A Look Inside an Oil Filter
It's just an oil filter! What else do I need to know?!
All oil filters aren't the same. To see if the filter
your using is up to the task open it up with an oil filter cutter.
Oil filter cutters are used by engine builders and auto enthusiasts
to do some forensic work to find out how the engine is doing.
The pics above show how the oil filter cuts into a
filter and what you'll find inside.
2.0L Break-In Oil Filter
After building a custom engine it's a good idea to
open up the oil filter to see what's floating around in the oil.
There are less than 50 miles on this filter. That's plenty for a
new engine break-in.
The picture above shows the various components in
an oil filter. On the left there is the top of the canister. Oil
is pumped in through the small holes around the center. Oil is pushed
out and into the engine through the center opening. The black rubber
disc is an anti drain back valve that keeps the filter full of oil
when the motor is off. The filter media is in the center. And a
spring that keeps the filter media pressed against the top sits
at the bottom. The filter canister is the last part on the right.
The bottom of filter media contains a bypass valve.
Should the oil pressure exceed the spring weight in the valve, oil
will pass through the bypass unfiltered. This prevents damage to
the filtration media, the oil filter gasket and filter canister.
I shoved an allen wrench in the bypass valve to show what opens.
The picture above shows the various components as
well as some sediment in the filter can. That dark crescent shape
is comprised of very fine iron filings as a result of normal break-in.
The filter magnet removed these filings before they even got to
the filter media. If the iron filings are smaller than what the
filter can strain, they will get through the filter and erode engine
parts. The filter magnets do their job.
I'll open up the next filter to see if there's a reduction
Cast iron is porous and will hold onto very fine bits
of metal when the engine is being built. As the engine cycles and
oil passes through it, the fine particles are released into the
oil stream. This is what is seen above.
Identifying a Filter with a Bypass
There are two potential oversized filters that I could
put on the test car. The Purolator L30001 and Purolator L30005 (being
discontinued). They both look the same and have the same dimensions.
There is one difference though. L30001 has an internal bypass valve
and L30005 does not. Because the Chrysler/Dodge 2.4L turbo motor
does not have an oil bypass built into the engine, there should
be one built into the oil filter.
The photos above show how to identify an internal
bypass in an oil filter. The L30005 filter in the left does not
have a rivet at the bottom. The L30001 filter on the right does
have a rivet to support the bypass. If the filter for your car is
suppose to have a bypass, find a larger filter with a rivet or mechanism
at the bottom.
The components in the two oil filters above are similar
to the filter at the top of the page. Instead of a conventional
spring at the bottom, a piece of stamped sheet metal acts as a spring
to hold the filter media at the top of the canister. The bypass
valve shown on the bottom of the filter media in the top right photo
is a different design than the filter for the 2.0L engine at the
top of the page.
There are several types of oil filter magnets on the
market. I'm convinced FilterMags are the best. Simple fridge magnets
would be better than nothing. But there's no way to guarantee that
a weak magnet will stay on the oil filter while the car is in motion.
Rare earth magnets are more than strong enough to not require mechanical
fasteners to cling onto the oil filter. A strong magnet with a large
area can pull iron particles from a fast moving stream of fluid
much better than a small weak magnet.
The outside of the FilterMag is magnetically shielded.
This means bits of metal, tools, bolts etc won't stick to the outside
of the filter magnet. It also means the Filtermag won't leap off
the oil filter and stick to a manhole cover.
Here's a look inside an oil filter with a Filtermag
(bottom left photo). The iron filings inside the filter outline
the magnets stuck on the outside of the canister. When the filtermag
is removed, the iron filings stay in the removed oil filter and
go out with the garbage.
The top right photo shows a close look inside the
filter canister with the fine iron filings separated from the oil.
Filter magnets work. To separate the iron filings for the photo
I used a simple round fridge magnet to hold the filings at the bottom
and poured out the oil. What you see at the bottom of the canister
there is what came off the engine during 3,000 miles of driving
and a few passes at a drag strip.
Get a larger oil filter that meets the engine's bypass
Use an oil filter magnet to remove suspended ferrous
metal from the oil.
I recommend the FilterMag or similar design.
If you're serious, get an oil filter cutter. They're
usually $40 to $60.
Improved Maintenance Topics:
Wiper Arm Adjustment
Copyright 2008 -
2009. Efficient-Mileage.com. All rights reserved.