, 08:16 PM: Message edited by: TC ]

 

[Gary Allan]

I believe that this is so ..but let's not grasp too tightly to this revelation here. Otherwise next thing you know everyone will be going out and looking to filters with high bypass valve settings to get "better media" without any rhyme or reason to it.

After I do my test(s), it should be a little more apparent what goes on inside (or at least on either side) of the filter. Then, with some amount of data, people can make more intelligent decisions.

 

[ZR2RANDO]

Just keep in mind that if the filter is bypassing then it has achieved that stated psid, and the oil pressure on the clean side has been lowered by that amount. Comes back to what is more important to you...keeping cleaner oil no matter what price (oil pressure loss), or keeping oil pressure (flow) even if it is partially not filtered...
I think you are right about the psid rating for the filters though...it is an indication of how strong that cartridge/media is.

 

[Gary Allan]

Z-man. I don't think that occurs unless you're up against the oil pumps releif settings. You see the same flow ..100% ..you should see the same pressure downstream. You should see "higher" pressure between the pump and the dirty side of the filter.