High filtration vs oil pressure

[DrRoughneck]

In another thread someone reported oil pressure problems with aftermarket filters, here: http://www.bobistheoilguy.com/forums/ubb...ck_#Post2920238

According to the OEM statement, it seems high-percentage filters restrict flow and cause the oil pressure to fluctuate in the engine causing "knocks". In this case low pressure in the hydraulic tensioner caused chain slap.

I had been wondering why Toyota puts OEM filters rated at only 50% filtration in Lexus/Toyota engines while Fram and others market filters with 99% filtration. Now I know why: it seems that too much filtration restricts the flow of oil and in certain engine designs where oil pressure is used to control critical components (like the chain tensioner) this can be very detrimental.

And so for EOMs like Toyota it is wiser to sacrifice filtration for flow.


But honestly I have to admit that I do not know where the oil port operating the belt tensioner is usually located. My guess is that it's after the filter and a restrictive filter causes a high pressure difference between the inlet (where the oil pump pushes the oil) and the outlet, so the oil pressure at the outlet and the oil tensioner could be too low.

Can anyone confirm or correct me regarding whether oil pressure is the one before or after the filter?

 

[Rolla07]

I have used all sorts of filters with varying efficiency without any issues, and many have used lower efficiency filters for hundreds of thousands of miles with no engine related issues.. so its mfr preference, I dont think we can say one is superior than an other.

 

[ARCOgraphite]

The filter is AFTER the pump typ and empties into the mains drill gallery feed.
There may or may not be a 2ndary bypass in the filter mounting assy. Oil typ. is bypassed around the pump proper to limit peak operating pressure in the mains. so a lot of oil may be going into the pan NOT into engine bearing/hydraulics oiling.

 

[ZeeOSix]

Originally Posted By: DrRoughneck
In another thread someone reported oil pressure problems with aftermarket filters, here: http://www.bobistheoilguy.com/forums/ubb...ck_#Post2920238

According to the OEM statement, it seems high-percentage filters restrict flow and cause the oil pressure to fluctuate in the engine causing "knocks". In this case low pressure in the hydraulic tensioner caused chain slap.


My theory is the whole Hyundai/KIA "restrictive aftermarket oil filter" thing was probably started by someone using counterfeiter filters which were total junk and indeed didn't flow well - maybe not even having a proper bypass valve.

To cover themselves, Hyundai/KIA put out a TSB stating to only use OEM filters. That is the only way they could cover themselves. Also, some of the Hyundai/KIA engines may not be using positive displacement oil pumps, which would make the engine way more sensitive to oil filters ability to flow oil.

Read this thread. The PureOne which is rated at 99.9% @ 20 microns flows very well ... and only has a 5 psi delta-p with 12 GPM of oil flow going through it. When an engine is idling or at low RPM, the delta-p is barely even there - more like less than 1 psi.

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Main=116457&Number=1619451

 

[Kawiguy454]

If you're worried about restrictive flow get an oversize filter with high filtration. There is info all over the place on it.

 

[WillsYoda]

Oversized filters like the Fram Ultra XG3600 for my corolla might flow better.

 

[4wheeldog]

Originally Posted By: DrRoughneck
In another thread someone reported oil pressure problems with aftermarket filters, here: http://www.bobistheoilguy.com/forums/ubb...ck_#Post2920238

According to the OEM statement, it seems high-percentage filters restrict flow and cause the oil pressure to fluctuate in the engine causing "knocks". In this case low pressure in the hydraulic tensioner caused chain slap.

I had been wondering why Toyota puts OEM filters rated at only 50% filtration in Lexus/Toyota engines while Fram and others market filters with 99% filtration. Now I know why: it seems that too much filtration restricts the flow of oil and in certain engine designs where oil pressure is used to control critical components (like the chain tensioner) this can be very detrimental.

And so for EOMs like Toyota it is wiser to sacrifice filtration for flow.


But honestly I have to admit that I do not know where the oil port operating the belt tensioner is usually located. My guess is that it's after the filter and a restrictive filter causes a high pressure difference between the inlet (where the oil pump pushes the oil) and the outlet, so the oil pressure at the outlet and the oil tensioner could be too low.

Can anyone confirm or correct me regarding whether oil pressure is the one before or after the filter?


Something I read on another forum years ago, written by a guy who had done a lot of testing of OEM filters, was that Toyota had a different philosophy concerning filters.....Their air filters were more efficient than anybody elses, but their oil filters were average, or less. The theory being, the problem particles get into the engine through the air filter. If the air filter is superior, the oil filter doesn't have to be.

This does not account for particles formed in the crankcase. But Toyota apparently is less concerned about those, than the silica allowed in by poor air filtration. YMMV.