MichaelBenz

iTrader: (2)

For those that didnt know how oil flows through an oil filter or what is inside of that spin-on canister...here is the mystery solved for you!


Information taken from Acura Service Consultant Illustrated Technical Guide,
Copyright 2005, American Honda Co.Inc.

TBone2004

How much junk does an oil filter capture? With all the threads on which is the best one and people have taken them apart etc....anyone have a picture of a used filter - opened up? We all have seen our air filters and cabin filters and can see the junk caught - so it makes you feel like it is important to be there, but any proof of what the oil filter does? Just curious.

TBone2004

what does the oil by-pass valve do?

MichaelBenz

iTrader: (2)

#1..the oil by-pass allows oil to flow through in the event that the filter is too dirty to properly pass the correct amt of oil through, ect as well as allows, in extreme circumstances, thicker viscosity oil to pass until warm enough to go through the filter correctly during start up. (in a real simplified "nutshell answer there).

I will work on the old filter cut open for you....seen it many times....but I will cut one open for you when I get an old one on hand. Gonna be a few months though....just changed oil.

Thorin78

Has MichaelBenz replaced Roadrage in our instructive learning classes?

Thanks MB, I like reading all this stuff.

MichaelBenz

iTrader: (2)

Q. How does the oil filter work?
A. The vast majority of oil filters used in automobiles today are full flow filters. With this type of system, all of the oil is filtered before it passes into the engine. Full flow filters must provide low restriction to oil flow while having a high degree of single pass efficiency. This means that a filter must remove as much engine-damaging dirt and grit as possible from the oil on the first time around.

Pleated Media. The majority of automotive oil filters today use pleated filter media, which increases surface area for high filtration efficiency within a relatively small space. However, the number of pleats in the media does not have as much bearing on filtration efficiency as the quality of the media itself. With thicker, high-quality media, the filter design may, in fact, call for fewer pleats to improve fluid flow and filter performance.



Q. What causes over-pressurization?
A. Over-pressurized Filters. From time to time, a used oil filter will appear bulged or deformed. A bulged oil filter is one that has been subjected to too much pressure -- a condition that occurs when the oil pressure regulating valve is malfunctioning. When a bulged oil filter is discovered, the pressure regulating valve should be serviced immediately.

What causes over-pressurization? Excessive engine oil pressure is the result of a faulty oil pressure regulating valve. To properly separate the engine parts and prevent excessive wear, the oil must be under pressure. The pump supplies oil at volumes and pressures greater than what the system requires to lubricate the bearings and other moving parts. The regulating valve opens to allow excess volume and pressure to be diverted.

There are two ways that the valve fails to operate correctly: either it sticks in the closed position, or it is slow to move to the open position after the engine has started. Unfortunately, a stuck valve can free itself after filter failure, leaving no evidence of any malfunction.

Note: Excessive oil pressure will cause filter deformation. If the regulating valve still remains stuck, the gasket between the filter and the base can blow out or the filter seam will open. The system will then lose all of its oil. To minimize the risk of an over-pressurized system, motorists should be advised to Change the oil and filter often.



Q. What valves are in oil systems and are they in the oil filter?
A. Oil Pressure Regulating Valve. The oil pump pressure regulating valve, usually built into the oil pump, helps control the operating pressure of the lubrication system. The regulating valve is set by the manufacturer to maintain the correct pressure. The valve utilizes a ball (or plunger) and spring mechanism. When the operating pressure is below the preset PSI level, the spring holds the ball in the closed position so that oil flows to the bearings under pressure. When the desired amount of pressure is reached, the valve opens enough to maintain this pressure. Once the valve is open, the pressure remains fairly constant, with only small changes as the engine speed varies. If the oil pressure regulating valve becomes stuck in the closed position or slow to move to the open position after the engine has started, the pressure in the system will exceed the regulating valve setting. This may cause an over-pressurized oil filter. If a deformed oil filter is observed, the oil pressure regulating valve must be serviced immediately.

Relief (By-Pass) Valve. In a full flow system, all of the oil passes through the filter to reach the engine. If the filter clogs, an alternative route to the engine must be provided for the oil, or the bearings and other internal parts may fail, due to oil starvation. A relief, or by-pass, valve is used to allow unfiltered oil to lubricate the engine. Unfiltered oil is far better than no oil at all. This relief (by-pass) valve is built into the engine block in some cars. Otherwise, the relief (by-pass) valve is a component of the oil filter itself. Under normal conditions, the valve remains closed. When there is sufficient contaminant in the oil filter to reach a preset level of pressure differential to oil flow (around 10-12 PSI in most passenger cars), pressure differential on the relief (by-pass) valve causes it to open. This condition can occur when the oil filter has become clogged or when the weather is cold and the oil is thick and flows slowly.

Anti-Drainback Valve. Some oil filter mountings may allow oil to drain out of the filter through the oil pump when the engine is stopped. When the engine is next started, oil must refill the filter before full oil pressure reaches the engine. The anti-drainback valve, included in the filter when required, prevents oil from draining out of the filter. This anti-drainback valve is actually a rubber flap that covers the inside of the inlet holes of the filter. When the oil pump starts pumping oil, the pressure will unseat the flap. The purpose of this valve is to keep the oil filter filled at all times, so when the engine is started there will be an almost instantaneous supply of oil to the engine.

Anti-Siphon Valve. When a turbocharged engine is turned off, it is possible for the turbocharger’s lubrication circuit to siphon oil from the oil filter. To prevent this from happening, the turbocharged engine’s oil filter is equipped with a specially designed, one-way, shut-off called the anti-siphon valve. Oil pressure keeps this spring-loaded valve open while the engine is turned on. When the engine is turned off and oil pressure drops to zero, the anti-siphon valve automatically closes to prevent the back-flow of oil. This valve insures that there will be a continuous supply of oil available to the turbocharger and the engine’s lubrication system upon start-up.

Not On Dry Starts: If a vehicle has not been operated for several days or after the oil and filter is changed, some oil may have drained from the filter in spite of the special valves. This is why it is always a good idea to start the engine slowly, letting it run on idle for 30-60 seconds so the lubrication system will be fully charged with oil before a heavy load is placed on the engine.
From Fram Filters, USA

TBone2004

Thanks I'd appreciate that very much - would be very interesting to see.

MichaelBenz

iTrader: (2)

In a nutshell...here is what you will see...



You can see the filter and still inside the filter canister you can see a small bit of the bypass valve at the bottom (which is actually the filter top). It appears that this filter has been cut right by the base.

SodaLuvr

Go to bobistheoilguy.com and take a look at many filter pics for yourself.

Anyone have any questions regarding filters? I'm too lazy to write something in general but can try to answer specific questions regarding the different filter designs, efficiency ratings, bypass valve location placement, endcaps that don't use glue, etc...

BTW, RR won't be on this forum for a long time, just FYI.

scrb09

WHY?

and BTW great info MB.

TBone2004

he got all offended that people here were not appreciating his input. His info was great until he began preaching that his way was the only way...so he bailed to go hang with more "intelligent" people - folks that still worship him and do not contradict him.

MichaelBenz

iTrader: (2)

Thats really unfortunate....his stuff was always a good read.

MichaelBenz

iTrader: (2)

Hey...no problem! Glad you enjoyed it.

Ron A

Click here for a link to inside pictures of loads of oil filters.

MichaelBenz

iTrader: (2)

Thanks Ron! I must admit...I wasnt looking forward to cutting open the next old one for him to see (very messy)! He can check just about as many as he wants out in that spectrum!

HiTEC

This dude has a lot of good stuff on his site too.

http://www.frankhunt.com/FRANK/corve...lterstudy.html

He was threaten with a lawsuit so he tries to just gives the facts, rather than his opinion. He had to take some of his opinionated stuff off the site.

SodaLuvr

I like the BITOG in-house filter study with more technical info, better than the other links:
www.oilfilterstudy.com

TBone2004

well actually I was looking to see a used one - any of these links used ones? I have clicked several but no luck. Not really interested what they look like new - just curious how much dirt/junk is captured.

MichaelBenz

iTrader: (2)

Ah....I see.....I'll crack one open for you then. Give me time.

SodaLuvr

I've got tons...just give me the brand/model/part # and I'll try to find a pic of one for you, used.

You really can't tell how much dirt/junk is captured. This is one of the common misconceptions about cutting open a filter. What you'll see is that the media would've been discolored due to normal use (usually a grayish color), but you won't see actual pieces of debris or sludge unless your engine was dirty, and the oil was actively cleaning.

The only reason you cut open the filter is to see if there were any holes in the media, any ripped pleats, condition of ADBV, bypass valve, etc...

SodaLuvr

OK. Here are some pics of an Adv. Auto Totalgrip filter (Purolator Premium Plus clone) AA7317 from an 01 Civic with 65K, used for an Auto-RX rinse phase (no more than 3K).

Can and top gasket


Bypass Valve


Pics of Internal Parts


Closeup view of Filter media:


Rubber (Nitrite) Anti-Drain Back Valve (ADBV)

MichaelBenz

iTrader: (2)

Thanks Michael....again, saved my grinder a cleanup!

TBone2004

Hey guys I REALLY appreciate the effort! Thanks!


Great pics - thanks a million!

tmitch2315

A routine check is done on aircraft oil filters where they are cut apart then the media is cut out along each edge of the canister turned inside out then spread out in one piece to look for any unusual debris or small flakes of metal which can be seen when you hold it under a strong light or in the sun. Interesting process and its amazing what gets trapped in there. Quick way to split the filter is to put it in a vise do a deep scoring with a hack saw all the way around then hit it with a chisel at an upward angle a few times and open it pops. This way no metal from the opening process get into the filter before inspection. There is also a very expensive pipecutter type device that will do the same thing even faster.