Originally Posted By: Le_bow_ski
A tear provides a very low resistance path for oil flow in comparison to flow through the filter media, and so will pass a significant amount of unfiltered oil.
Consider the volume going through the filter. Then look at the "tears" reported with pictures.
There is absolutely no way that "a significant amount of unfiltered oil" can pass through two to four 1/4 inch slits in comparison to what goes through the filter during engine operation. The grunge on the filter media in each picture supports that.
The bypass permits a lot more oil than that to go through in normal operation, and you're not reading an outcry that bypass valves be eliminated.
In the real world a certain amount of unfiltered oil goes through a filter which is perfectly manufactured. If we add a couple of small slits to the medium, which increase that amount by some tiny margin, nothing particularly worth noting occurs during operation.
It is interesting that these slits don't show any signs of spreading or increasing, nor do they become larger holes rather than tiny slits or imperfections. I would hypothesize, then, that this is not a problem with the filter media, although it might be.
Obviously tears in the media are not desirable, and Purolator no doubt is aware of the reports and is looking into it. However, the near hysteria appears to be unwarranted.
A tear provides a very low resistance path for oil flow in comparison to flow through the filter media, and so will pass a significant amount of unfiltered oil.
Consider the volume going through the filter. Then look at the "tears" reported with pictures.
There is absolutely no way that "a significant amount of unfiltered oil" can pass through two to four 1/4 inch slits in comparison to what goes through the filter during engine operation. The grunge on the filter media in each picture supports that.
The bypass permits a lot more oil than that to go through in normal operation, and you're not reading an outcry that bypass valves be eliminated.
In the real world a certain amount of unfiltered oil goes through a filter which is perfectly manufactured. If we add a couple of small slits to the medium, which increase that amount by some tiny margin, nothing particularly worth noting occurs during operation.
It is interesting that these slits don't show any signs of spreading or increasing, nor do they become larger holes rather than tiny slits or imperfections. I would hypothesize, then, that this is not a problem with the filter media, although it might be.
Obviously tears in the media are not desirable, and Purolator no doubt is aware of the reports and is looking into it. However, the near hysteria appears to be unwarranted.