Will a smaller oil filter increase oil pressure?

[drivewaytech]

My wife's 06 Chrysler Sebring with the 2.7L V-6 has had a steadily worsening lifter tick for quit some time now. I just recently finished a clean phase of Auto-Rx and now started the rinse phase. The tick progressed from an occasional occurrence after the car had been driven for a long period of time (started about 8 months ago) to ticking at every start up and often ticking during the entire duration of the engine running. During the clean phase, the lifter tick regressed back to every start up ( for about 40 seconds ) and random ticking during operation. ( 1 out of 6 runs ) I changed the oil this past weekend to do the rinse phase and used a SuperTech ST16 oil filter. The ST filter is much smaller than any other manufacture's filter, it's about a half inch shorter. I cranked the car this morning for the first time since the oil change, which so happened to be the coldest morning thus far this season. I was amazed that there was absolutely no tick what so ever. This may be due to the rinse phase

or the smaller oil filter. I wonder if the smaller oil filter increased my oil pressure allowing a slightly stronger flow to charge up that failing lifter. Any thoughts?

 

[TallPaul]

Oil filter size (not considering extremes such as a 10 gallon filter or a 1 liquid ounce filter, which would create a constriction by sheer smallness) should not affect pressure once engine is running, but on start up the smaller filter may allow pressure to come up quicker if there was any drain back out of the filter.

MORE THAN YOU ASKED FOR (and maybe all wrong because this is more or less specultation mixed with partial experience), BUT:
Interestingly my hyperbolic examples are fun to look at as they may reveal properties that are occuring on normal sized filters, but that are not occuring at a significant level. For example, the 10 gallon filter would likely smooth out pressure pulses so that when you gun the engine, the oil pressure gauge needle would not jump near as quickly and unless you held the higher rpm might not jump as high. This effect would be negligible for any normal sized filters. This "buffer tank" effect is handy in some RV water system to smooth out the pulses of the water pump and the need for it probably indicates an el cheapo water pump.

 

[drivewaytech]

A few variables in one situation occurring does make the cause difficult to detect. What I do know is that this morning was the most quite start up this car has made is some time. There is the possibility that whatever was obstructing the port on the lifter cleared this morning when I started the engine. I will see how things progress or if the tick comes back. Hopefully there is no other harm to running a filter that is smaller than the OEM filter. The parts book did indicate the ST16 for my vehicle and power train.

 

[TallPaul]

If the filter is specified for your vehicle by a reputable company, I can't imagine it would cause any harm, even though it be smaller than the other brands filters for that application.

 

[INDYMAC]

I have found filter brand to be a very significant piece of the puzzle when it comes to cold engine start-up noise in my 2000 Tundra V-8. OEM and K&N filters are routinely poor choices, and PureOne and Wix filters are consistently good choices (no knocking or ticking).

Since you have found a filter brand that works, stay with it and be happy!

 

[Gary Allan]

I don't know about your Tundra ..but I believe the Titan V8 has some variation of this BMW pump. It's sorta like a "displacement on demand" pump. It throws all of my perceptions of oil filters out the window.

I don't think I'm going to be able to setup a set of "rules" (for myself) with this type of oil pump as it increases in popularity.

 

[labman]

I think the filter size would have much more effect on how much it is in bypass than the oil pressure.

 

[Gary Allan]

Originally Posted By: labman
I think the filter size would have much more effect on how much it is in bypass than the oil pressure.



Not typically. When in relief it may make a difference ..but it's just a slow down in velocity and is usually minimal compared to the restriction of the engine.

 

[OVERKILL]

Looks like an outboard/stern-drive impeller of sorts!

 

[Gary Allan]

I can't get wrapped around it. I had a good diagram of one such style pump way back, but can't find it now. It has a limited feedback loop for relief and, as close as I can integrate, something like a centrifugal advance. AFAIK, the feedback loop applies the go juice that opens the vanes to provide more volume.

It's gone beyond my ability to reason it.

In the Nissan Titan V8 it keeps a level oil pressure until the upper rpm range ..but that CAN be altered by filter choice as indicated before warm up. It's very confusing for me and upsets all of my paradigms

 

[OVERKILL]

Sounds like reinventing the wheel to me........

 

[Gary Allan]

Changes in oil pumps are well on the way in the higher end Euro's ..but those German engineers have little to do except complicate stuff. I mean, it's all good, but I don't see them really doing anything of merit without a massive price tag to it.

They see no problem with expending 99999% increased effort to achieve .000000001% improvement.

They're trying to achieve the speed of light ..and could care less what Einstein has to say about it.

 

[INDYMAC]

I don't really know if the Tundra pump is displacement on demand (variable displacement?), but I guess it's possible. My oil pressure gauge reads high with cold oil and drops as the oil heats up. It also increases as I give it throttle. I'll try to find a diagram today to see if it is similar to the BMW pump.

Theoretically, I always thought the K&N filter would be my best choice for this truck. But it turns out to be one of the poorest performers on start-up. The original OEM filters did not work well either (nitril ADBV). The most restrictive filter I've tried, PureOne, has been the consistantly best performer, followed closely by the Wix.

Since the filter is mounted horizontally, I suspect that ADBV reliability is the issue. Over a short period of time, some start to leak, and some don't.

 

[TallPaul]

What about an electric oil pump with a constant flow? Or the flow could be automatically adjusted per engine needs, but certainly not tied to engine rpm like a mechanical pump. Also could have a protective feature that if the pump fails then the engine cuts out.

 

[Gary Allan]

Originally Posted By: INDYMAC
I don't really know if the Tundra pump is displacement on demand (variable displacement?), but I guess it's possible. My oil pressure gauge reads high with cold oil and drops as the oil heats up. It also increases as I give it throttle. I'll try to find a diagram today to see if it is similar to the BMW pump.

Theoretically, I always thought the K&N filter would be my best choice for this truck. But it turns out to be one of the poorest performers on start-up. The original OEM filters did not work well either (nitril ADBV). The most restrictive filter I've tried, PureOne, has been the consistantly best performer, followed closely by the Wix.

Since the filter is mounted horizontally, I suspect that ADBV reliability is the issue. Over a short period of time, some start to leak, and some don't.


You appear to be ONLY talking about start up rattle ..there shouldn't be too much difference a filter can make in a functional scenario. There are surely pump efficiency percentages at different viscosity ..but I've personally never seen it being a factor in regard to the filter. The whole thing should be 100% factored to make one filter as inconsequential any other.

That is, when you can perceive a difference ..other than the fatigue of the nitrile ADBV, then something else is "unright".

 

[tom slick]

That pump is a variable displacement vane pump. not that odd in hydraulic applications, very odd on engines. a "vickers pump" is the same concept but different construction.