On 12/10/2016, Tom Chapple in San Luis Obispo, California USA wrote:

Felt Oil Filter Element

"Recently I had an oil filter failure pretty much identical to that described in OF-100F. It is rather amazing that his photo of the destroyed oil filter is identical to what I experienced this past month – also with a felt filter. I tore the engine apart to find major fragments of metal, a spun center main bearing and otherwise bad news requiring a major re-build of an engine that was entirely rebuild just 13K miles ago. .... I am definitely staying away from felt filters in the future".

When it happened in 2011, no one had never seen this problem before, and maybe never again since. As long as it is a single occurrence they call it a freak and figure it will never happen again so they ignore it and keep selling the felt filters.

Now that it has happened again, there must be a reason, and it is predictable that it will happen again, unless someone figures out why it happens and fixes the problem. It may be something like a change of additives in modern motor oil where something new will make the felt material decompose. More likely it is a manufacturing fault of felt material with too low density, or maybe different type material used to make the felt, or insufficient mechanical retention of the felt in the filter element.

Until such time as someone can determine why this happens, and fix it, I can only recommend that no one should ever use a felt filter again.

On 12/13/2016, Tom Chapple wrote:
"The above picture is the second filter that disintegrated for me. I had my ’58 MGA on-the-blocks for several months in 2016. Prior to re-start, I decided to change the oil because it had been 2K miles and the oil looked very dark. Upon pulling the filter, I found it 90% destroyed and 1/2 teaspoon of metal filings were sitting in the bottom of the oil filter canister. After consulting with others, I installed a new felt oil filter, fresh oil and cautiously drove the car. This engine had been rebuilt 5 years and 13,000 miles previously. After 75 miles of driving on the fresh oil & filter, I became alarmed by extremely low oil pressure. I pulled the pan and found more than a tablespoon of metal filings and once again a mostly shredded oil filter (picture above). It’s very hard to say what the sequence of events were inside the engine, yet upon tear-down the main and rod bearing were seriously eroded with evidence of metal filings passing through. In closing, for me, it’s no more felt filters".

"As a side-bar, I did purchase these filters through Moss Motors. I took the first of the two filters to Moss via the local British shop where I purchased it. I will soon take the second filter as well".