Originally Posted by USNA1970

I took apart my stock oil filter canister. The bypass in the bottom of the canister will pop out if you pull on it with plyers. The spring bypass mechanism seemed fully intack and still pretty strong. Meaning, I don't think the spring weakened compared to the new canister I purchased. I really wonder how much bypassing really happens if you don't push the car during cold start. I am saying that old spring still seemed to be seating very firmly.

Originally Posted by docmirror

Ok, but I'm going to explain why this still doesn't make sense. I'm not adverse to intriguing solutions to failure, but not sure where this goes.

As its name implies, a scavenge pump draws up fluid from a distant location, and returns it to a well. In the oiling system of an engine, it would take the oil AFTER having gone through the circuit(including all the bearings), and delivering it to the sump, where the mag drain plug resides.

Second, presuming the failure mode is ferrous where a magnet would help, we're talking about scarf from the IMSB, IMS, crankshaft, rods, oil pump housing, or cams. I"m guessing there's more Fe in the engine, but these are the big things that release Fe into the circuit. I can presume that if one of the cylinders begins to come apart(D-chunk), we're done for the day, and even the largest magnet in the world will do no good.

Presumably, we're looking at detritus from the failure prone IMSB as it begins to disintegrate. As the IMS and bearings are below the crankshaft, the majority of the oil windage from the IMS and bearing are going to go right in the sump, not anywhere near the scavenge pumps, as they say - Elvis(oil) has left the pressure circuit. But - I will admit that I have no idea where they are in the engine, it would be strange to find them near, or below the IMS, where they might be suitable to put a magnet for protection. I'm willing to be advised otherwise of course.

Lastly, as I mentioned, a magnet presumes to retain the particles in the engine, where they live on forever until the engine is taken down. I want whatever is in there, to come out of there, and leave via the oil, filter, or mag outside the filter, or manual cleaning of the drain plug. I don't want it to stay in the engine where it's another little time bomb just waiting to be released into the oil circuit again.

Originally Posted by Porschetech3

Correct !. The bypass just pops out of the bottom of the canister. That's the only real problem I have with the factory bypass is it sits in the bottom where any heavy metal debris will also sit. Some filter systems have the bypass at the top which is a much better place to bypass. The bypass can open at cold starts when a large pressure differential is present across the filter until the pressure equalizes across the filter.

To answer the OP question (sorry I missed this thread) about disabling the factory bypass, I have been doing this for years on my 3 m96 cars currently on the road. A 99 Coupe, A 99 Cab, and a 986 (with S engine ). Simply by poping out the bypass, cleaning it, and fill the cup with Loctite E-HP120 epoxy, then let it sit overnite and install. I use the K&N Pro Series PS-7011 cartridge filter $5. high flow, has a good internal strength cage to prevent collapse, haven't had a collapse even using M1 5w-50 or even 15w-50 in winter, and yes I do track these cars.

The only issue with disabling the bypass is that it takes a moment to reach max oil pressure on cold starts.Although I feel with the larger surface area of the K&N PS-7011 vs the Napa 1042(non-pypass filter) with similar density filer media of 25-30 microns, the K&N will reach max pressure quicker.

The issue with pressure loss due to a stopped up filter from dirt and extended change intervals should be a non-issue. Most 996 owners change their oil at much more often intervals.If you drive your car long enough for the oil filter to stop up due to dirt, then you need your 996 taken away from you anyway !!

Originally Posted by 2005 996 C4S

Hi there, sorry to resurrect an old thread. Great information you are providing here. I was debating getting the LN Engineering spin on to eliminate the bypass however your idea here looks better. This would save money and allow the use of the paper filter which I like for ease of analysis. Would you be able to expand on 2 things for me? You refer to cleaning the bypass, do you use something specific to get all the oil off it to allow adhesion of the locktite product? I haven't looked at this item other than the one time it fell out when i first changed the oil in the car and had to wonder where it came from. You said to fill the cup with locktite, is that the silver little cup on top of it?

Thank you in advance, Not new to working on cars however new to Porsche. I just picked up my first this past June. 2005 996 C4S 26k miles.

Rick

Originally Posted by Porschetech3

Hi, just pop the by-pass out of the plastic can, clean it with brake or carb cleaner then use some rubbbing alcohol on it to remove all the oil. Turn it upside down and fill the plastic cup on the spring side full of epoxy. Fill all around the spring and in the center of the spring untill about level on the cup. Use Loctite E-120hp , it is high temp and oil resistant and adheres to plastic and metal alike. Allow 24 hrs to cure before reinstalling. Simple to do and will stop any oil from bypassing the filter while maintaining the ease of inspection of the filter and retaining the larger capacity filter to allow quicker/more oil flow on cold start compared to the smaller spin on filter element.

Originally Posted by pdxmotorhead

If you do some comparisons,, bigger filter does not always = better performance,,
The bypass in the pump is sufficient, if the filter plugged things have gone way
way wrong already.. IMHO..

Originally Posted by pdxmotorhead

A lot of german cars use "wet" filters, it makes a quick easy way to see scarf in the oil..
They also have a common failure,, the silly plastic housings and caps..

Originally Posted by Porschetech3

True . I agree, but smaller filter rarely = better performance..

I've many many of the Plastic canisters off while servicing ,and haven't seen one fail. I even epoxy magnets around the outside of mine for even better filtering..

Originally Posted by pdxmotorhead

Well it sorta depends on how you define performance,, smaller filters (Used on most cars now,,, )
Fill quicker, so reduce prime time to the system. The working theory that a lot subscribe to
is that the smaller filters somehow flow less, but I've back pressure tested a couple used on
my Jeep which I can get a tall and short filter for,, no difference.. Not flowing 20w50 anyway,,
The resistance to flow was identical with a analog helic gauge.. Now there is probably different filter media,,
and other unknowns,, so we all go with the most comfortable to us choice..

I've replaced several BMW oil filter caps that cracked in use,, they seem to last safely about 50K miles after that your on the timer..
Now these were all heavily tracked cars.. Similar issue to the E46 and onward cooling systems with the
self destruct mode ,, all the plastic gets brittle and typically by 80 to 100 K miles the whole system needs
yarded off and replaced.. (Those that don't often end up replacing the engine...) Also seen it on a couple boats and tractors..

Originally Posted by pdxmotorhead

I've never had a spin on leak,, and that's a lot of years and cars,, good point there that we all have had different items fail..
And folks do tend to dodge the most familiar problems.

I actually prefer a Oberg, with a remote spin on mounted closed end down.. But its not a uber practical setup on a street car..